TWI225948B - Single-fanout cascaded grating quasi-phase-matched nonlinear optical crystal and wavelength conversion and tunable laser system using the same - Google Patents
Single-fanout cascaded grating quasi-phase-matched nonlinear optical crystal and wavelength conversion and tunable laser system using the same Download PDFInfo
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1225948 五、發明說明（1) 發明所屬之技術領域 本案係有關非線性光學單一晶體之光柵設計’特別 是關於准相也匹配（Quasi-Phase-Matching; QPM)非線性 光學單一晶體（monolithic crystal)之線性與扇形串連 光柵設計及利用該晶體作為頻率轉換器（f r e q u e n c y converter)之雷射產生裝置。 先前技術1225948 V. Description of the invention (1) The technical field to which the invention belongs This invention relates to the design of gratings for nonlinear optical single crystals, especially regarding quasi-phase-matching (QPM) nonlinear optical single crystals The linear and fan-shaped serial grating design and the laser generating device using the crystal as a frequency converter. Prior art
隨著雷射科技之快速演進，各式各樣的雷射已被廣 泛地應用於不同的領域。傳統上大部分雷射光是利用電 子或載子在不同能階間的躍遷而發射固定波長或頻率的 同調電磁輻射。以固態雷射為例，固態雷射由於系統簡 單輕巧，再加上近年光電材料科學的蓬勃發展，' ^各二 波長與功率的固態雷射持續被開發，而成為各類 ^ 中的主流。半導體雷射是其中最典型的例子。半 射因為體積小、操作耗電功率小、容易大量製造、太 低廉而大受歡迎。但也因為半導體材料本身能階的 而只倉b產生某些特疋的波長輸出，並且輸出功率 ， 無法滿足許多須要高功率同調光源的應用，這 祕昨 制了半導體雷射的應用領域。 ^ ^特性限With the rapid evolution of laser technology, various lasers have been widely used in different fields. Traditionally, most laser light emits coherent electromagnetic radiation of a fixed wavelength or frequency by using the transition of electrons or carriers between different energy levels. Taking solid-state lasers as an example, solid-state lasers have become the mainstream of all types due to the simple and lightweight system and the booming development of optoelectronic materials science in recent years. Semiconductor lasers are the most typical example. Radiation is popular because of its small size, low power consumption for operation, easy mass production, and low cost. However, because of the energy level of the semiconductor material, only the bin b produces some special wavelength output, and the output power cannot meet many applications that require high-power coherent light sources. This has created a field of semiconductor laser applications. ^ ^ Characteristic limit
然而，許多應用中都需要可調波長的雷射光 如，在偵測環境微量氣體方面，因為不同氣體會f Ρ 的吸收波長，可調波長的雷射加上光譜偵測系 ^However, laser light with adjustable wavelength is required in many applications. For example, in the detection of trace gases in the environment, because different gases will absorb the wavelength of f PF, laser with adjustable wavelength plus spectral detection system ^
用在多種微量氣體的債测及分析。又例如，在全^ g JDetect and analyze a variety of trace gases. For another example, in full ^ g J
1225948 _ 五、發明說明（2) 平面顯示器方面，每一像點（p i X e 1)係由發出紅、綠、藍 三色波長的雷射光源選擇性地聚焦產生。雖然部分雷射 光源，如染料雷射（dye laser)、自由電子雷射（free- electron laser)與一些非線性晶體雷射，均可在一定程 度下調整其發射出雷射的波長，但是其波長可調範圍仍 不夠大，且價格昂貴、能量轉換效率低、操作不便。 在最近幾年，隨著非線性光學的快速發展，可調波 長雷射亦有長足的進步。較常使用的二階極化非線性光 學效應係藉由一個或二個入射雷射光源（在某些情形下、 如倍頻，該二入射光源可藉由同一雷射源而得）依同一路 徑地通過一非線性光學晶體而產生混頻作用，藉以發出 $ 一預期中的特殊波長雷射。其中，二階非線性光學效應 (second-order nonlinear optical effect)包括二階 諧頻產生（Second Harmonic Generation; SHG)、差頻產 生（Difference Frequency Generation; DFG)、和頻產 生（Sum Frequency Generation; SFG)以及光參數產生、 光參數放大和光參數振盈（Optical Parametric Generation, Amplification, Oscillation; OPG, OPA, 0 P 0 )等。在二階非線性轉換的過程中，如果所發出的雷 射信號和其它二個雷射光信號在晶體中達到相位匹配 (phase-matching)時，所發出雷射的強度會因通過晶體 的長度而累積增強。如果此三道雷射光的相位不匹配，|| 所發出雷射的強度則無法持續增強。在非線性光學晶體 中，可使所欲發出的雷射信號強度累積增強的距離稱為1225948 _ V. Description of the invention (2) In the flat display, each image point (pi x e 1) is generated by selective focusing of a laser light source that emits three wavelengths of red, green and blue. Although some laser light sources, such as dye lasers, free-electron lasers, and some nonlinear crystal lasers, can all adjust the wavelength of their laser emission to a certain extent, but The wavelength tunable range is still not large enough, and it is expensive, has low energy conversion efficiency, and is inconvenient to operate. In recent years, with the rapid development of nonlinear optics, tunable-wavelength lasers have also made great progress. The more commonly used second-order polarized nonlinear optical effects are caused by one or two incident laser sources (in some cases, such as frequency doubling, the two incident sources can be obtained from the same laser source) following the same path Ground passes through a non-linear optical crystal to produce a mixing effect, thereby emitting a special wavelength laser as expected. The second-order nonlinear optical effect includes second-order harmonic generation (SHG), difference frequency generation (DFG), and sum frequency generation (SFG), and Optical parameter generation, optical parameter amplification, and optical parametric vibration (Optical Parametric Generation, Amplification, Oscillation; OPG, OPA, 0 P 0), etc. During the second-order non-linear transformation, if the emitted laser signal and the other two laser light signals reach phase-matching in the crystal, the intensity of the emitted laser will be accumulated as it passes through the length of the crystal Enhanced. If the phases of the three laser lights do not match, the intensity of the laser emitted by || cannot be continuously increased. In non-linear optical crystals, the distance that can increase the intensity of the laser signal to be emitted is called
第11頁 1225948_ 五、發明說明（3) 一個同調長度（coherence length)。因此，在相位不匹 配的情形下，發出雷射的強度至多僅能經由單一同調長 度而累積，通常在這種情形下該同調長度只有數微米 (mm )的大小。故要使三信號達到相位匹配的情形，須巧 妙設計晶體的非線性光學特性，以使所欲產生的雷射強 度在非線性晶體中持續增長。由於溫度也可以改變晶體 的折射率，從而改變相位匹配的條件，因此改變非線性 晶體溫度是調整射出雷射波長的方法之一。 准相位/匹配非線性雷射是最近為改良可調波長雷射 的效率而發展出來的。參見Fejer at el.發表的’’Quasi -Phase-Matched Second Harmonic Generation: Tuning A and Tolerances,M IEEE Journal of QuantumPage 11 1225948_ V. Description of the invention (3) A coherence length. Therefore, in the case of phase mismatch, the intensity of the emitted laser can only be accumulated at most through a single coherence length, and usually the coherence length is only a few micrometers (mm) in this case. Therefore, in order to achieve the phase matching of the three signals, it is necessary to design the nonlinear optical characteristics of the crystal cleverly so that the laser intensity to be generated continuously increases in the nonlinear crystal. Since the temperature can also change the refractive index of the crystal, thereby changing the conditions of phase matching, changing the nonlinear crystal temperature is one of the methods to adjust the laser wavelength. Quasi-phase / matched nonlinear lasers have recently been developed to improve the efficiency of tunable wavelength lasers. See’’Quasi -Phase-Matched Second Harmonic Generation: Tuning A and Tolerances, M IEEE Journal of Quantum by Fejer at el.
