JP2008241340A - Terahertz wave spectral measuring instrument and method - Google Patents

Terahertz wave spectral measuring instrument and method Download PDF

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JP2008241340A
JP2008241340A JP2007079405A JP2007079405A JP2008241340A JP 2008241340 A JP2008241340 A JP 2008241340A JP 2007079405 A JP2007079405 A JP 2007079405A JP 2007079405 A JP2007079405 A JP 2007079405A JP 2008241340 A JP2008241340 A JP 2008241340A
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Hiromasa Ito
弘昌 伊藤
Yoshie Ota
祥恵 太田
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RIKEN Institute of Physical and Chemical Research
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Abstract

<P>PROBLEM TO BE SOLVED: To provide terahertz wave spectral measuring instrument which spectrally measures a measuring target by producing terahertz waves, with predetermined frequency and efficiently propagating the terahertz wave to a desired region in low loss, and also to provide a terahertz wave spectral measuring method. <P>SOLUTION: The terahertz wave spectral measuring instrument is equipped with: a two-wavelength light source 12 for emitting lights 1 and 2 having two different wavelength; a non-linear optical material 14 for emitting terahertz waves 3, corresponding to the difference frequency components of the two-wavelength lights by a light difference wave generation (DFG); a flexible elongated hollow transmission pipe 16 for internally transmitting the terahertz waves, which are emitted by the close adhesion, approach, and insertion of a non-linear optical material, with respect to an incident end surface to an emitting end surface and a terahertz wave detector 20 for measuring the intensity of the terahertz waves transmitted the measuring target. The hollow transmission pipe 16 is a flexible fiber for a propagating medium or far-infrared rays. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、テラヘルツ波を発生・伝搬させて被測定物を分光計測するテラヘルツ波分光計測装置及び方法に関する。   The present invention relates to a terahertz wave spectrometer and method for spectroscopically measuring an object to be measured by generating and propagating terahertz waves.

本出願において、およそ０．１〜１００ＴＨｚの周波数を有する電磁波、すなわちこの領域の遠赤外線及びサブミリ波を「テラヘルツ波」と呼ぶ。   In the present application, an electromagnetic wave having a frequency of approximately 0.1 to 100 THz, that is, far infrared rays and submillimeter waves in this region are referred to as “terahertz waves”.

テラヘルツ波の発生手段として、２つの異なる波長のレーザ光を非線形光学結晶へ入射してそれらの差周波数分のテラヘルツ波を発生させる差周波発生法が既に知られている（例えば特許文献１，２）。
また、発生したテラヘルツ波の伝送手段として、ガラスないしプラスチックキャピラリの内側に銀鏡反応で銀を成膜した中空ファイバ、強誘電体をクラッドに用いたＰＶＤＦ中空ファイバが知られている（例えば非特許文献１）。 As a means for generating terahertz waves, there is already known a difference frequency generation method in which laser beams having two different wavelengths are incident on a nonlinear optical crystal and terahertz waves corresponding to the difference frequencies thereof are generated (for example, Patent Documents 1 and 2). ).
Also, as means for transmitting the generated terahertz wave, a hollow fiber in which silver is formed by a silver mirror reaction inside a glass or plastic capillary, and a PVDF hollow fiber using a ferroelectric as a cladding are known (for example, non-patent literature). 1).

特許文献１は、主としてミリ波からテラヘルツ波における電磁波を用いてセンシングなどを行うための、低消費電力かつ小型で持ち運び可能な集積モジュールとすることを目的とする。
この高周波電気信号制御装置は、図１２に示すように、高周波電気信号の発生器５０であってレーザ光５１ａ、５１ｂをそのレーザ光よりも低い周波数の電磁波５２に変換する素子を備える。また、レーザ光５１ａ、５１ｂを発生させるレーザ装置５３ａ、５３ｂ、レーザ光５１ａ、５１ｂを伝搬させて発生器５０に導くための光導波路５４、発生器５０、及び信号を伝搬させるための伝送路５５、５７を同一基板上に集積化したものである。 Patent Document 1 aims to provide an integrated module that is low in power consumption, small in size, and portable for sensing using electromagnetic waves from millimeter waves to terahertz waves.
As shown in FIG. 12, the high-frequency electrical signal control device includes a high-frequency electrical signal generator 50 that converts laser beams 51a and 51b into electromagnetic waves 52 having a frequency lower than that of the laser beams. Further, laser devices 53a and 53b for generating laser beams 51a and 51b, an optical waveguide 54 for propagating the laser beams 51a and 51b and guiding them to the generator 50, the generator 50, and a transmission path 55 for propagating signals. , 57 are integrated on the same substrate.

特許文献２は、テラヘルツ波を任意の場所に容易に照射可能であるとともに、既存のシステムや装置を有効利用することによって容易に実用化を図ることを可能にすることを目的とする。
このシステムは、図１３に示すように、２つの波長のレーザ光を同時に発振可能であるとともに該波長を可変することのできる２波長発振レーザ装置６０と、２波長発振レーザ装置から出力された２つの波長のレーザ光を伝送する光ファイバ６１と、上記光ファイバにより伝送された２つの波長のレーザ光を用いて差周波発生によりテラヘルツ波を発生する波長変換手段６３とを有するものである。 Patent Document 2 aims to enable terahertz waves to be easily radiated to an arbitrary place and to easily put it to practical use by effectively using existing systems and devices.
As shown in FIG. 13, this system is capable of simultaneously oscillating two wavelengths of laser light and changing the wavelength of the two-wavelength oscillation laser device 60 and the two-wavelength oscillation laser device 2 output from the two-wavelength oscillation laser device. It has an optical fiber 61 that transmits laser light of one wavelength, and a wavelength conversion means 63 that generates a terahertz wave by differential frequency generation using the laser light of two wavelengths transmitted by the optical fiber.

非特許文献１は、図１４に示す装置を用い、重水素ランプの光をミラーを介して中空ファイバに導き、その伝送損失を試験したものである。   Non-Patent Document 1 uses the apparatus shown in FIG. 14 to test the transmission loss by guiding the light of a deuterium lamp to a hollow fiber through a mirror.

特開２００５−０１７６４４号公報、「高周波電気信号制御装置及びセンシングシステム」Japanese Patent Application Laid-Open No. 2005-017644, “High Frequency Electric Signal Control Device and Sensing System” 特開２００６−１７１６２４号公報、「テラヘルツ波発生システム」JP 2006-171624 A, “Terahertz Wave Generation System”

Ｙ．Ｍａｔｓｕｕｒａ ａｎｄ Ｍ．Ｍｉｙａｇｉ，“Ａｌｕｍｉｎｕｍ−ｃｏａｔｅｄ ｈｏｌｌｏｗ ｇｌａｓｓ ｆｉｂｅｒｓ ｆｏｒ ＡｒＦ−ｅｘｃｉｍｅｒ ｌａｓｅｒ ｌｉｇｈｔ ｆａｂｒｉｃａｔｅｄ ｂｙ ｍｅｔａｌｌｏｒｇａｎｉｃ ｃｈｅｍｉｃａｌ−ｖａｐｏｒ ｄｅｐｏｓｉｔｉｏｎ”，Ａｐｐｌｉｅｄ Ｏｐｔｉｃｓ，ｖｏｌ．３８，Ｎｏ．１２，２０ Ａｐｒｉｌ １９９９Y. Matsuura and M.M. Miyagi, “Aluminum-coated hollow glass fibers for ArF-excimer laser light fabricated by metallic chemical-vapor deposition,” Applied Op. 38, no. 12, 20 April 1999

テラヘルツ波は、光波帯とミリ波・サブミリ波と呼ばれるＲＦ帯の中間に位置し、光波と電波の両方の特性を有する。そのため、テラヘルツ帯において活性である物質の特性解明、特に分光計測に非常に有効なデバイスとして期待されている。
しかし、テラヘルツ波は、水蒸気や水分による吸収が大きいため空気中では発生と同時に急速に減衰してしまう問題点がある。そのため、従来は、テラヘルツ波を用いた被測定物の自由空間中での分光計測が困難であった。 The terahertz wave is located between an optical wave band and an RF band called a millimeter wave / submillimeter wave, and has characteristics of both a light wave and a radio wave. Therefore, it is expected as a very effective device for elucidating characteristics of substances active in the terahertz band, particularly for spectroscopic measurement.
However, terahertz waves have a problem that they are rapidly attenuated as they are generated in the air because they are largely absorbed by water vapor and moisture. Therefore, conventionally, it has been difficult to perform spectroscopic measurement in a free space of an object to be measured using a terahertz wave.

