1363178 [0001] [0002] [0003] [0004] 097101939 100年.12月12日修正钥 發明說明： 【發明所屬之技術領域】 本發明涉及一種感測器，尤其涉及一種折射率敏感之感 測器。 [先前技術] 由於具有獨特之光子禁帶（Photonic Band Gap)效應 ’光子晶體（Photonic Crystals)為設計微型折射率 敏感之感測器件提供了新之平臺。近幾年，基於光子晶 體設計之微型折射率敏感之感測器相繼問世，由於這種 感測器有較高之微腔諧振品質因素（high-Q mi-crocavity)和很小之傳感面積（每10μπι2之傳感面積 只要求被測重之樣本為1 f L )’因此該種感測器可用於痕 量樣品之測量。 請參閱J.Topol’ ancik等人之 “Fluid detection with photonic crystal-based multichannel waveguides" (Applied Physics Let- ters. 82, 1 143-1145(20 03))。J. Topol，ancik等人 設計之光子晶體波導結構之感測器可探測到之折射率變 化為0 · 2，此種感測器對折射率之解析度並不高。 E. Chow 等人於 “ultracompact biochemical sensor built with two-dimensional photonic crystal microcavity” (Optic Letters 29，1093 -1095(2004)(中提出了另一種感測器結構，其 採用·一維光子晶體微腔結構進行折射率之測量，折射率 之測量範圍可達到1. 0到1· 5。然而此種感測器中光線之 表單编號A0101 第4頁/共17頁 1003459944-0 1363178 [0005] [0006] [0007] 100年.12月12日接正—f 透過率很低，並且其測量精度不夠高，只能精確到0. 〇〇2 ’靈敏度也不高’只能達到200nin/RIU，其中RIU指單位 折射率（Refractive Index unit)。 【發明内容】 有寥於此’有必要提供一種具有更高透光率及測量精度 之折射率感測器。 一種折射率感測器，其包括光源、光子晶體微腔結構及 感測器，該光子晶體微腔結構包括晶體層及大量形成於 該晶體層並規則排列之孔，其中一個孔之直徑與其他孔 之直徑不同從而構成一諧振腔，該諧振腔相對之兩侧具 有線缺陷，該線缺陷分別構成第一波導與第二波導，該 第一波導及第二波導與該諧振腔之間分別具有數個孔， 該光源設置於該第一波導之入射端，該感測器設置於該 第二波導之出射端。 該折射率感測器中，第一波導及第二波導之設置使得光 線之透過率可提升到40%到70%，而且傳感器具有較高之 測量精度，可檢測折射率〇. 〇〇1之變化。可檢測折射率之 範圍較大，可從1. 0適用到1. 6。感測器之靈敏度達到 330nm/RIU 。 [0008] 097101939 【實施方式】 參閱圖1及圖2，第一實施例之光子晶體微腔結構1〇〇包括 基底104及晶體層10，晶體層丨〇形成於基底104上《晶體 層10之晶格常數為a，晶體層10之厚度為0. 4a〜〇. 7a，本 實施例優選為〇. 6a。晶體層10之材質可選用Si、GaAs或 GaA1 As。本實施例當中’晶體層1 0為GaA1 As，其晶格常 第5買/共I7頁 表單编號A0101 1003459944-0 1363178 100年12月12日按正頁 數為440奈米。晶體層1〇 一般通過磊晶生長形成於基體 104上，因此基體104適於磊晶生長晶體層10即可，例如1363178 [0001] [0003] [0003] [0004] 097101939 100. December 12th revised key invention description: [Technical Field] The present invention relates to a sensor, and more particularly to a refractive index sensitive sensing Device. [Prior Art] Due to the unique Photonic Band Gap effect, Photonic Crystals provide a new platform for designing miniature refractive index sensitive sensing devices. In recent years, micro-refractive-sensitive sensors based on photonic crystal design have been successively introduced, because of the high-Q mi-crocavity and small sensing area of this sensor. (The sensing area per 10μπι2 requires only 1 f L of the sample to be measured.) Therefore, this type of sensor can be used for the measurement of trace samples. See J. Topol' ancik et al., "Fluid detection with photonic crystal-based multichannel waveguides" (Applied Physics Let- ters. 82, 1 143-1145 (20 03)). J. Topol, ancik et al. The sensor of the crystal waveguide structure can detect a refractive index change of 0 · 2, and the resolution of the refractive index of such a sensor is not high. E. Chow et al. in "ultracompact biochemical sensor built with two-dimensional photonic Crystal microcavity" (Optic Letters 29, 1093 -1095 (2004) (another sensor structure is proposed, which uses a one-dimensional photonic crystal microcavity structure to measure the refractive index, and the refractive index can be measured within a range of 1. 