Electronics, vol· 28， 1992 pp· 2631-2654 ，以及美 國專利第5, 036, 220 號、第5,800, 767 號、第5, 714, 198 號、第5，838，702號等。准相位匹配（Quasi 一 phase matching; QPM)技術主要是在非線性光學晶體上製作週 期性晶格極化反轉來補償因色散效應而導致在晶體内作 頻率轉換交互作用的光波其相速度的差異，如此，將可 在此類晶體上遠成以非臨界相位匹配（noncritical phase-matching)方式於其光透明波長區間内作任何的波 長交互作用與轉換。以此准相位匹配的補償方式，將可 使交互作用的光波運用此晶體非線性係數張量中的最大 元素而達成較高的非線性轉換效率。 在前述技術的架構中，晶體的二階非線性光學係數Electronics, vol. 28, 1992 pp. 2631-2654, and U.S. Patent Nos. 5, 036, 220, 5,800, 767, 5, 714, 198, 5,838, 702, etc. Quasi-phase matching (QPM) technology is mainly to make periodic lattice polarization inversion on non-linear optical crystals to compensate for the phase velocity of light waves that interact with frequency conversion in the crystal due to dispersion effects. The difference, in this way, will be able to make any kind of wavelength interaction and conversion in a non-critical phase-matching manner within its optically transparent wavelength range on such crystals. With this quasi-phase-matched compensation method, the interacting light waves can use the largest element in the nonlinear coefficient tensor of the crystal to achieve high nonlinear conversion efficiency. In the framework of the aforementioned technology, the second-order nonlinear optical coefficient of the crystal
第12頁 1225948 五、發明說明（4) 以每一同調長度為單位作週期性的變號，用以達到相位 匹配的目的（此即稱為准相位匹配），並有效產生另一頻 率的雷射光。因此吾人可利用准相位匹配技術選擇非線 性晶體中最大的非線性光學係數來達到最大的雷射能量 轉換效率。週期性變號通常是利用週期性地改變鐵電物 質（ferroelectric material)的自發極化（sp〇ntane〇us polarization)方向而完成。除了幫浦雷射的波長與操作 溫度，交替極化區域的間隔週期決定發出雷射的波長。 當幫浦雷射波長及鐵電物質的光柵週期都被固定時，可 利用改變溫度來小幅調整發出雷射的波長。許多鐵電物 質（ferroelectric material)可以形成相當良好的准相 _ 位匹配非線性光學晶體’例如銳酸鐘（L i N b 0 3)、组酸鐘 (LiTa03)、銳酸鉀（KNb03)、鱗酸氧鈦鉀（KTi0P04;KTP)、 砷酸氧鈦铷（RbTi0As04; RTA)、磷酸氧鈦铷（RbTi0P04)等 等。 第一圖（A)所示為一種習用之准相位匹配非線性光學 晶體1 0 1 ，該晶體1 0 1僅具有單一光柵週期，所以在該晶 體中只有一種非線性光學效應可以達成相位匹配。例如Page 1212948948 V. Explanation of the invention (4) Periodically change the number with each homology length as a unit to achieve the purpose of phase matching (this is called quasi-phase matching) and effectively generate lightning at another frequency Shoot light. Therefore, we can use the quasi-phase matching technology to select the largest nonlinear optical coefficient in the nonlinear crystal to achieve the maximum laser energy conversion efficiency. Periodically changing the number is usually accomplished by periodically changing the direction of spontaneous polarization of the ferroelectric material. In addition to the wavelength and operating temperature of the pump laser, the interval period of the alternately polarized region determines the wavelength of the emitted laser. When the pump laser wavelength and the grating period of the ferroelectric material are fixed, the wavelength of the laser can be adjusted slightly by changing the temperature. Many ferroelectric materials (ferroelectric materials) can form fairly good quasi-phase-matching nonlinear optical crystals' such as a sharp acid bell (L i N b 0 3), a group acid bell (LiTa03), a potassium sharp acid (KNb03), Potassium oxotitanate (KTi0P04; KTP), oxotitanium arsenate (RbTi0As04; RTA), oxotitanium phosphate (RbTi0P04), and so on. The first figure (A) shows a conventional quasi-phase-matching nonlinear optical crystal 1 0 1, which has only a single grating period, so there is only one kind of nonlinear optical effect in the crystal to achieve phase matching. E.g
Myers 等人發表之"Quasi - phase - matching 1. 064 //m -pumped optical parametric oscillator in bulk periodically poled LiNb03,,f OPTICS LETTERS ν〇1·20，Νο·1， Jan. 1995, ρρ·52-54。第一圖（B)所示為 〇 另一種習用之准相位匹配非線性光學晶體1 〇 2，該晶體 1 0 2係由不同光栅週期的二部分單晶組成，所以具有使兩Myers et al. &Quot; Quasi-phase-matching 1. 064 // m -pumped optical parametric oscillator in bulk periodically poled LiNb03,, f OPTICS LETTERS ν〇1 · 20, No. 1, Jan. 1995, ρρ52 -54. The first figure (B) shows 〇 Another conventional quasi-phase-matching nonlinear optical crystal 1 02, which is composed of two part single crystals with different grating periods.