本発明は、かかる問題点を解決するために創案されたものである。すなわち本発明の目的は、所望の周波数のテラヘルツ波を発生させ、これを低損失で所望の部位まで効率よく伝搬させて、被測定物を分光計測することができるテラヘルツ波分光計測装置及び方法を提供することにある。   The present invention has been developed to solve such problems. That is, an object of the present invention is to provide a terahertz wave spectroscopic measurement apparatus and method capable of generating a terahertz wave having a desired frequency and efficiently propagating the terahertz wave to a desired part with low loss and spectroscopically measuring an object to be measured. It is to provide.

本発明によれば、異なる２波長の光を出射する２波長光源と、
前記２波長の光から光差周波発生によりそれらの差周波数分に相当するテラヘルツ波を発生する非線形光学材料と、
該非線形光学材料が入射端面に密着又は近接又は挿入され、発生したテラヘルツ波を出射端面まで内部を伝送する可撓性の細長い中空伝送管と、
該被測定物を透過したテラヘルツ波の強度を計測するテラヘルツ波検出器と、を備え、
前記中空伝送管は、中赤外乃至、遠赤外伝搬用の可撓性の中空ファイバである、ことを特徴とするテラヘルツ波分光計測装置が提供される。 According to the present invention, a two-wavelength light source that emits light of two different wavelengths,
A non-linear optical material that generates terahertz waves corresponding to the difference frequency from the light of the two wavelengths by light difference frequency generation;
A flexible elongated hollow transmission tube in which the nonlinear optical material is closely contacted or close to or inserted into the incident end face, and transmits the generated terahertz wave to the exit end face;
A terahertz wave detector for measuring the intensity of the terahertz wave transmitted through the object to be measured,
There is provided a terahertz wave spectroscopic measurement device, wherein the hollow transmission tube is a flexible hollow fiber for propagating from mid-infrared to far-infrared.

本発明の好ましい実施形態によれば、前記中空伝送管は、中赤外乃至、遠赤外伝搬用の可撓性の中空形状のファイバであり、その両端がテラヘルツ波を通し水分を通さないように密閉され、内部にテラヘルツ波の吸収の少ないガスが密封または真空状態にされている。   According to a preferred embodiment of the present invention, the hollow transmission tube is a flexible hollow fiber for propagating from mid-infrared to far-infrared, so that both ends do not pass moisture through terahertz waves. A gas with little absorption of terahertz waves is sealed or vacuumed inside.

前記中空伝送管は、内部に金属面を有する金属中空ファイバや、ＰＶＤＦ（ｐｏｌｙｖｉｎｙｌｉｄｅｎｅ Ｆｌｕｏｒｉｄｅ）製中空ファイバである。   The hollow transmission tube is a metal hollow fiber having a metal surface inside or a hollow fiber made of PVDF (polyvinylidene fluoride).

また、前記非線形光学材料は、ＤＡＳＴ結晶（４−Ｎ，Ｎ−ｄｉｍｅｔｈｙｌａｍｉｎｏ−４−Ｎ’−ｍｅｔｈｙｌ−ｓｔｙｌｂａｚｏｌｉｕｍ ｔｏｓｙｌａｔｅ）、ＭＮＡ（２−ｍｅｔｈｙｌ−４−ｎｉｔｒｏａｎｉｌｉｎｅ）、ＬｉＮｂＯ３、ＫＴＰ、ＧａＡｓ、ＬｉＩＯ、ＧａＳｅ、ＧａＰ、ＧａＮ、ＺｎＳｅ、ＺｎＴｅ、又はＺＧＰである。 The non-linear optical material includes DAST crystal (4-N, N-dimethylamino-4-N′-methyl-stylbazolium tosylate), MNA (2-methyl-4-nitroaniline), LiNbO 3 , KTP, GaAs, LiIO, GaSe, GaP, GaN, ZnSe, ZnTe, or ZGP.

また、前記被測定物が充填され、前記中空伝送管とテラヘルツ波検出器との間に、中空伝送管に近接して同軸に位置決めされる中空試料管を備え、該中空試料管は中赤外乃至、遠赤外伝搬用の可撓性の中空ファイバの両端がテラヘルツ波を通し水分を通さない不透過膜で密閉されている。   A hollow sample tube filled with the object to be measured and positioned coaxially in proximity to the hollow transmission tube between the hollow transmission tube and the terahertz wave detector; Or the both ends of the flexible hollow fiber for far-infrared propagation are sealed with an impervious film that transmits terahertz waves and does not allow moisture to pass.

前記中空伝送管と平行な回転中心軸と、該回転中心軸から一定の半径を隔て周方向に間隔を隔て複数の前記中空試料管を収容する複数の中空貫通穴とを有する試料回転台を備え、該試料回転台を回転中心軸を中心に一定の角度ピッチで旋回させて、複数の前記中空試料管を順次中空伝送管とテラヘルツ波検出器との間に同軸に位置決めする、ことが好ましい。   A sample turntable having a rotation center axis parallel to the hollow transmission tube and a plurality of hollow through holes for receiving the plurality of hollow sample tubes spaced apart from the rotation center axis by a certain radius in the circumferential direction. It is preferable that the sample turntable is turned at a constant angular pitch around the rotation center axis, and the plurality of hollow sample tubes are sequentially positioned coaxially between the hollow transmission tube and the terahertz wave detector.

前記中空伝送管の出射端側に位置し中空伝送管と平行に複数の中空試料管を位置決めする試料移動台を備え、該試料移動台が順次スライドして、複数の前記中空試料管を順次中空伝送管とテラヘルツ波検出器との間に同軸に位置決めする、ことが好ましい。   A sample moving table is provided on the emission end side of the hollow transmission tube and positions a plurality of hollow sample tubes in parallel with the hollow transmission tube, and the sample moving table slides sequentially to sequentially hollow the plurality of hollow sample tubes. Preferably, it is positioned coaxially between the transmission tube and the terahertz wave detector.

また本発明によれば、異なる２波長の光から非線形光学材料を用いてそれらの差周波数分に相当するテラヘルツ波を発生させ、
可撓性の前記中空伝送管を用いて発生したテラヘルツ波を入射端面から出射端面まで伝送し、
出射端面から出射したテラヘルツ波を被測定物に照射し、
該被測定物を透過または反射したテラヘルツ波の強度を計測する、ことを特徴とするテラヘルツ波分光計測方法が提供される。 Further, according to the present invention, a terahertz wave corresponding to the difference frequency between the two different wavelengths of light using a nonlinear optical material is generated,
Transmits the terahertz wave generated using the flexible hollow transmission tube from the incident end face to the outgoing end face,
Irradiate the object to be measured with terahertz waves emitted from the emission end face,
There is provided a terahertz wave spectroscopic measurement method characterized by measuring the intensity of a terahertz wave transmitted or reflected by the object to be measured.

本発明の好ましい実施形態によれば、前記可撓性の中空伝送管を人又は動物の体内に挿入して、体内の測定対象部位を２次元で分光計測イメージングする。   According to a preferred embodiment of the present invention, the flexible hollow transmission tube is inserted into a human or animal body, and a measurement target site in the body is subjected to spectroscopic imaging in two dimensions.

また、前記可撓性の中空伝送管を人又は動物の体内に挿入して、体内の測定対象物質を吸引して中空伝送管内に充填し、分光計測する。   Further, the flexible hollow transmission tube is inserted into a human or animal body, the substance to be measured in the body is sucked and filled into the hollow transmission tube, and spectroscopic measurement is performed.