0 to 1. 5. However, the form number of the light in this sensor is A0101. Page 4 of 17 page 1003459944-0 1363178 [0005] [0006] [0007] 100 years. December 12th is positive - f The transmittance is very low, and the measurement accuracy is not high enough, and can only be accurate to 0. 〇〇2 'sensitivity is not high' can only reach 200nin/RIU, where RIU refers to the refractive index unit (Refractive Index unit). There is a need for this A refractive index sensor having higher transmittance and measurement accuracy. A refractive index sensor comprising a light source, a photonic crystal microcavity structure and a sensor, the photonic crystal microcavity structure comprising a crystal layer and a plurality of a hole formed in the crystal layer and regularly arranged, wherein a diameter of one hole is different from a diameter of the other holes to form a resonant cavity having a line defect on opposite sides thereof, the line defect respectively forming the first waveguide and the second a waveguide, the first waveguide and the second waveguide and the resonant cavity respectively have a plurality of holes, the light source is disposed at an incident end of the first waveguide, and the sensor is disposed at an exit end of the second waveguide. In the rate sensor, the first waveguide and the second waveguide are arranged such that the transmittance of the light can be increased to 40% to 70%, and the sensor has a high measurement accuracy, and the change of the refractive index 〇. 〇〇1 can be detected. The range of the detectable refractive index is large, and can be applied from 1.0 to 1.6. The sensitivity of the sensor reaches 330 nm/RIU. [0008] 097101939 [Embodiment] Referring to FIG. 1 and FIG. 2, the first embodiment Photonic crystal The body of the microcavity structure 1 includes a substrate 104 and a crystal layer 10, and a crystal layer is formed on the substrate 104. The crystal layer 10 has a lattice constant a, and the crystal layer 10 has a thickness of 0. 4a~〇. 7a, The embodiment is preferably 〇. 6a. The material of the crystal layer 10 may be Si, GaAs or GaA1 As. In the present embodiment, the crystal layer 10 is GaA1 As, and its lattice is often 5th buy/total I7 page. Form No. A0101 1003459944-0 1363178 On December 12, 100, the number of pages is 440 nm. The crystal layer 1〇 is generally formed on the substrate 104 by epitaxial growth, so that the substrate 104 is suitable for epitaxial growth of the crystal layer 10, for example,