第13頁 1225948_ 五、發明說明（5) 種非線性光學效應達成相位匹配的能力。例如Rosenberg 發表之丨丨 2.5-W continuous-wave, 629-nm solid-state laser source", Optics Letters, Vo 1. 23 No. 1 ,Page 13 1225948_ V. Description of the invention (5) The ability to achieve phase matching with 5 kinds of nonlinear optical effects. For example, published by Rosenberg 丨 2.5-W continuous-wave, 629-nm solid-state laser source ", Optics Letters, Vo 1. 23 No. 1,
February 1， 1998， pp· 207-209 ，以及美國專利第 5, 768, 302 號 。 在於這類的准相位匹配（Quasi-Phase-Matching; Q Ρ Μ )非線性光學晶體中，晶體的非線性光學參數會於雷 射行進方向作週期性的變號。舉例而言，准相位匹配 (Quasi-Phase-Mat chi ng; QPM)技術使二階非線性轉換過 程符合下列之准相位匹配條件： η3(Τ)/ λ3 ~ η2(Τ)/ λ2 ~ ηχ(Ί)/ Aj = 1/ Λ ( 1痛 同時符合量子光學中之能量守悝條件 1/ 入 3-1/λ2 - 1/入1 = 〇 (2) 其中，Λ是准相位匹配非線性光學晶體之晶格反轉光柵週 期，又u，3是三混合波之真空波長，以及ηι,2 3(τ)為以波長 為λ u，3等三波分別在晶體内之折射率。由於折射 物質及溫度而定，因此晶體溫度了將決定式（丨）中的 率的值。對一已知的光栅週期、及任意一個混頻波=， 兩個聯立式（1， 2)可以解出另外未知的兩個混合波的波 J。然而，二-晶f組成的二光柵在進行非線性光學變 :准：位匹配光柵區產生之波長报難在相同溫度n :足：二准：”匹配光柵區之准相位 外 當溫度稍有變化時，亦可能造成其中一光柵的：位=February 1, 1998, pp. 207-209, and U.S. Patent No. 5,768,302. In this type of Quasi-Phase-Matching (QPM) nonlinear optical crystal, the nonlinear optical parameters of the crystal will be changed periodically in the direction of laser travel. For example, Quasi-Phase-Mat chi ng (QPM) technology enables the second-order nonlinear conversion process to meet the following quasi-phase matching conditions: η3 (Τ) / λ3 ~ η2 (Τ) / λ2 ~ ηχ (Ί ) / Aj = 1 / Λ (1 pain also meets the energy conservation conditions in quantum optics 1 / in 3-1 / λ2-1 / in 1 = 〇 (2) where Λ is the quasi-phase-matching nonlinear optical crystal The lattice inversion grating period, and u, 3 is the vacuum wavelength of the three mixed waves, and η, 2 3 (τ) is the refractive index of the three waves in the crystal with a wavelength of λ u, 3. Due to the refractive material and temperature However, the crystal temperature will determine the value of the rate in equation (丨). For a known grating period and any mixing wave =, two simultaneous equations (1,2) can solve another unknown Wave J of the two mixed waves. However, the two gratings composed of two-crystal f are undergoing nonlinear optical transformation: quasi: the wavelength generated by the bit-matching grating region is difficult to report at the same temperature When the temperature changes slightly outside the quasi-phase of the zone, one of the gratings may also cause:
第14頁 1225948 五、發明說明（6) 配。此困難不僅造成實際之雷射輸出結果與設計不符、 亦造成雷射波長的可調幅度有限，且無法於晶體固定溫 度下或一溫度範圍内提供可連續調變波長之雷射，因此 無法滿足實際需要。 職是之故，本發明鑑於習知技術的缺失，乃經悉心 試驗與研究，並一本鍥而不捨之精神，終創作出本案之 『單週期與扇形光柵串連之准相位匹配非線性光學單一 晶體及利用該晶體之波長可調雷射產生裝置』’揭露一 種實用、新穎且進步的雷射產生架構，允許於晶體固定 溫度或一溫度範圍内做連續非線性頻率轉換與大幅度的 波長調整。 發明内容 本案的主要目的係為揭露一種單週期與扇形光柵串 連之准相位匹配非線性光學單一晶體，該晶體可以進行 雷射頻率轉換。 本案的次一目的係為提供一種非線性光學晶體，該 晶體可以在固定溫度或一溫度範圍下進行雷射頻率轉 換。 為達上述目的，本案提供一種准相位匹配非線性光 學單一晶體，其至少包括：一准相位匹配單一週期光柵 區，其沿一第一方向具有一第一光栅週期；以及一准相 位匹配扇形光柵區，其沿一第二方向具有一可調變之沿 該第一方向之一第二光柵週期，且該第二光栅週期其週 期大小係隨著該第二方向的位移變化而連續變化。其Page 14 1225948 V. Description of the invention (6) Matching. This difficulty not only causes the actual laser output results to be inconsistent with the design, but also results in a limited adjustable laser wavelength, and cannot provide a laser that can continuously adjust the wavelength at a fixed crystal temperature or within a temperature range. nessecery. Therefore, in view of the lack of known technology, the present invention has been carefully tested and researched, and has persevered in the spirit, and finally created the "single-period and fan-shaped grating series quasi-phase matching nonlinear optical single crystal in this case." And the use of the crystal's wavelength-tunable laser generation device "'discloses a practical, novel and progressive laser generation architecture that allows continuous non-linear frequency conversion and large-scale wavelength adjustment at a fixed temperature or a temperature range of the crystal. SUMMARY OF THE INVENTION The main purpose of this case is to disclose a quasi-phase-matching nonlinear optical single crystal with a single period and a fan-shaped grating series, which can perform laser frequency conversion. A secondary object of the present case is to provide a nonlinear optical crystal which can perform laser frequency conversion at a fixed temperature or a temperature range. To achieve the above object, the present invention provides a quasi-phase-matched nonlinear optical single crystal, which at least includes: a quasi-phase-matched single-period grating region having a first grating period in a first direction; and a quasi-phase-matched sector grating The region has a second grating period that is adjustable along a second direction along the first direction, and the period size of the second grating period is continuously changed as the displacement of the second direction changes. its
第15頁 1225948_ 五、發明說明（7) 中，該第二方向係垂直該第一方向。 本案的又一目的係提供一種使用上述准相位匹配單 一晶體之波長可調雷射產生裝置。該雷射產生裝置可以 利用該晶體於一固定溫度或一溫度範圍下連續選取該准 相位匹配扇形光柵區之一第二光柵週期進行雷射頻率轉 換’以提供波長連續可調之雷射。 為達上述目的，本案提供一種波長可調雷射產生裝 置，其至少包括：一准相位匹配非線性光學單一晶體，其 係具有一准相位匹配單一光栅區與一准相位匹配扇形光 栅區’其中該准相位匹配單一光柵區沿一第一方向具有 一第一光柵週期，而該准相位匹配扇形光栅區沿一第二 # 方向具有一可調變之沿該第一方向之一第二光栅週期， 且該第二光柵週期其週期大小係隨著該第二方向的位移 變化而連續變化，其中該第二方向係垂直於該第一方 向；以及至少一雷射輪入光源，用以提供具有至少一波 長^第二雷射信號沿該第一方向射入該准相位匹配非線 性光學單一晶體。藉此，當該第一雷射信號射入該准相 位匹^非線性光學單_晶體後，晶體内部因應各個光柵 特性會產生至少二個非線性光學頻率或波長轉換效應， 以射出具有至少一個不同於輸入波長之第二雷射信號。 也她T據本案之構想’本案晶體中單週期光柵區和扇形 週直I的，列順序並非固定，幫浦雷射光源可先射入單 〇 再=光，區再射入扇形光栅區，亦可先射入扇形光栅區 、入早週期光栅區。當幫浦雷射光源射入第一光栅區Page 15 1225948_ 5. In the description of the invention (7), the second direction is perpendicular to the first direction. Another object of the present invention is to provide a wavelength-tunable laser generating device using the above-mentioned quasi-phase matching single crystal. The laser generating device can use the crystal to continuously select a second grating period of the quasi-phase matching sector grating region at a fixed temperature or a temperature range to perform laser frequency conversion 'to provide a laser whose wavelength is continuously adjustable. In order to achieve the above object, the present invention provides a wavelength-tunable laser generating device, which at least includes: a quasi-phase-matching nonlinear optical single crystal, which has a quasi-phase-matching single grating region and a quasi-phase-matching fan-shaped grating region. The quasi-phase matching single grating region has a first grating period in a first direction, and the quasi-phase matching sector grating region has a second grating period in a second # direction which is adjustable along a second # direction. And the period size of the second grating period is continuously changed as the displacement of the second direction changes, wherein the second direction is perpendicular to the first direction; and at least one laser wheel enters the light source to provide At least one wavelength ^ the second laser signal enters the quasi-phase-matching nonlinear optical single crystal along the first direction. Thereby, after the first laser signal is incident on the quasi-phase-matched nonlinear optical single crystal, at least two nonlinear optical frequency or wavelength conversion effects will be generated in the crystal according to the characteristics of each grating to emit at least one A second laser signal different from the input wavelength. According to the idea of this case, the order of the single-period grating region and the fan-shaped perimeter I in the crystal of this case is not fixed. The pump laser light source can first enter the single 0 and then = light, and the region then enters the fan-shaped grating region. You can also shoot into the fan-shaped grating area and the early-cycle grating area first. When the pump laser light source enters the first grating region