また、前記可撓性の中空伝送管の出射端部を固定し、測定対象物を２次元的に移動させて、分光計測する、ことが好ましい。   Moreover, it is preferable to perform spectroscopic measurement by fixing the emitting end of the flexible hollow transmission tube and moving the measurement object two-dimensionally.

上記本発明の装置及び方法によれば、２波長光源と非線形光学材料とにより、異なる２波長の光から光差周波発生（ＤＦＧ）によりそれらの差周波数分に相当するテラヘルツ波を発生するので、２波長の各々を可変波長にすることにより、所望の周波数のテラヘルツ波を容易に発生させることができる。   According to the apparatus and method of the present invention, the two-wavelength light source and the nonlinear optical material generate terahertz waves corresponding to the difference frequency by light difference frequency generation (DFG) from two different wavelengths of light. By making each of the two wavelengths variable, it is possible to easily generate a terahertz wave having a desired frequency.

また、可撓性の細長い中空伝送管の入射端面が非線形光学材料に密着又は近接しており、この中空伝送管は、中赤外乃至、遠赤外伝搬用の中空形状の可撓性のファイバであり、両端がテラヘルツ波を通し水分を通さないように密閉され、内部にテラヘルツ波の吸収の少ないガスが密封または真空状態にされているので、有機非線形光学材料で発生したテラヘルツ波を出射端面まで少ない損失で伝送することができる。   The incident end face of the flexible elongated hollow transmission tube is in close contact with or close to the nonlinear optical material. This hollow transmission tube is a hollow flexible fiber for mid-infrared to far-infrared propagation. Since both ends are sealed so that no water can pass through the terahertz wave, and the gas that absorbs less terahertz wave is sealed or vacuumed, the terahertz wave generated by the organic nonlinear optical material is emitted. Can be transmitted with little loss.

従って本発明によれば、所望の周波数のテラヘルツ波を発生させ、これを低損失で所望の部位まで効率よく伝搬させて、被測定物を分光計測することができる。   Therefore, according to the present invention, a terahertz wave having a desired frequency can be generated and propagated efficiently to a desired site with low loss, and the object to be measured can be spectroscopically measured.

以下、本発明の好ましい実施形態を図面を参照して説明する。なお、各図において、共通する部分には同一の符号を付し重複した説明を省略する。   Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

図１は、本発明によるテラヘルツ波分光計測装置の第１実施形態図である。この図において、本発明のテラヘルツ波分光計測装置１０は、２波長光源１２、非線形光学材料１４、可撓性の細長い中空伝送管１６、及びテラヘルツ波検出器２０を備える。   FIG. 1 is a diagram showing a first embodiment of a terahertz wave spectrometer according to the present invention. In this figure, a terahertz wave spectrometer 10 of the present invention includes a two-wavelength light source 12, a nonlinear optical material 14, a flexible elongated hollow transmission tube 16, and a terahertz wave detector 20.

２波長光源１２は、異なる２波長の光を出射する。
この例において、２波長光源１２は、２つのバルクＫＴＰ結晶１２ａ，１２ｂ、ミラーＭ１，Ｍ２，Ｍ３、及びレーザ発振器１３からなる２波長光パラメトリック発振器であり、波長λ１、λ２の２波長のレーザ光１，２を出射する。このうち、波長λ１は例えば１２５０〜１６５０ｎｍで可変とし、折り返し配置にした２つのＫＴＰ結晶１２ａ，１２ｂの角度をガルバノスキャナで制御することによりλ２の波長を所望のテラヘルツ周波数に合わせて１２５０〜１６５０ｎｍで可変できるようになっている。
この構成により、０．０１ＴＨｚの間隔でテラヘルツ周波数を連続的又はパルス的に発生させることができる。
なお本発明は異なる２波長の光１，２を出射できる限りで、この構成に限定されない。 The two-wavelength light source 12 emits light having two different wavelengths.
In this example, the two-wavelength light source 12 is a two-wavelength optical parametric oscillator composed of two bulk KTP crystals 12a and 12b, mirrors M1, M2, and M3, and a laser oscillator 13, and has two wavelengths λ 1 and λ 2 . Laser beams 1 and 2 are emitted. Of these, the wavelength λ 1 is variable from 1250 to 1650 nm, for example, and the angle of the two KTP crystals 12a and 12b in the folded arrangement is controlled by a galvano scanner, so that the wavelength of λ 2 matches the desired terahertz frequency and 1250 It can be varied at 1650 nm.
With this configuration, terahertz frequencies can be generated continuously or in pulses at intervals of 0.01 THz.
The present invention is not limited to this configuration as long as it can emit light 1 and 2 having two different wavelengths.

図１において、２波長光源１２からの波長λ１、λ２の２波長のレーザ光１，２は、ミラーＭ４，Ｍ５とレンズＬを介して非線形光学材料１４の表面に対し垂直に入射する。なお、本発明において、ミラーＭ４，Ｍ５とレンズＬは必須ではなく、これらを後述するように光ファイバに置き換えることができ、あるいは省略することもできる。 In FIG. 1, two-wavelength laser beams 1 and 2 with wavelengths λ 1 and λ 2 from a two-wavelength light source 12 are perpendicularly incident on the surface of the nonlinear optical material 14 via mirrors M4 and M5 and a lens L. In the present invention, the mirrors M4 and M5 and the lens L are not essential, and these can be replaced with optical fibers as will be described later, or may be omitted.

非線形光学材料１４は、２波長λ１、λ２の光１，２から光差周波発生（ＤＦＧ）によりそれらの差周波数分に相当するテラヘルツ波３を発生する。
非線形光学材料１４は、ＤＡＳＴ結晶（４−Ｎ，Ｎ−ｄｉｍｅｔｈｙｌａｍｉｎｏ−４−Ｎ’−ｍｅｔｈｙｌ−ｓｔｙｌｂａｚｏｌｉｕｍ ｔｏｓｙｌａｔｅ）、ＭＮＡ（２−ｍｅｔｈｙｌ−４−ｎｉｔｒｏａｎｉｌｉｎｅ）、ＬｉＮｂＯ３、ＫＴＰ、ＬｉＩＯ、ＧａＳｅ、ＧａＰ、ＧａＮ、ＺｎＳｅ、ＺｎＴｅ、またはＺＧＰが好ましく、特にＤＡＳＴ結晶が好ましい。 The nonlinear optical material 14 generates a terahertz wave 3 corresponding to the difference frequency by light difference frequency generation (DFG) from the light 1 and 2 of two wavelengths λ 1 and λ 2 .
Non-linear optical material 14 includes DAST crystal (4-N, N-dimethylamino-4-N′-methyl-stylazol tosylate), MNA (2-methyl-4-nitroaniline), LiNbO 3 , KTP, LiIO, GaSe, GaP, GaN, ZnSe, ZnTe, or ZGP is preferable, and a DAST crystal is particularly preferable.

ＤＡＳＴ結晶は、ＤＡＳＴの飽和エタノール溶液を冷却する再結晶法で約２ｃｍ角、厚さ１ｍｍ以上の結晶が製造可能である。この矩形平板面上に分子の分極方向（ａ軸）を有し、外部からａ軸偏光の励起電界を印加すると分極波が生じ、非線形光学効果から励起電界と異なる周波数の光が発生する。従って、このＤＡＳＴ結晶を広帯域テラヘルツ帯の発生に用いることができる。   The DAST crystal can be produced by a recrystallization method in which a saturated ethanol solution of DAST is cooled, and a crystal having a thickness of about 2 cm square and a thickness of 1 mm or more can be produced. This rectangular flat surface has a molecular polarization direction (a-axis). When an a-axis polarized excitation electric field is applied from the outside, a polarization wave is generated, and light having a frequency different from that of the excitation electric field is generated due to a nonlinear optical effect. Therefore, this DAST crystal can be used to generate a broadband terahertz band.