Si? 第16頁 1225948 五、發明說明（8) 後，幫浦雷射的頻率會先作第一次轉換，當繼續射入第 二光柵區後，幫浦雷射的頻率又作第二次轉換。 根據本案之構想，該波長可調雷射產生裝置更包括 一溫控爐（temperature-controlling oven)，用以改變 晶體的准相位特性以增大波長調變範圍。 根據本案之構想，該波長可調雷射產生裝置更可包 括一共振腔，該共振腔可為設置於非線性光學晶體兩側 之二反射鏡，或為直接鍍於非線性光學晶體兩端面之二 反射薄膜。 根據本案之構想，該雷射產生裝置更可包括一環狀 共振腔結構，該環狀共振腔結構包括至少兩個反射鏡， 4 其係位於該非線性光學晶體沿該第一方向之兩側，以及 至少兩個反射鏡，其係位於該非線性光學晶體之外側。 根據本案之構想，該雷射產生裝置更包括一聚焦透 鏡或光學透鏡系統，其係用以將該第一雷射信號聚焦並 導引其射入該非線性光學晶體。 本案得藉由下列圖示即詳細說明，俾使一更深入之 瞭解： 圖示簡單說明 第一圖（A ) Μ系為習知技術之單週期准相位匹配非線 性光學曰曰曰體。 第一圖（Β ):係為另一習知技術之縱向串接雙週期准 相位匹配非線性光學晶體。Si? Page 16 1225948 V. Description of the invention (8), the frequency of the pump laser will be converted for the first time, and when it continues to enter the second grating region, the frequency of the pump laser will be changed for the second time. Conversion. According to the idea of the present case, the wavelength-tunable laser generating device further includes a temperature-controlling oven to change the quasi-phase characteristics of the crystal to increase the wavelength modulation range. According to the concept of the present case, the wavelength-tunable laser generating device may further include a resonant cavity, which may be two reflecting mirrors disposed on both sides of the non-linear optical crystal, or may be directly plated on both ends of the non-linear optical crystal. Two reflective films. According to the idea of the present case, the laser generating device may further include a ring-shaped resonant cavity structure including at least two reflectors, 4 located on both sides of the nonlinear optical crystal along the first direction, And at least two mirrors, which are located outside the non-linear optical crystal. According to the concept of the present case, the laser generating device further includes a focusing lens or an optical lens system, which is used to focus the first laser signal and guide it to the non-linear optical crystal. This case can be explained in detail by the following diagrams, in order to make a deeper understanding: The diagram is briefly explained. The first diagram (A) M is a single-cycle quasi-phase-matched nonlinear optical system of conventional technology. The first figure (B) is a longitudinally-connected double-period quasi-phase-matching nonlinear optical crystal of another conventional technique.
第17頁 1225948 五、發明說明（9) 第二圖：係為本案准相位匹配非線性光學單一晶體之 第一較佳實施例示意圖。 第三圖··係為本案准相位匹配非線性光學單一晶體之 另一較佳實施例示意圖。 第四圖··係為本案雷射差生裝置之第一較佳實施例示 意圖，其中該雷射產生裝置未使用共振反射鏡組。 第五圖：係為本案雷射產生裝置之第二較佳實施例示 意圖，其中該晶體兩側具有二共振反射鏡。 第六圖：係為本案雷射產生裝置之第三較佳實施例示 意圖，其中該晶體兩端面鍍有二光學薄膜。 第七圖：係為本案雷射產生裝置之第四較佳實施例示· 意圖。 圖示符號說明 1 0 1 :單週期准相位匹配非線性光學晶體 1 0 2 :縱向串接雙週期非線性光學晶體 2 0 1 :串接單週及扇形光柵准相位匹配非線性光學單一 晶體 2 0 1 1 :單週光栅區 2 0 1 2 :扇形光栅區Page 17 1225948 V. Description of the invention (9) The second figure: a schematic diagram of the first preferred embodiment of the quasi-phase-matched nonlinear optical single crystal of this case. The third figure is a schematic diagram of another preferred embodiment of the quasi-phase-matched nonlinear optical single crystal of the present invention. The fourth figure shows the first preferred embodiment of the laser differential device of the present invention, wherein the laser generating device does not use a resonance mirror group. Fig. 5 is a schematic view of a second preferred embodiment of the laser generating device of the present invention, wherein two sides of the crystal have two resonance mirrors. Fig. 6 is a schematic view of a third preferred embodiment of the laser generating device of the present invention, in which two optical films are plated on both ends of the crystal. The seventh figure: the fourth preferred embodiment of the laser generating device of this case. Explanation of symbols 1 0 1: Single-period quasi-phase-matching nonlinear optical crystal 1 0 2: Longitudinal series-connected bi-period-linear nonlinear optical crystal 2 0 1: Single-periodic and sector grating quasi-phase-matching nonlinear optical single crystal 2 0 1 1: Single-circle grating area 2 0 1 2: Fan-shaped grating area
3 0 1 :幫浦雷射光源 U 3 0 2 :聚焦透鏡或光學透鏡系統 胃1 303, 304, 305, 306:串接單週及扇形光栅准相位匹配非 線性光學單一晶體3 0 1: Pump laser light source U 3 0 2: Focusing lens or optical lens system Stomach 1 303, 304, 305, 306: Single-periodic and sector grating quasi-phase-matched non-linear optical single crystal in series
第18頁 1225948 五、發明說明（10) 3031，3041，3051，3061:單週光柵區 3 0 3 2，3 0 4 2，3 0 5 2，3 0 6 2 :扇形光栅區 401，403, 405, 407:溫控爐 501，502:共振腔反射鏡 5 0 3，5 0 4 :光學薄膜 505, 506:共振腔反射鏡 實施方法 壹·准相位匹配非線性光學單一晶體 第二圖所示為本案之准相位匹配非線性光學單一晶 體。該串接單週及扇形光柵准相位匹配非線性光學單一 4 晶體2 01較佳為單晶晶格極化反轉之鐵電物，例如鈮酸鋰 (LiNb03)、鈕酸鋰（LiTa03)、鈮酸鉀（KNb03)、磷酸氧鈦鉀 (KTi0P04;KTP)、砷酸氧鈦铷（RbTi0As04;RTA)、磷酸氧鈦 铷（RbTi0P04)或其他類似物等。於此實施例中，串接單 週及扇形光柵准相位匹配光學單一晶體2 0 1之光柵設計包 括兩部分-單週光栅區（single_peri〇d grating)2011與 扇形光栅區（fan-out grating)2012。該單週光柵區2011 沿第一方向具有一非線性光學特性，該第一方向即為光 栅週期方向與雷射進行方向。該扇形光栅區2 〇 1 2沿第二 方向具有調變沿該第一方向之非線性光學特性，其中該 第二方向係與該第一方向互相垂直。 着| 當應用上述之非線性光學單一晶體2 〇 1時，可藉由調 變晶體201橫向（亦即該第二或y方向）之位置，以選擇扇Page 18 1225948 V. Description of the invention (10) 3031, 3041, 3051, 3061: single-cycle grating area 3 0 3 2, 3 0 4 2, 3 0 5 2, 3 0 6 2: sector grating area 401, 403, 405, 407: Temperature controlled furnace 501, 502: Resonant cavity mirror 5 0 3, 5 0 4: Optical film 505, 506: Resonant cavity mirror implementation method I. Quasi-phase matching nonlinear optical single crystal This case is a quasi-phase-matched nonlinear optical single crystal. The cascaded single-circle and sector-shaped grating quasi-phase-matching non-linear optical single 4 crystal 2 01 is preferably a single crystal lattice inversion ferroelectric material, such as lithium niobate (LiNb03), lithium button acid (LiTa03), Potassium niobate (KNb03), potassium titanyl phosphate (KTi0P04; KTP), titanyl arsenate (RbTi0As04; RTA), titanyl phosphate (RbTi0P04), or the like. In this embodiment, the grating design of the single-period and sector-shaped grating quasi-phase-matched optical single crystal 201 connected in series includes two parts-a single-period grating region (single_period grating) 2011 and a fan-out grating region. 2012. The single-circle grating region 2011 has a non-linear optical characteristic along a first direction, and the first direction is a grating periodic direction and a laser traveling direction. The fan-shaped grating region 20 has a non-linear optical characteristic that is modulated along the first direction along a second direction, wherein the second direction is perpendicular to the first direction.着 | When applying the above-mentioned non-linear optical single crystal 201, the fan can be selected by adjusting the position of the crystal 201 in the lateral direction (that is, the second or y direction).
第19頁 1225948 五、發明說明（11) 形光柵區2 0 1 2之最適光柵週期，使晶體2 〇 1之非線性頻率 轉換最適化。此外’串接單週及扇形光栅准相位匹配光 學單一晶體201中之單週光柵區2011和扇形光柵區2012排 列順序並非固定，可視應用而將單週光柵區2 〇 1 1排列於 扇形光栅區2 0 1 2之前（相對於幫浦雷射源），亦可將扇形 光栅區2 0 1 2排列於單週光栅區2 〇 1 1之前（如第三圖所 示）。藉由上述之晶體光柵結構，當幫浦雷射光源（未圖 示）所發出之雷射射入第一光柵區（如第二圖之單週光栅 區2 0 1 1或第三圖之扇形光柵區2 〇 1 2 )後，幫浦雷射的頻率 會先作第一次轉換，當繼續射入第二光柵區（如第二圖之 扇形光柵區2012或第三圖之單週光柵區2011)後，幫浦雷4 射的頻率又作第二次轉換，因此可藉由此晶體而達到准 相位匹配雷射頻率轉換之目的。然而，必須注意的是， 本案晶體中的光柵設計可以具有其他的修飾與變化，並 不限於以上揭露的較佳實施例而已。 貳·利用單週期與扇形光柵串連之准相位匹配光學單一晶 體之波長可調雷射產生裝置及實施例 A·波長可調之二階二次諧振（SHG)加光參數產生（〇pG)雷 射：Page 19 1225948 V. Description of the invention The optimum grating period of the (11) shaped grating region 2 0 1 2 is to optimize the nonlinear frequency conversion of the crystal 2 0 1. In addition, the arrangement order of the single-circle grating region 2011 and the fan-shaped grating region 2012 in the single-cycle and sector-shaped grating quasi-phase matching optical single crystal 201 is not fixed. Depending on the application, the single-circle grating region 201 is arranged in the fan-shaped grating region. Before 2 0 1 2 (relative to the pump laser source), the sector grating area 2 0 1 2 can also be arranged before the single-circle grating area 2 0 1 1 (as shown in the third figure). With the above-mentioned crystal grating structure, when the laser emitted by the pump laser light source (not shown) enters the first grating region (such as the single-circle grating region of the second figure 2 0 1 1 or the fan shape of the third figure) After the grating area 2 0 1 2), the frequency of the pump laser will be converted for the first time. When it continues to enter the second grating area (such as the fan-shaped grating area 2012 of the second picture or the single-circle grating area of the third picture) After 2011), the frequency of the pump 4 laser is converted for the second time, so the quasi-phase matching laser frequency conversion can be achieved by this crystal. However, it must be noted that the grating design in the crystal of the present case may have other modifications and changes, and is not limited to the preferred embodiments disclosed above.贰 · A wavelength-tunable laser generating device using a quasi-phase-matching optical single crystal connected in series with a sector grating and a single period and the embodiment A · The wavelength-tunable second-order second-resonance (SHG) plus light parameter generation (〇pG) thunder Shoot:
第四圖所示為本案雷射產生裝置的第一較佳實施 II 例。該雷射產生裝置主要包括一幫浦雷射光源3〇1 、一聚 焦透鏡或光學透鏡系統3 〇 2以及一串接單週及扇形光柵准The fourth figure shows the first preferred embodiment II of the laser generating device of this case. The laser generating device mainly includes a pump laser light source 301, a focusing lens or optical lens system 302, and a series of single-circle and sector-shaped grating standards.