可撓性の細長い中空伝送管１６は、可撓性の中赤外乃至、遠赤外伝搬用の中空ファイバである。例えば、内側に金属を成膜した金属中空ファイバや、ＰＶＤＦ（Ｐｏｌｙｖｉｎｙｌｉｄｅｎｅ Ｆｌｕｏｒｉｄｅ）製のＰＶＤＦ中空ファイバなどである。   The flexible elongated hollow transmission tube 16 is a flexible mid-infrared to far-infrared propagation hollow fiber. For example, a metal hollow fiber having a metal film formed inside, a PVDF hollow fiber made of PVDF (Polyvinylidene Fluoride), and the like.

中空伝送管１６は、非線形光学材料１４に入射端面１６ａが密着又は近接し、発生したテラヘルツ波３を出射端面１６ｂまで伝送する。非線形光学材料１４と入射端面１６ａの間隔は、皆無又は短いほど好ましい。   In the hollow transmission tube 16, the incident end face 16a is in close contact with or close to the nonlinear optical material 14, and the generated terahertz wave 3 is transmitted to the exit end face 16b. The distance between the nonlinear optical material 14 and the incident end face 16a is preferably zero or short.

また、中空伝送管１６の両端はテラヘルツ波を通し水分を通さないように不透過膜で密閉され、内部にテラヘルツ波の吸収の少ないガスが密封または真空状態にされている。この不透過膜には、市販のラップおよびポリシートを用いることができる。また、不透過膜以外のテラヘルツ波を通す部材（光学素子や非線形光学材料）で密封してもよい。
また、テラヘルツ波の吸収の少ないガスとして、乾燥空気、窒素ガス、アルゴンガス、ヘリウムガス、等を用いることができる。 Further, both ends of the hollow transmission tube 16 are sealed with an impermeable film so as to prevent the passage of moisture through the terahertz wave, and a gas with little absorption of the terahertz wave is sealed or vacuumed inside. Commercially available wraps and polysheets can be used for the impermeable membrane. Moreover, you may seal with the members (optical element or nonlinear optical material) which permeate | transmit terahertz waves other than an impervious film.
Further, dry air, nitrogen gas, argon gas, helium gas, or the like can be used as a gas with less absorption of terahertz waves.

１８ａ，１８ｂは、出射端面１６ｂから出射したテラヘルツ波３を反射して伝搬路を制御し、被測定物４に照射する方向にビームを制御する。
１８ａ，１８ｂは、この例では凹面鏡であるが、ビーム形状を制御する小型レンズであってもよいが、これを省略してもよい。また、１７は、テラヘルツ波以外の光をカットするローパスフィルタであるが、これを省略してもよい。 18 a and 18 b reflect the terahertz wave 3 emitted from the emission end face 16 b to control the propagation path, and control the beam in the direction of irradiating the DUT 4.
Although 18a and 18b are concave mirrors in this example, they may be small lenses that control the beam shape, but may be omitted. Reference numeral 17 denotes a low-pass filter that cuts light other than the terahertz wave, but this may be omitted.

テラヘルツ波検出器２０は、例えばＳｉボロメータであり、被測定物４を透過し凹面鏡１９で反射集光されたテラヘルツ波３の強度を計測する。   The terahertz wave detector 20 is, for example, a Si bolometer, and measures the intensity of the terahertz wave 3 that has been transmitted through the DUT 4 and reflected and collected by the concave mirror 19.

なお、図１において、１１は制御記録装置（例えばＰＣ）であり、２波長光源１２を制御し、計測されたテラヘルツ波３の強度を記録するとともに、必要な解析を行う。また９は表示装置であり、計測結果及び解析結果を表示するようになっている。   In FIG. 1, reference numeral 11 denotes a control recording device (for example, PC), which controls the two-wavelength light source 12 to record the measured intensity of the terahertz wave 3 and perform necessary analysis. Reference numeral 9 denotes a display device that displays measurement results and analysis results.

上述した装置を用いて、本発明によるテラヘルツ波分光計測方法によれば、異なる２波長の光１，２から非線形光学材料１４を用いてそれらの差周波数分に相当するテラヘルツ波３を発生させ、可撓性の中赤外乃至、遠赤外伝搬用の中空伝送管１６を用いて発生したテラヘルツ波３を入射端面１６ａから出射端面１６ｂまで伝送し、出射端面１６ｂから出射したテラヘルツ波３を被測定物４に照射し、被測定物４を透過したテラヘルツ波３の強度を計測する。   Using the above-described apparatus, according to the terahertz wave spectroscopic measurement method according to the present invention, the terahertz wave 3 corresponding to the difference frequency between them is generated using the nonlinear optical material 14 from the light 1 and 2 having two different wavelengths, The terahertz wave 3 generated using the flexible mid-infrared to far-infrared propagation hollow transmission tube 16 is transmitted from the incident end face 16a to the exit end face 16b, and the terahertz wave 3 emitted from the exit end face 16b is transmitted. The intensity of the terahertz wave 3 that irradiates the measurement object 4 and passes through the measurement object 4 is measured.

図２は、本発明によるテラヘルツ波分光計測装置の第２実施形態図であり、（Ａ）は全体構成図、（Ｂ）（Ｃ）は中空伝送管の断面図、（Ｄ）はその部分斜視図である。
図２Ａにおいて、本発明のテラヘルツ波分光計測装置１０は、２波長光源１２、非線形光学材料１４、中空伝送管１６、中空試料管２２及びテラヘルツ波検出器２０を備える。
図２Ｂ、図２Ｄにおいて、非線形光学材料１４は、中空伝送管１６の入射端部内に気密に取り付けられている。光学系１８は、ビーム形状を制御する小型レンズであり、必要に応じて取り付けることができ、中空伝送管１６の出射端部内に気密に取り付けられている。なお、小型レンズを出射端１６ｂの外側に設けてもよい。
図２Ｃにおいて、１７ａ，１７ｂ，１７ｃは、密封のためのＴＨｚ帯透過性膜（例えばラップ、フィルムなど）である。 FIG. 2 is a diagram showing a second embodiment of the terahertz wave spectrometer according to the present invention, where (A) is an overall configuration diagram, (B) and (C) are cross-sectional views of a hollow transmission tube, and (D) is a partial perspective view thereof. FIG.
2A, the terahertz wave spectrometer 10 of the present invention includes a two-wavelength light source 12, a nonlinear optical material 14, a hollow transmission tube 16, a hollow sample tube 22, and a terahertz wave detector 20.
2B and 2D, the nonlinear optical material 14 is hermetically attached in the incident end portion of the hollow transmission tube 16. The optical system 18 is a small lens that controls the beam shape, and can be attached as necessary. The optical system 18 is airtightly attached to the exit end of the hollow transmission tube 16. A small lens may be provided outside the emitting end 16b.
In FIG. 2C, 17a, 17b, 17c are THz band permeable membranes (for example, wraps, films, etc.) for sealing.

中空試料管２２は、可撓性の中赤外乃至、遠赤外伝搬用の中空ファイバの両端がテラヘルツ波を通し水分を通さない不透過膜で密閉されている。なお中空試料管２２には、中空伝送管１６と同一のものを用いることが好ましい。
また、中空試料管２２は、内部に被測定物が充填され、かつ中空伝送管１６とテラヘルツ波検出器２０との間に、中空伝送管２２に近接して同軸に位置決めされる。内部に充填される被測定物としては、気体、粉体、ＤＮＡ、菌等を封入することができる。
その他の構成は図１と同様である。 In the hollow sample tube 22, both ends of a flexible mid-infrared to far-infrared propagation hollow fiber are sealed with an impervious membrane that does not allow moisture to pass through terahertz waves. The hollow sample tube 22 is preferably the same as the hollow transmission tube 16.
The hollow sample tube 22 is filled with an object to be measured, and is positioned coaxially between the hollow transmission tube 16 and the terahertz wave detector 20 in proximity to the hollow transmission tube 22. Gas, powder, DNA, bacteria, etc. can be enclosed as the measurement object filled inside.
Other configurations are the same as those in FIG.

上述した構成により、非線形光学材料１４で発生したテラヘルツ波３を中空伝送管１６で低損失で伝送し、中空試料管２２に入射させ、中空試料管２２内において被測定物（気体、粉体、ＤＮＡ、菌等）に照射しながら低損失で伝送し、テラヘルツ波検出器２０で被測定物を透過したテラヘルツ波の強度を計測することができる。   With the above-described configuration, the terahertz wave 3 generated in the nonlinear optical material 14 is transmitted through the hollow transmission tube 16 with low loss, is incident on the hollow sample tube 22, and the object to be measured (gas, powder, The intensity of the terahertz wave transmitted through the object to be measured can be measured by the terahertz wave detector 20 while being transmitted with low loss while irradiating DNA, bacteria, or the like.

図３は、本発明によるテラヘルツ波分光計測装置の第３実施形態図である。
図３Ａにおいて、本発明のテラヘルツ波分光計測装置は、図２の構成に加えてさらに試料回転台２４を備える。
試料回転台２４は、中空伝送管１６と平行な回転中心軸２４ａと、回転中心軸２４ａから一定の半径を隔て周方向に間隔を隔てた複数の中空貫通穴２４ｂとを有する。中空貫通穴２４ｂは、中空試料管２２を中空伝送管１６と平行に収容するようになっている。
この構成により、試料回転台２４を回転中心軸２４ａを中心に一定の角度ピッチで旋回させて、複数の中空試料管２２を順次中空伝送管１６とテラヘルツ波検出器２０（図示せず）との間に同軸に位置決めすることができ、多数の中空試料管２２の分光計測を効率よく行うことができる。 FIG. 3 is a diagram showing a third embodiment of the terahertz wave spectrometer according to the present invention.
3A, the terahertz wave spectroscopic measurement apparatus of the present invention further includes a sample turntable 24 in addition to the configuration of FIG.
The sample turntable 24 has a rotation center shaft 24a parallel to the hollow transmission tube 16, and a plurality of hollow through holes 24b spaced apart from the rotation center shaft 24a in the circumferential direction by a certain radius. The hollow through hole 24 b is configured to accommodate the hollow sample tube 22 in parallel with the hollow transmission tube 16.
With this configuration, the sample turntable 24 is swung around the rotation center axis 24a at a constant angular pitch, and a plurality of hollow sample tubes 22 are sequentially connected to the hollow transmission tube 16 and the terahertz wave detector 20 (not shown). It can be positioned coaxially between them, and the spectroscopic measurement of a large number of hollow sample tubes 22 can be performed efficiently.

図３Ｂにおいて、本発明のテラヘルツ波分光計測装置は、図２の構成に加えてさらに試料移動台２５を備える。
試料移動台２５は、中空伝送管１６の出射端側に位置し中空伝送管１６と平行に複数の中空試料管２２を位置決めする。またこの試料移動台２５が順次スライドして、複数の中空試料管２２を順次中空伝送管１６とテラヘルツ波検出器との間に同軸に位置決めするようになっている。
この構成により、多数の中空試料管２２の分光計測を効率よく行うことができる。 In FIG. 3B, the terahertz wave spectrometer of the present invention further includes a sample moving table 25 in addition to the configuration of FIG.
The sample moving table 25 is positioned on the emission end side of the hollow transmission tube 16 and positions the plurality of hollow sample tubes 22 in parallel with the hollow transmission tube 16. Further, the sample moving table 25 slides sequentially so that the plurality of hollow sample tubes 22 are sequentially positioned coaxially between the hollow transmission tube 16 and the terahertz wave detector.
With this configuration, it is possible to efficiently perform spectroscopic measurement of a large number of hollow sample tubes 22.

図４は、中空伝送管１６及び中空試料管２２におけるテラヘルツ波３の伝搬模式図である。
図４Ａに示すように、中空伝送管１６及び中空試料管２２（後述の例では銀中空ファイバ）の内部でテラヘルツ波３は反射しながら伝搬する。粉体などを分光計測する場合、反射点に存在する物質によって特定の周波数のみが吸収され、そのスペクトル構造が明らかになる。
伝搬角θは、数１の式（１）で表される。（５ＴＨｚ、ＴＥ１１モードは８８°）
また、反射回数ｎは伝搬角θに依存し、数１の式（２）で表される。Ｌは中空伝送管１６及び中空試料管２２の長さであり、ａは中空伝送管１６及び中空試料管２２の内径であり、ｋ０は自由空間中でのテラヘルツ波の波数であり、ｕ∞はベッセル関数の根を示す。 FIG. 4 is a schematic diagram of propagation of the terahertz wave 3 in the hollow transmission tube 16 and the hollow sample tube 22.
As shown in FIG. 4A, the terahertz wave 3 propagates while reflecting inside the hollow transmission tube 16 and the hollow sample tube 22 (silver hollow fiber in the example described later). When spectrally measuring powder or the like, only a specific frequency is absorbed by the substance present at the reflection point, and the spectral structure becomes clear.
The propagation angle θ is expressed by Equation (1) in Equation 1. (5 THz, TE 11 mode is 88 °)
Further, the number of reflections n depends on the propagation angle θ and is expressed by Equation (2) in Equation 1. L is the length of the hollow transmission tube 16 and a hollow sample tube 22, a is an inner diameter of the hollow transmission tube 16 and a hollow sample tube 22, k 0 is the wave number of the terahertz wave in a free space, u ∞ Indicates the root of the Bessel function.

Figure 2008241340
Figure 2008241340

図４Ｂは、テラヘルツ波３の周波数と反射回数の関係図である。この図において、中空伝送管１６及び中空試料管２２として後述する銀中空ファイバ（内径１ｍｍ）を用い、１０ｃｍ長と５ｃｍ長のファイバに対し、主要伝搬モードのＴＥ１１における反射回数を示している。
この図から、例えば、１０ｃｍ長の場合に５ＴＨｚのテラヘルツ波３は約４回反射することがわかる。銀中空ファイバ（内径１ｍｍ）の内容積は８０μＬであることから、非常に微量の試料を用いて、粉体を含む被測定物の分光計測ができることがわかる。
なお、上記長さは一例であり、必要に応じて、任意の長さの銀中空ファイバを用いることができる。 FIG. 4B is a relationship diagram between the frequency of the terahertz wave 3 and the number of reflections. In this figure, silver hollow fibers (inner diameter: 1 mm), which will be described later, are used as the hollow transmission tube 16 and the hollow sample tube 22, and the number of reflections in TE 11 in the main propagation mode is shown for fibers of 10 cm length and 5 cm length.
From this figure, it can be seen that, for example, when the length is 10 cm, the 5 THz terahertz wave 3 is reflected approximately four times. Since the inner volume of the silver hollow fiber (inner diameter: 1 mm) is 80 μL, it can be seen that spectroscopic measurement of an object to be measured including powder can be performed using a very small amount of sample.
In addition, the said length is an example and can use the silver hollow fiber of arbitrary lengths as needed.

図５は、本発明によるテラヘルツ波分光計測装置の第４実施形態図である。この図において、本発明のテラヘルツ波分光計測装置１０の２波長光源１２は、可変波長の第１レーザ光１を発振する第１レーザ発振装置３２と、可変波長の第２レーザ光２を発振する第２レーザ発振装置３４と、第１レーザ光１と第２レーザ光２を同一光路に結合する方向性結合器３６と、同一光路の第１レーザ光１と第２レーザ光２を非線形光学材料まで導く可撓性の光ファイバ３８とを有する。３０は、第１レーザ発振装置３２と第２レーザ発振装置３４を制御する制御装置（例えばＰＣ）である。
中空伝送管１６は、光ファイバ３８の先端部に取り付けられ、非線形光学材料１４（図示せず）は、中空伝送管１６の入射端面に密着又は近接、ないしは挿入して取り付けられている。
この構成により、この図に示すように、可撓性の中空伝送管１６を人又は動物５の体内に挿入して、体内の測定対象部位（この例では胃）を２次元で分光計測イメージングすることができる。
なお、この場合、テラヘルツ波検出器は、中空伝送管１６の出射端面に対峙して一体化するか、人又は動物５の外部で計測するのがよい。 FIG. 5 is a diagram of a fourth embodiment of the terahertz wave spectrometer according to the present invention. In this figure, a two-wavelength light source 12 of a terahertz wave spectrometer 10 according to the present invention oscillates a first laser oscillator 32 that oscillates a first laser beam 1 having a variable wavelength and a second laser beam 2 that has a variable wavelength. A second laser oscillation device 34; a directional coupler 36 for coupling the first laser beam 1 and the second laser beam 2 into the same optical path; and the first laser beam 1 and the second laser beam 2 in the same optical path And a flexible optical fiber 38 that leads to Reference numeral 30 denotes a control device (for example, PC) that controls the first laser oscillation device 32 and the second laser oscillation device 34.
The hollow transmission tube 16 is attached to the distal end portion of the optical fiber 38, and the nonlinear optical material 14 (not shown) is attached to the incident end surface of the hollow transmission tube 16 in close contact with or close to or inserted therein.
With this configuration, as shown in this figure, a flexible hollow transmission tube 16 is inserted into the body of a human or animal 5 to spectroscopically measure and image a region to be measured (the stomach in this example) in the body. be able to.
In this case, the terahertz wave detector is preferably integrated with the emission end face of the hollow transmission tube 16 or measured outside the human or animal 5.