第20頁 1225948 五、發明說明（12) 相位匹配光學單一晶體3 〇 3。幫浦雷射光源3 〇 1係用以發 出一具有第一波長的輸入雷射信號以進入串接單週及扇 形光柵准相位匹配非線性光學單一晶體3 0 3。聚焦透鏡或 光學透鏡系統3 0 2係用以將輸入雷射信號聚焦並導引其射 入正確位置。將幫浦雷射光源3 〇 1所產生之雷射信號射入 該串接單週及扇形光柵准相位匹配光學單一晶體3 〇 3後， 晶體3 0 3將進行前述之雷射頻率轉換，且將射出一預設波 長的雷射光束。於此實施例中，該串接單週及扇形光柵 准相位匹配光學單一晶體3 〇 3可設置於一溫控爐4 〇 1中， 藉以改變及控制該晶體3 〇 3溫度。該溫控爐4 0 1係用以改 變晶體3 0 3的准相位特性，以利用溫度變化來輸出特定波_ 長範圍之雷射光束。 於上述實施例中，串接單週及扇形光柵准相位匹配 光學非線性單一晶體3 0 3以經過週期性晶格極化反轉之銳 酸鐘（periodically poled lithium nibobate; PPLN)為 較佳。其中，單一光柵區3〇31的長度可約為，其光 栅週期（Λ )為6 · 6 7mm，可在1 0 0 t：利用二階二次諧振 (second - order SHG)將幫浦光源301所發出之1064 -nm幫 浦雷射倍頻，以轉換為一 5 3 2 nm之雷射輸出至扇形光柵區 3032。另外，扇形光栅區3032的長度可約為4cm，其光栅 週期（Λ )於5mm之橫向（亦即該第二或y方向）寬度可連續 調變於11-12 mm之間。在1〇〇 °c時當該5 3 2 nm的雷射射入扇餐I 形光柵區3 0 3 2時，扇形光柵區3 0 3 2將以可調變之光參數 產生過程（0PG)輸出波長範圍618nm至590nm之雷射。換言Page 20 1225948 V. Description of the invention (12) Phase matching optical single crystal 3 03. The pump laser light source 301 is used to emit an input laser signal having a first wavelength to enter a series of single-cycle and fan-shaped grating quasi-phase-matched nonlinear optical single crystal 303. The focusing lens or optical lens system 3 2 is used to focus the input laser signal and guide it to the correct position. After the laser signal generated by the pump laser light source 3 〇1 is injected into the cascaded single-circle and sector-shaped grating quasi-phase matching optical single crystal 3 〇3, the crystal 303 will perform the aforementioned laser frequency conversion, and A laser beam of a predetermined wavelength will be emitted. In this embodiment, the cascaded single-circle and sector grating quasi-phase matching optical single crystal 3 03 can be set in a temperature-controlled furnace 4 01 to change and control the temperature of the crystal 3 03. The temperature-controlled furnace 4 01 is used to change the quasi-phase characteristics of the crystal 3 0 3 so as to use the temperature change to output a laser beam with a specific wave length range. In the above-mentioned embodiment, it is preferable to connect a single-cycle and sector-shaped grating quasi-phase-matched optically nonlinear single crystal 3 0 3 with a periodically poled lithium nibobate (PPLN) undergoing periodic lattice polarization inversion. Among them, the length of a single grating region 3031 can be approximately, and its grating period (Λ) is 6.67 mm, which can be at 100 t: using the second-order SHG, the pump light source 301 is The 1064-nm pump laser frequency multiplied is converted to a 5 3 2 nm laser output to the sector grating region 3032. In addition, the length of the fan-shaped grating region 3032 may be about 4 cm, and the width of the grating period (Λ) of 5 mm in the lateral direction (that is, the second or y direction) may be continuously adjusted between 11-12 mm. At 100 ° C, when the 5 3 2 nm laser beam enters the fan-shaped I-shaped grating region 3 0 3 2, the fan-shaped grating region 3 0 3 2 will be generated with adjustable light parameters (0PG). Lasers with output wavelengths ranging from 618nm to 590nm. In other words
第21頁 1225948 五、發明說明（13) 之，利用單週光柵區3 〇 3 1於1 0 0 °C相位匹配所產生之 532 nm雷射，當該532 nm雷射於扇形光栅區3032橫向（亦即 沿該第二或y方向）地掃描1 1 - 1 2 m m之光栅週期時，扇形光 栅區3 0 3 2可藉由光參數產生（〇PG)過程以於相同之溫度下 產生波長範圍618nm至590nm、波長連續可調之雷射光 束。藉此該雷射產生裝置可於晶體單一固定溫度下產生 連續可調波長之雷射。 另外，幫浦雷射光源3 0 1較佳者係為一摻歛q -開關雷 射（Nd3+ Q-switched laser)，其發出波長為 i〇64nm。由 於幫浦雷射的最高峰值功率可以超過十數千瓦 (kilowatt)以上，所以幫浦雷射在經過單週光柵區3〇31 φ 可以經由二次簡諧振盪的非線性轉換機制將雷射能量幾 乎全部轉換為波長為532nm的雷射。此532nm的雷射會繼 續通過扇形光柵區3 0 3 2，並在扇形光柵區3 〇 3 2中經由光 學參數過程產生雷射光。 B·波長可調之光參數振盪（0P0)加二階二次諧振（shg)雷 射 在非線性雷射波長轉換過程中，為共振一個或多個 雷射#號以減少幫浦閾值（pumping threshold)並增強整 體雷射轉換效率，可如第五圖至第七圖實施例所示藉由 增加一共振腔而達成。 〇 第五圖所示為本案雷射產生裝置的第二較佳實施 例。於此實施例中，雷射產生裝置主要包括一幫浦雷射Page 21 1225948 V. Description of the invention (13) In the 532 nm laser generated by phase matching of the single-cycle grating region 3 0 03 1 at 100 ° C, when the 532 nm laser is transverse to the sector grating region 3032 When scanning a grating period of 1 1-12 mm (that is, along the second or y direction), the fan-shaped grating region 3 0 3 2 can generate a wavelength at the same temperature through the optical parameter generation (〇PG) process. Laser beam with continuously adjustable wavelength ranging from 618nm to 590nm. In this way, the laser generating device can generate a continuously adjustable wavelength laser at a single fixed temperature of the crystal. In addition, the pump laser light source 3 01 is preferably a doped q-switched laser (Nd3 + Q-switched laser), and its emission wavelength is 106 nm. Because the highest peak power of pump lasers can exceed tens of kilowatts (kilowatt), pump lasers can pass through a single-cycle grating region of 3031 φ, which can convert the laser energy through a second-order harmonic resonance nonlinear conversion mechanism. Almost all are converted into lasers with a wavelength of 532 nm. This 532nm laser will continue to pass through the fan-shaped grating region 3302 and generate laser light through the optical parameter process in the fan-shaped grating region 3302. B. Wavelength adjustable optical parameter oscillation (0P0) plus second-order second-resonance (shg) laser During the nonlinear laser wavelength conversion process, one or more lasers # are resonated to reduce the pumping threshold. ) And enhance the overall laser conversion efficiency, which can be achieved by adding a resonant cavity as shown in the fifth to seventh embodiments. 〇 Figure 5 shows the second preferred embodiment of the laser generating device of the present invention. In this embodiment, the laser generating device mainly includes a group of lasers.
第22頁 1225948 五、發明說明（14) 无綠dui、一聚焦透鏡或光學透鏡系統3〇2、一串接單週 及扇开> 光柵准相位匹配光學單一晶體3 〇 4，以及一共振腔 (由反射鏡5 01與502所組成）。該雷射產生裝置可於晶體 3 0 4之溫度調變於3 〇 t至丨5 〇 〇c間時，產生波長範圍介於 775ηπι至800nm間、波長連續可調之雷射光束。Page 22 1225948 V. Description of the invention (14) No green dui, a focusing lens or optical lens system 302, a series of single cycles and fan openings> grating quasi-phase matching optical single crystal 3 〇4, and a resonance Cavity (composed of mirrors 501 and 502). The laser generating device can generate a laser beam with a continuously adjustable wavelength in a wavelength range of 775 ηπ to 800 nm when the temperature of the crystal 300 is adjusted between 300 and 500 c.