また、可撓性の中空伝送管１６（又は中空試料管２２）を人又は動物５の体内に挿入して、体内の測定対象物質を吸引して中空伝送管１６（又は中空試料管２２）内に充填し、これを上述した装置を用いて分光計測してもよい。   Further, the flexible hollow transmission tube 16 (or the hollow sample tube 22) is inserted into the body of a human or animal 5, and the substance to be measured in the body is sucked into the hollow transmission tube 16 (or the hollow sample tube 22). And may be spectroscopically measured using the apparatus described above.

上述した装置及び方法により、人又は動物５の体内の測定対象部位をテラヘルツ波３を用いて容易に分光計測することができる。   By using the above-described apparatus and method, it is possible to easily perform spectroscopic measurement of a measurement target site in a human or animal 5 using the terahertz wave 3.

図６は、本発明によるテラヘルツ波分光計測装置の第５実施形態図である。この図において、本発明のテラヘルツ波分光計測装置１０は、第４実施形態の装置に更に２次元ステージ４０を備え、可撓性の中空伝送管１６の出射端部を固定し、測定対象物４を２次元的に移動させて、分光計測する。   FIG. 6 is a diagram showing a fifth embodiment of the terahertz wave spectrometer according to the present invention. In this figure, a terahertz wave spectroscopic measurement apparatus 10 of the present invention further includes a two-dimensional stage 40 in the apparatus of the fourth embodiment, fixes the emission end of a flexible hollow transmission tube 16, and measures the measurement object 4. Is moved in a two-dimensional manner to perform spectroscopic measurement.

この装置及び方法により、測定対象物４の２次元分光計測を容易に実施することができる。   With this apparatus and method, the two-dimensional spectroscopic measurement of the measurement object 4 can be easily performed.

以下、本発明の実施例を説明する。
図１に示した装置を用いて、中空伝送管１６によるテラヘルツ波３の伝搬特性を試験した。中空伝送管１６として、可撓性のある内径１ｍｍのガラスキャピラリ内部に銀をコーティングした銀中空ファイバを用いた。また、非線形光学材料１４として、厚さ０．８ｍｍのＤＡＳＴ結晶を長さ６ｃｍのカップリング用銀中空ファイバの端面に接するように配置して、銀中空ファイバを接続した。ａ軸偏光の１．３μｍ帯二波長光をＴＨｚ帯励起光としてｃ軸方向へ入射し、光差周波発生（ＤＦＧ）で２〜１５ＴＨｚ帯を発生させて伝搬特性の周波数依存性及び曲げの伝搬特性をＳｉボロメータで計測した。 Examples of the present invention will be described below.
The propagation characteristics of the terahertz wave 3 by the hollow transmission tube 16 were tested using the apparatus shown in FIG. As the hollow transmission tube 16, a silver hollow fiber in which silver is coated inside a flexible glass capillary having an inner diameter of 1 mm was used. Further, as the nonlinear optical material 14, a DAST crystal having a thickness of 0.8 mm was disposed so as to be in contact with an end face of a coupling silver hollow fiber having a length of 6 cm, and the silver hollow fiber was connected. A-axis polarized 1.3 μm band dual wavelength light is incident as THz band excitation light in the c-axis direction and 2-15 THz band is generated by optical difference frequency generation (DFG), and the frequency dependence of propagation characteristics and bending propagation The characteristics were measured with a Si bolometer.

図７は、長さ３０．５ｃｍ、曲げ角０°の銀中空ファイバの試験結果であり、（Ａ）はＤＡＳＴからのテラヘルツ波の出力強度、（Ｂ）は銀中空ファイバの透過特性である。
この図から２〜１５ＴＨｚのテラヘルツ波に対して急峻な吸収特性は見られず、テラヘルツ波帯で上述したデバイスへの適用ができることが確認された。 FIG. 7 shows the test results of a silver hollow fiber having a length of 30.5 cm and a bending angle of 0 °. (A) shows the output intensity of the terahertz wave from DAST, and (B) shows the transmission characteristics of the silver hollow fiber.
From this figure, it was confirmed that a steep absorption characteristic was not observed with respect to a terahertz wave of 2 to 15 THz, and that it could be applied to the above-described device in the terahertz wave band.

次に曲げ角０°の場合を１とし、曲線の円弧長さを一定として角度を変化させた試験を実施した。この場合の透過特性を図８に示す。
この図から１４．５ＴＨｚでは角度が大きくなるにつれ透過特性が低下するが、５ＴＨｚから１０ＴＨｚまでは曲げによる付加損は小さく（最大１ｄＢ程度）、十分実用化できることが確認された。 Next, a test was performed in which the bending angle was 0 ° and the angle was changed with the arc length of the curve being constant. The transmission characteristics in this case are shown in FIG.
From this figure, it is confirmed that the transmission characteristics decrease as the angle increases at 14.5 THz, but the additional loss due to bending is small (up to about 1 dB) from 5 THz to 10 THz, and it was confirmed that it can be sufficiently put into practical use.

図９は、銀中空ファイバ内に呼気を吹き入れて計測した結果であり、水と水蒸気の透過特性と比較している。
この図において、この帯域全体の包絡線は水（破線）の透過特性に近似しており、また、細かな構造は水蒸気（下端の図）のスペクトルに極似していることがわかる。
このことから、この帯域（２〜１５ＴＨｚ）で測定されるのは主として水と水蒸気であり、大気中の水蒸気による吸収が非常に大きいことがわかる。 FIG. 9 shows the results of measurement by injecting exhaled air into the silver hollow fiber, and compared with the permeation characteristics of water and water vapor.
In this figure, it can be seen that the envelope of this entire band approximates the transmission characteristics of water (dashed line), and that the fine structure resembles the spectrum of water vapor (bottom figure).
From this, it is understood that water and water vapor are mainly measured in this band (2 to 15 THz), and absorption by water vapor in the atmosphere is very large.

図１０は、銀中空ファイバ内にハイドロフルオロカーボン（ＨＦＣ）を入れて計測した結果であり、計算上の吸収ピーク（下側の縦線）と比較している。なお、この例は、ＨＦＣ−１３４ａの場合を示している。
この図から、吸収ピークの測定値と計算値がよく一致しており、ハイドロフルオロカーボンの分光計測が可能であることがわかる。なお、同様に、ＨＦＣ−１５２ａの場合にも、同様の結果が得られた。 FIG. 10 shows the result of measurement by putting hydrofluorocarbon (HFC) in the silver hollow fiber, and compares it with the calculated absorption peak (lower vertical line). This example shows the case of HFC-134a.
From this figure, it can be seen that the measured value of the absorption peak agrees well with the calculated value, and the spectroscopic measurement of hydrofluorocarbon is possible. Similarly, similar results were obtained with HFC-152a.