於上述實施例中，幫浦雷射光源3 0 1係用以發出〆具 有第一波長的輸入雷射信號以進入晶體3〇4。聚焦透鏡戒 光學透鏡系統3 0 2係用以將輪入雷射信號聚焦並導引其射 入正確位置。將幫浦雷射光源3〇1所產生之雷射訊號射入 該准相位匹配光學單一晶體3 〇 4後，晶體3 〇 4將進行前述 之雷射頻率轉換，且將射出一預設波長範圍的雷射。晶 體3 04的兩側具有由二反射鏡5〇1， 5 0 2所組成之一共振 腔，用以循環一個或多個雷射信號以減少幫浦閥值 (pumping threshold)增強整體雷射轉換效率。另外，該 串接單週及扇形光柵准相位匹配光學單一晶體3 〇 4可設置 於一溫控爐4 0 3中’藉以改變及控制該晶體3 〇 4溫度。該 /孤控爐4 0 3係用以改變晶體3 〇 4的准相位特性，以利用溫 度變化來調整輸出雷射的波長。In the above embodiment, the pump laser light source 301 is used to emit an input laser signal having a first wavelength to enter the crystal 304. Focusing lens or optical lens system 3 0 2 is used to focus the wheel laser signal and guide it to the correct position. After the laser signal generated by the pump laser light source 30 is injected into the quasi-phase matching optical single crystal 3 04, the crystal 3 04 will perform the aforementioned laser frequency conversion and emit a preset wavelength range. Laser. Crystal 3 04 has a resonant cavity composed of two mirrors 501, 50 2 on both sides, which is used to circulate one or more laser signals to reduce the pumping threshold and enhance the overall laser conversion. effectiveness. In addition, the tandem single-circle and sector-shaped grating quasi-phase matching optical single crystal 304 can be set in a temperature-controlled furnace 403 'to change and control the temperature of the crystal 304. The / solitary furnace 403 is used to change the quasi-phase characteristics of the crystal 304 to adjust the output laser wavelength by using temperature changes.
於上述實施例中，幫浦雷射光源3 〇 1較佳者係為一掺 歛Q-開關雷射（Nd3+ Q - switched laser)，其發出波長為 1 0 6 4 n m。另外，串接單週及扇形光柵准相位匹配非線性' 光學單一晶體3 0 4以經過週期性晶格極化反轉之鈮酸鐘 (periodically poled lithium nibobate; PPLN)為參 佳，且該晶體3 0 4係由兩·部分光柵區所組成。該兩部分乂光In the above embodiment, the pump laser light source 3 01 is preferably a doped Q-switched laser (Nd3 + Q-switched laser) with an emission wavelength of 10 6 4 n m. In addition, tandem single-cycle and sector-shaped grating quasi-phase-matching nonlinear 'optical single crystal 3 0 4 is based on periodic poled lithium nibobate (PPLN) after periodic lattice polarization inversion, and the crystal The 3 0 4 system consists of two partial grating regions. The two parts are light
12259481225948
為光柵週期30mni之單週光栅區3〇41，以及光柵 3m 3 5 Γ之、橫向（亦即該第二或7方向）寬度變化於19_ Φ 2 ^ ^形光柵區3 〇 4 2。單週光栅區3 0 4 1於此實施例 1¾ VfU !?目il二t 5盪（〇P〇 )過程之增益媒介，而扇形光栅 ''為第二階准相位匹配二次諧頻產生器（th i rd- order QPM SHG) 〇 # & ^晶體3 〇 4溫度為3 0 °C時，單週光柵區3 〇 4 1 (光柵週 』為3〇111111之週期性晶格極化反轉鈮酸鋰）共振腔中會以 lj 5 Orim波長之光波振盪，稱為光學參數振蘯。同樣在晶 ，溫度為3 0 °C a寺，可橫向（亦即沿該第二或y方向）地調變 晶體3 04使得波長1 5 5 0 nm之光波掃描到扇形光柵區3〇42之一 19mm光柵週期。光柵週期為19mm之扇形光柵區3〇42將使 波長1 5 5 0㈣之光波於30 t下產生其倍頻光波，以產生波 長為7 7 5nm之雷射。為產生更多波長範圍且連續可調之雷 射，可將溫度調變至1 5 〇 °c ,於此情形下，單週光柵區 3 0 4 1中之准相位匹配條件將使光學參數振盪（〇 p 〇 )過程以 波長1 6 0 0 n m之光波振盪。藉由橫向（亦即沿該第二或y方 向）地调變串接單週及扇形光栅准相位匹配非線性光學單 一晶體3 0 4，可使得波長1 6 〇 〇 nm之光波掃描到扇形光柵區 3 0 4 2之19.8mm光柵週期。光栅週期為19.8mm之扇形光柵 區3042將使波長1600nm之光波於15〇°c下產生其倍頻光 波，以產生波長為800nm之雷射。藉此該雷射產生裝置便Φ 可於晶體3 0 4之溫度調變於30 t：至丨5〇。〇間時，產生波長 範圍介於7 7 5 nm至8 0 0 nm間之波長連續可調雷射。It is a single-circle grating region 3041 with a grating period of 30mni, and the width of the grating 3m 3 5 Γ in the lateral direction (that is, the second or 7 direction) is changed to 19_ Φ 2 ^ ^ shaped grating region 3 〇 4 2. The single-cycle grating region 3 0 4 1 is a gain medium in this embodiment 1 ¾ VfU 2 t 5 oscillating (〇P〇) process, and the fan-shaped grating is a second-order quasi-phase matching second harmonic generator (Th i rd-order QPM SHG) 〇 # & ^ Crystal 3 〇4 When the temperature is 30 ° C, the single-cycle grating region 3 〇41 (the grating cycle) is a periodic lattice polarization inversion of 3〇111111 Lithium niobate) resonators will oscillate with light waves with wavelengths of lj 5 Orim, which is called optical parametric vibration. Also in the crystal, the temperature is 30 ° C, and the crystal 3 can be modulated laterally (that is, along the second or y direction) so that the light wave with a wavelength of 1550 nm can be scanned to the fan grating region 3042. A 19mm grating period. A fan-shaped grating region 3042 with a grating period of 19 mm will cause a light wave with a wavelength of 1550 ㈣ to generate its frequency-doubling light wave at 30 t to generate a laser with a wavelength of 775 nm. In order to generate more wavelength range and continuously adjustable lasers, the temperature can be adjusted to 150 ° C. In this case, the quasi-phase matching conditions in the single-cycle grating region 3 0 4 1 will cause the optical parameters to oscillate (〇p 〇) The process oscillates with a light wave with a wavelength of 1660 nm. By adjusting the serially connected single-circle and sector grating quasi-phase-matched nonlinear optical single crystal 3 04 laterally (that is, along the second or y direction), a light wave with a wavelength of 1600 nm can be scanned to the sector grating Region 3 0 4 2 with 19.8mm grating period. A fan-shaped grating region 3042 with a grating period of 19.8 mm will cause a light wave with a wavelength of 1600 nm to generate its frequency-doubling light wave at 15 ° C to generate a laser with a wavelength of 800 nm. With this, the laser generating device can adjust the temperature of the crystal 304 to 30 t: to 50. Between 0 and 0, a continuously tunable laser with a wavelength ranging from 775 nm to 800 nm is generated.