図１１は、銀中空ファイバ内にエタノール（ＣＨ３ＣＨ２ＯＨ）を入れて計測した結果であり、計算上の吸収ピーク（下側の縦線）と水及び水蒸気の透過特性と比較している。
この図から、６ＴＨｚ付近の吸収は水、エタノール、水蒸気の３種類の吸収特性が重なりあったような特性を示している。また、１３ＴＨｚ付近の吸収は計算値で求めた振動モードにほぼ一致し、全領域にわたるスペクトルの微細構造はわずかに含まれる水蒸気によるものと推測される。特に１３ＴＨｚでの吸収特性は水と水蒸気の影響が少なく、エタノールの検出に適しているといえる。 FIG. 11 shows the result of measurement with ethanol (CH 3 CH 2 OH) placed in a silver hollow fiber, which is compared with a calculated absorption peak (lower vertical line) and water and water vapor transmission characteristics. .
From this figure, the absorption in the vicinity of 6 THz shows characteristics such that three types of absorption characteristics of water, ethanol, and water vapor overlap. In addition, the absorption near 13 THz almost coincides with the vibration mode obtained by the calculated value, and it is estimated that the fine structure of the spectrum over the entire region is due to the slightly contained water vapor. In particular, the absorption characteristic at 13 THz is less affected by water and water vapor, and can be said to be suitable for detection of ethanol.

また、市販のラップ及びポリシートを用い、両端を封入することにより、テラヘルツ波を通し水分を通さないようにできることも試験により確認された。   Moreover, it was also confirmed by a test that a commercially available wrap and a poly sheet were used and both ends were sealed so that water could not pass through terahertz waves.

上述した本発明の装置及び方法によれば、２波長光源１２と有機非線形光学材料１４とにより、異なる２波長の光１，２から光差周波発生（ＤＦＧ）によりそれらの差周波数分に相当するテラヘルツ波３を発生するので、２波長１，２を可変波長にすることにより、所望の周波数のテラヘルツ波３を容易に発生させることができる。   According to the above-described apparatus and method of the present invention, the two-wavelength light source 12 and the organic nonlinear optical material 14 correspond to the difference frequency components of the two different-wavelength lights 1 and 2 by optical difference frequency generation (DFG). Since the terahertz wave 3 is generated, the terahertz wave 3 having a desired frequency can be easily generated by making the two wavelengths 1 and 2 variable.

また、可撓性の細長い中空伝送管１６の入射端面１６ａが非線形光学材料１４に密着又は近接しており、この中空伝送管は、可撓性の中赤外乃至、遠赤外伝搬用の中空ファイバの両端がテラヘルツ波を通し水分を通さないように密閉され、内部にテラヘルツ波の吸収の少ないガスが密封または真空状態にされているので、非線形光学材料で発生したテラヘルツ波３を出射端面まで少ない損失で伝送することができる。
従って、本発明によれば、所望の周波数のテラヘルツ波を発生させ、発生したテラヘルツ波を低損失で任意の場所まで伝搬させることが可能となり、光ファイバでＤＡＳＴ結晶へ励起光を入射するシステムの構築により、全ファイバでの測定システムの実現が可能になるという優れた効果を奏す。 The incident end face 16a of the flexible elongated hollow transmission tube 16 is in close contact with or close to the nonlinear optical material 14, and this hollow transmission tube is a flexible mid-infrared to far-infrared hollow for propagation. Since both ends of the fiber are sealed so as not to allow moisture to pass through the terahertz wave, and a gas with little terahertz wave absorption is sealed or vacuumed inside, the terahertz wave 3 generated by the nonlinear optical material is transmitted to the emission end face. It can be transmitted with little loss.
Therefore, according to the present invention, it is possible to generate a terahertz wave having a desired frequency, propagate the generated terahertz wave to an arbitrary place with low loss, and an optical fiber that makes excitation light incident on a DAST crystal. The construction has an excellent effect that a measurement system with all fibers can be realized.

なお、本発明は上述した実施例及び実施形態に限定されず、本発明の要旨を逸脱しない範囲で種々変更できることは勿論である。   In addition, this invention is not limited to the Example and embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.

本発明によるテラヘルツ波分光計測装置の第１実施形態図である。1 is a first embodiment diagram of a terahertz wave spectrometer according to the present invention. FIG. 本発明によるテラヘルツ波分光計測装置の第２実施形態図である。It is a 2nd embodiment figure of a terahertz wave spectroscopic measuring device by the present invention. 本発明によるテラヘルツ波分光計測装置の第３実施形態図である。It is a 3rd embodiment figure of a terahertz wave spectroscopic measuring device by the present invention. 中空伝送管及び中空試料管におけるテラヘルツ波の伝搬模式図である。It is a propagation schematic diagram of the terahertz wave in a hollow transmission tube and a hollow sample tube. 本発明によるテラヘルツ波分光計測装置の第４実施形態図である。It is a 4th embodiment figure of a terahertz wave spectroscopic measuring device by the present invention. 本発明によるテラヘルツ波分光計測装置の第５実施形態図である。It is a 5th embodiment figure of a terahertz wave spectroscopic measuring device by the present invention. 長さ３０．５ｃｍ、曲げ角０°の銀中空ファイバの試験結果である。It is a test result of a silver hollow fiber having a length of 30.5 cm and a bending angle of 0 °. 曲線の円弧長さを一定として角度を変化させた試験結果である。It is a test result in which the angle is changed while keeping the arc length of the curve constant. 銀中空ファイバ内に呼気を吹き入れて計測した結果である。It is the result of having measured exhaled breath into the silver hollow fiber. 銀中空ファイバ内にハイドロフルオロカーボン（ＨＦＣ）を入れて計測した結果である。It is the result of putting and measuring hydrofluorocarbon (HFC) in a silver hollow fiber. 銀中空ファイバ内にエタノール（ＣＨ３ＣＨ２ＯＨ）を入れて計測した結果である。It is the result of putting ethanol (CH 3 CH 2 OH) in the silver hollow fiber and measuring it. 特許文献１の集積モジュールの模式図である。10 is a schematic diagram of an integrated module of Patent Document 1. FIG. 特許文献２のテラヘルツ波発生システムの模式図である。1 is a schematic diagram of a terahertz wave generation system disclosed in Patent Document 2. FIG. 非特許文献１の試験装置の模式図である。1 is a schematic diagram of a test apparatus of Non-Patent Document 1.

符号の説明Explanation of symbols

・ レーザ光、３ テラヘルツ波、４ 被測定物、５ 人又は動物、
１０ テラヘルツ波分光計測装置、１１ 制御記録装置（ＰＣ）、
１２ ２波長光源、１２ａ，１２ｂ バルクＫＴＰ結晶、
１３ レーザ発振器、１４ 有機非線形光学材料、
１６ 中空伝送管、１６ａ 入射端面、１６ｂ 出射端面、
１８ 光学系、１８ａ，１８ｂ 凹面鏡、２０ テラヘルツ波検出器、
２２ 中空試料管、２４ 試料回転台、
２４ａ 回転中心軸、２４ｂ 中空貫通穴、
２５ 試料移動台、３０ 制御装置（ＰＣ）、
３２ 第１レーザ発振装置、３４ 第２レーザ発振装置、
３６ 方向性結合器、３８ 光ファイバ、４０ ２次元ステージ ・ Laser beam, 3 terahertz wave, 4 object to be measured, 5 persons or animals,
10 terahertz spectrometer, 11 control recording device (PC),
12 two-wavelength light source, 12a, 12b bulk KTP crystal,
13 laser oscillator, 14 organic nonlinear optical material,
16 hollow transmission tube, 16a entrance end face, 16b exit end face,
18 optical system, 18a, 18b concave mirror, 20 terahertz wave detector,
22 hollow sample tubes, 24 sample turntables,
24a rotation center shaft, 24b hollow through hole,
25 Sample moving table, 30 controller (PC),
32 1st laser oscillator, 34 2nd laser oscillator,
36 directional coupler, 38 optical fiber, 40 two-dimensional stage

Claims (11)