第24頁 1225948 五、發明說明（16) 第六圖所不為本案雷射產生系統的第三較佳實施 例。為了減少雷射產生裝置的大小，第五圖中的反射鏡 5 〇 1， 5 0 2可被鍍於串接單週及扇形光栅准相位匹配非線 性光學單一晶體3 0 5兩端面的二光學薄膜5 0 3， 5 0 4取代。 當然，該光學薄膜503, 504的光譜反射率與曲率半徑玎以 隨系統需求而改變。另外，於此實施例中，雷射產生裝 置之各組件如幫浦雷射光源3 0 1、一聚焦透鏡或光學透鏡 系統3 0 2、——串接單週及扇形光柵准相位匹配光學單一晶 體3 0 5 (具單週光柵區3 0 5 1與扇形光栅區3 0 5 2 )與溫控爐 4 〇 5等之設計、原理及應用與第五圖所示之組件相似，因 此不再贅述。但應注意的是，若光學薄膜5 0 3, 5 0 4曲率半❿ 徑為無限大、形成兩面平面鏡，則本實施例通常較適用 於脈衝幫浦光源（pulsed pump source)。 第七圖所示為本案雷射產生裝置的第四較佳實施 例。於此實施例中，為了增加雷射產生裝置操作在單一 頻率之優點，可將第五圖中的反射鏡5 0 1， 5 0 2傾斜一特 定角度，並增加二共振腔反射鏡505, 506以形成一 Bow -T i e環型共振腔結構而達成。於此實施例中，兩反射鏡 5 0 1，5 0 2係位於串接單週及扇形光柵准相位匹配光學單一 晶體3 0 6沿該第一方向之兩側，另兩個共振腔反射鏡 5 〇 5，5 0 6則位於晶體3 0 6之外側。當然，於此實施例中， 雷射產生裝置之各組件如幫浦雷射光源301、一聚焦透鏡〇 或光學透鏡系統3 0 2、一串接單週及扇形光柵准相位匹配 光學單一晶體3 0 6 (具車一光栅區3 0 6 1與扇形光栅區3 〇 6 2 )Page 24 1225948 V. Description of the invention (16) The third preferred embodiment of the laser generating system in this case is not shown in the sixth figure. In order to reduce the size of the laser generating device, the mirrors 501, 502 in the fifth figure can be plated on the two optics on both ends of the single-crystal cascaded and sector-shaped grating quasi-phase-matched nonlinear optical single crystal 305. The film is replaced by 5 0 3, 5 0 4. Of course, the spectral reflectance and radius of curvature of the optical films 503, 504 will vary depending on the system requirements. In addition, in this embodiment, each component of the laser generating device, such as a pump laser light source 3 0 1, a focusing lens or optical lens system 3 0 2, —— serially connected single cycle and sector grating quasi-phase matching optical single The design, principle and application of crystal 3 0 5 (with single-circle grating region 3 0 5 1 and fan-shaped grating region 3 0 5 2) and temperature-controlled furnace 4 0 5 are similar to the components shown in the fifth figure, so they are no longer To repeat. However, it should be noted that if the curvature radius of the optical film 503, 504 is infinite, and two plane mirrors are formed, this embodiment is generally more suitable for a pulsed pump source. The seventh figure shows a fourth preferred embodiment of the laser generating device of the present invention. In this embodiment, in order to increase the advantage of the laser generating device operating at a single frequency, the mirrors 5 0 1, 5 0 2 in the fifth figure may be tilted by a specific angle, and two resonant cavity mirrors 505, 506 may be added. This is achieved by forming a Bow-Tie ring resonator structure. In this embodiment, two mirrors 501, 502 are located on both sides of the tandem and sector grating quasi-phase matching optical single crystal 3 0 6 along the first direction, and two other cavity mirrors 5 05, 5 6 is located outside the crystal 3 06. Of course, in this embodiment, the components of the laser generating device such as pump laser light source 301, a focusing lens 0 or an optical lens system 3 0 2, a series of single-period and fan-shaped grating quasi-phase matching optical single crystal 3 0 6 (with a car grating area 3 0 6 1 and a sector grating area 3 〇 6 2)
第25頁 1225948 五、發明說明（17) 與溫控爐4 0 7等之設計、原理及應用亦與第五圖所示之組 件相似’因此不再資述。 縱上所述，本案之准相位匹配非線性光學單一晶體 (monolithic crystal)之光柵設計包括單週期光柵區與 扇形光柵區，其中扇形光柵區於其橫向（亦即沿該第二或 y方向）具有可調變之光栅週期。藉此，當應用該晶體於 雷射產生系統時，雖然整個准相位匹配非線性光學單一 晶體維持於一固定溫度，但可藉由橫向（亦即沿該第二或 X方向）移動該晶體而選擇一最適當之光柵週期，藉此可 同時滿足兩光栅區之准相位匹配條件，進而達到波長連 續可調之目的。另外，亦可藉由調變晶體溫度，以達到 _ 更廣範圍之波長可調雷射。 本案得由熟悉本技術之人士任施匠思而為諸般修 飾，然皆不脫如附申請專利範圍所欲保護者。 «Page 25 1225948 V. Description of the invention (17) The design, principle, and application of the temperature control furnace 407, etc. are also similar to the components shown in the fifth figure ', so they will not be described again. As mentioned above, the grating design of the quasi-phase-matching nonlinear optical monolithic crystal in this case includes a single-period grating region and a sector grating region, where the sector grating region is in the lateral direction (that is, along the second or y direction). With adjustable grating period. Thus, when the crystal is applied to a laser generation system, although the entire quasi-phase-matching nonlinear optical single crystal is maintained at a fixed temperature, the crystal can be moved by moving the crystal laterally (that is, in the second or X direction). A most suitable grating period is selected so that the quasi-phase matching conditions of the two grating regions can be satisfied at the same time, and the purpose of continuously adjusting the wavelength can be achieved. In addition, you can adjust the crystal temperature to achieve a wider range of wavelength-tunable lasers. This case may be modified by anyone who is familiar with the technology, but none of them can be protected as attached to the scope of patent application. «
第26頁 1225948 圖式簡單說明 第一圖（A):係為習知技術之單週期准相位匹配非線性光 學晶體。 第一圖（B):係為另一習知技術之縱向串接雙週期准相位 匹配非線性光學晶體。 第二圖：係為本案准相位匹配非線性光學單一晶體之第一 較佳實施例示意圖。 第三圖：係為本案准相位匹配非線性光學單一晶體之另一 較佳實施例示意圖。 第四圖：係為本案雷射產生裝置之第一較佳實施例示意 圖，其中該雷射產生裝置未使用共振反射鏡組。 第五圖：係為本案雷射產生裝置之第二較佳實施例示意 圖，其中該晶體兩側具有二共振反射鏡。 第六圖：係為本案雷射產生裝置之第三較佳實施例示意 圖，其中該晶體兩端面鍍有二光學薄膜。 第七圖：係為本案雷射產生裝置之第四較佳實施例示意 圖。Page 26 1225948 Brief description of the diagram The first diagram (A): a single-cycle quasi-phase-matching nonlinear optical crystal of conventional technology. The first figure (B) is a longitudinally-connected double-period quasi-phase-matched nonlinear optical crystal of another conventional technique. The second figure is a schematic diagram of the first preferred embodiment of the quasi-phase-matching nonlinear optical single crystal of this case. The third figure is a schematic diagram of another preferred embodiment of the quasi-phase-matching nonlinear optical single crystal of this case. The fourth figure is a schematic diagram of the first preferred embodiment of the laser generating device in this case, wherein the laser generating device does not use a resonance mirror group. Fig. 5 is a schematic diagram of a second preferred embodiment of the laser generating device of the present invention, in which two sides of the crystal have two resonance mirrors. Fig. 6 is a schematic diagram of the third preferred embodiment of the laser generating device of the present invention, in which two ends of the crystal are plated with two optical films. Fig. 7 is a schematic diagram of a fourth preferred embodiment of the laser generating device of the present invention.
II
第27頁Page 27
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