異なる２波長の光を出射する２波長光源と、
前記２波長の光から光差周波発生によりそれらの差周波数分に相当するテラヘルツ波を発生する非線形光学材料と、
該非線形光学材料が入射端面に密着又は近接又は挿入され、発生したテラヘルツ波を出射端面まで内部を伝送する可撓性の細長い中空伝送管と、
該被測定物を透過したテラヘルツ波の強度を計測するテラヘルツ波検出器と、を備え、
前記中空伝送管は、中赤外乃至、遠赤外伝搬用の可撓性の中空ファイバである、ことを特徴とするテラヘルツ波分光計測装置。 A two-wavelength light source that emits light of two different wavelengths;
A non-linear optical material that generates terahertz waves corresponding to the difference frequency from the light of the two wavelengths by light difference frequency generation;
A flexible elongated hollow transmission tube in which the nonlinear optical material is closely contacted or close to or inserted into the incident end face, and transmits the generated terahertz wave to the exit end face;
A terahertz wave detector for measuring the intensity of the terahertz wave transmitted through the object to be measured,
The terahertz wave spectrometer is characterized in that the hollow transmission tube is a flexible hollow fiber for propagating from mid-infrared to far-infrared. 前記中空伝送管は、中赤外乃至、遠赤外伝搬用の可撓性の中空形状のファイバであり、その両端がテラヘルツ波を通し水分を通さないように密閉され、内部にテラヘルツ波の吸収の少ないガスが密封または真空状態にされている、ことを特徴とする請求項１に記載のテラヘルツ波分光計測装置。   The hollow transmission tube is a flexible hollow fiber for mid-infrared to far-infrared propagation, and both ends of the hollow transmission tube are sealed so as not to pass moisture through terahertz waves and absorb terahertz waves inside. The terahertz wave spectroscopic measurement apparatus according to claim 1, wherein a gas with a small amount of gas is sealed or vacuumed. 前記中空伝送管は、内部に金属面を有する金属中空ファイバや、ＰＶＤＦ（ｐｏｌｙｖｉｎｙｌｉｄｅｎｅ Ｆｌｕｏｒｉｄｅ）製中空ファイバである、ことを特徴とする請求項２に記載のテラヘルツ波分光計測装置。   The terahertz wave spectrometer according to claim 2, wherein the hollow transmission tube is a metal hollow fiber having a metal surface inside or a hollow fiber made of PVDF (polyvinylidene fluoride). 前記非線形光学材料は、ＤＡＳＴ結晶（４−Ｎ，Ｎ−ｄｉｍｅｔｈｙｌａｍｉｎｏ−４−Ｎ’−ｍｅｔｈｙｌ−ｓｔｙｌｂａｚｏｌｉｕｍ ｔｏｓｙｌａｔｅ）、ＭＮＡ（２−ｍｅｔｈｙｌ−４−ｎｉｔｒｏａｎｉｌｉｎｅ）、ＬｉＮｂＯ３、ＫＴＰ、ＧａＡｓ、ＬｉＩＯ、ＧａＳｅ、ＧａＰ、ＧａＮ、ＺｎＳｅ、ＺｎＴｅ、又はＺＧＰである、ことを特徴とする請求項１に記載のテラヘルツ波分光計測装置。 The non-linear optical material includes DAST crystal (4-N, N-dimethylamino-4-N′-methyl-stylvazolium tosylate), MNA (2-methyl-4-nitroaniline), LiNbO 3 , KTP, GaAs, LiIO, GaSe, The terahertz wave spectrometer according to claim 1, wherein the terahertz wave spectrometer is GaP, GaN, ZnSe, ZnTe, or ZGP. 前記被測定物が充填され、前記中空伝送管とテラヘルツ波検出器との間に、中空伝送管に近接して同軸に位置決めされる中空試料管を備え、該中空試料管は中赤外、乃至遠赤外伝搬用の可撓性の中空ファイバの両端がテラヘルツ波を通し水分を通さない不透過膜で密閉されている、ことを特徴とする請求項１に記載のテラヘルツ波分光計測装置。   A hollow sample tube that is filled with the object to be measured and is positioned coaxially in proximity to the hollow transmission tube between the hollow transmission tube and the terahertz wave detector is provided. 2. The terahertz wave spectroscopic measurement apparatus according to claim 1, wherein both ends of the far-infrared-propagating flexible hollow fiber are sealed with an impermeable film that transmits a terahertz wave and does not allow moisture to pass. 前記中空伝送管と平行な回転中心軸と、該回転中心軸から一定の半径を隔て周方向に間隔を隔て複数の前記中空試料管を収容する複数の中空貫通穴とを有する試料回転台を備え、該試料回転台を回転中心軸を中心に一定の角度ピッチで旋回させて、複数の前記中空試料管を順次中空伝送管とテラヘルツ波検出器との間に同軸に位置決めする、ことを特徴とする請求項５に記載のテラヘルツ波分光計測装置。   A sample turntable having a rotation center axis parallel to the hollow transmission tube and a plurality of hollow through holes for receiving the plurality of hollow sample tubes spaced apart from the rotation center axis by a certain radius in the circumferential direction. And rotating the sample turntable at a constant angular pitch about the rotation center axis, and sequentially positioning the plurality of hollow sample tubes coaxially between the hollow transmission tube and the terahertz wave detector. The terahertz wave spectrometer according to claim 5. 前記中空伝送管の出射端側に位置し中空伝送管と平行に複数の中空試料管を位置決めする試料移動台を備え、該試料移動台が順次スライドして、複数の前記中空試料管を順次中空伝送管とテラヘルツ波検出器との間に同軸に位置決めする、ことを特徴とする請求項５に記載のテラヘルツ波分光計測装置。   A sample moving table is provided on the emission end side of the hollow transmission tube and positions a plurality of hollow sample tubes in parallel with the hollow transmission tube, and the sample moving table slides sequentially to sequentially hollow the plurality of hollow sample tubes. 6. The terahertz wave spectrometer according to claim 5, wherein the terahertz wave spectrometer is positioned coaxially between the transmission tube and the terahertz wave detector. 異なる２波長の光から非線形光学材料を用いてそれらの差周波数分に相当するテラヘルツ波を発生させ、
可撓性の前記中空伝送管を用いて発生したテラヘルツ波を入射端面から出射端面まで伝送し、
出射端面から出射したテラヘルツ波を被測定物に照射し、
該被測定物を透過または反射したテラヘルツ波の強度を計測する、ことを特徴とするテラヘルツ波分光計測方法。 A terahertz wave corresponding to the difference frequency between them is generated from light of two different wavelengths using a nonlinear optical material,
Transmits the terahertz wave generated using the flexible hollow transmission tube from the incident end face to the outgoing end face,
Irradiate the object to be measured with terahertz waves emitted from the emission end face,
A terahertz wave spectroscopic measurement method, comprising: measuring an intensity of a terahertz wave transmitted or reflected by the object to be measured. 前記可撓性の中空伝送管を人又は動物の体内に挿入して、体内の測定対象部位を２次元で分光計測イメージングする、ことを特徴とする請求項８に記載のテラヘルツ波分光計測方法。   The terahertz wave spectroscopic measurement method according to claim 8, wherein the flexible hollow transmission tube is inserted into a human or animal body, and a region to be measured is spectroscopically imaged in two dimensions. 前記可撓性の中空伝送管を人又は動物の体内に挿入して、体内の測定対象物質を吸引して中空伝送管内に充填し、分光計測することを特徴とする請求項８に記載のテラヘルツ波分光計測方法。   The terahertz according to claim 8, wherein the flexible hollow transmission tube is inserted into a human or animal body, a substance to be measured in the body is sucked into the hollow transmission tube, and spectroscopic measurement is performed. Wave spectroscopy measurement method. 前記可撓性の中空伝送管の出射端部を固定し、測定対象物を２次元的に移動させて、分光計測することを特徴とする請求項８に記載のテラヘルツ波分光計測方法。   The terahertz wave spectroscopic measurement method according to claim 8, wherein spectroscopic measurement is performed by fixing an emission end of the flexible hollow transmission tube and moving a measurement object two-dimensionally.
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