對於GaAs或GaAlAs材質之晶體層1〇，可選用GaAs、GaN 作為基底104。對於Si晶體層，可選用Si0作為基底1〇4 〇 [0009] 晶體層10内形成有大量孔1〇2。孔102可採用電子束微影 或反應性離子束蝕刻形成。本實施中，孔1〇2呈圓柱形， 當然孔102還可為其他形狀。孔1〇2排列成，依次記為 第1、2、3.....m行，每行具有η個孔102 ’依次記為第 1、2、3.....η個孔。其中m與η為14到18之間之整數。 本實施例令，孔1G2排列成17行，每行具有17個孔1〇2 ^ 孔102之直徑為〇.3a〜0.5a，本實施例當中，孔1〇2之直 徑為0. 36a。 [0010] 每行孔102之中心連線相异平行，同一行内之孔1〇2為等 間距排列，每相鄰之兩行孔102之間交錯排列，從而所有 之孔10 2構成三角形排列。以第1行第1、2個孔1〇 2與第2 行第1個孔102為例’第2行之第1個孔1〇2位於第1行第1 ' 2個孔102連線之中線上，從而第丨行第丨、2個孔1〇2與 第2行第1個孔102構成一三角形，優選地，此三角形為等 邊三角形。 [0011] 第i行第j個扎102之直徑與其他孔1〇2之直徑不同從而構 成一諧振腔12，其中i<i<m , 1<：|<η。優選地，i為最靠 近m/2之整數，j為最靠近〇/2之整數。諧振腔12之直徑 可為0. 5a到0. 6a。本實施例當中，其為〇 55a。 097101939 表單編號A0101 第6頁/共π頁 1003459944-0 1363178 •100%..12月12日梭正，頁 [0012]第i行之孔102中’諧振腔12兩侧各保留有k個孔102， l<k<6，而其餘的孔102被去除，或者說此處並未形成有 孔102，從而於諧振腔12兩側之晶體層1〇内分別形成兩個 線缺陷’兩個線缺陷分別構成第一波導14與第二波導16 »第一波導14及第二波導16均與諧振腔12之間隔有k個孔 102，本實施例中k = 3。孔102之直徑以及諧振腔12之直 徑發生改變時，諳振腔12之諧振波長會隨之發生改變。 [〇〇13] 參間圖3，本技術方案實施例之折射率感測器200包括光 源20、光子晶體微腔結構100及感測器22。光源20靠近 第一波導14之入射端142設置’感測器22靠近第二波導 16之出射端162設置。 [0014] 光源20可為發光二極體或者二極體鐳射器。光源20所發 射出之光線之波長處於諧振腔12之諧振波長之間即可。 例如根據上述實施例之光子晶體微腔結構100，可選用波 長於1800奈米到1830奈米之間之發光二極體或者二極體 鐳射器。 [0015] 感測器22用於感測從光源20發出並經過第一波導14、諧 振腔12及第二波導16後之光。由於光源20之波長處於紅 外波段，因此感測器22須能感測紅外波段之光波長，例 如感測器2 2可選用氧化鉛-硫化鉛光電陰極攝像管或者 InGaAs紅外探測器。感測器22可與外部之光譜裝置相連 ，從而可於外部之光譜裝置上觀察檢測結果。 [〇〇16] 本實施例之折射率感測器200中，光源20發出之光線經過 光子晶體微腔結構1〇〇之諧振作用後到達感測器22。而光 097101939 表單編號A0101 第7頁/共17頁 1003459944-0 1363178 100年.12月12日梭正替‘頁 線之波長於諧振之過程中會發生之變化。光線波長之變 化幅度與孔102仲介質之折射率相關。 [00Π] 參閱圖4，其為採用具有不同折射率之樣品注入到孔102 中進行測試之結果示意圖。如，將具有不同折射率之石夕 樹脂注射到光子晶體微腔結構100之表面，石夕樹脂之厚度 為200微米到500微米之間。碎樹脂會渗透到孔102及請 振腔12中。矽樹脂之折射率從1. 446變化到丨.450，變化 增量為0. 0 01。每個樣品測量完成後’將感測器2 〇〇放到 丙酮及異丙醇中漂洗並烘乾，然後進行下一次之測試。 從圖4中可看到，隨被測試樣品折射率之增加，證振波長 之之變化量也增加。參閱圖5，測量折射率範圍於1 〇到 .1. 6之間之樣品’將測量試樣品之折射率n與譜振波長之 漂移量△又繪於同一直角座標系中’本實施例中測量採 用之樣品為：折射率接近於1之空氣、折射率為1 1之液 體二氧化碳、折射率為1. 333之水、折射率為丨.36之丙 酮、折射率為1. 36之丙酮、折射率為1. 46之熔化之酒精 、折射率為1.49之80%之糖溶液、及折射率為丨53之氣 化鈉溶液。可看出諧振波長之漂移量△ λ與被測試樣品 之折射率之間呈良好之線性關係，即，折射率每增加 0. 001 ’諧振波長變大〇· 33奈米。本實施例之感測器之 靈敏度為330nm/RIU。 [0018] 本實施例之折射率感測器200中，通過光子晶體微腔結構 100中孔102之直徑、諧振腔12之直徑參數之選擇，及第 一波導14與第二波導16之設置，使得光線之透過率可提 升到40%到70%。而且諧振波長之漂移量△又與折射率變 097101939 表單编號A0101 1003459944-0 1363178 [100年.12月12日修正替換頁 化Δη之間之數值比達到33〇nm/RIU，使該折射率感測器 2 0 0具有較间之測i精度，可測量折射率G。Q i之變化。 當測試未知折射率之樣品時，根據檢測到之諧振波長即 可得到被測試樣品之折射率，且具有較大之折射率測量 範圍，吁達到1. 0到1. 6。 [0019] 综上所述，本發明確已符合發明專利之要件，遂依法提 出專利申清。惟，以上所述者僅為本發明之較佳實施方 式，自不能以此限制本案之申請專利範圍。舉凡熟悉本 案技藝之人士援依本發明之精神所作之等效修飾或變化 ，皆應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 [0020] 圖1係本技術方案第一實施例之折射率感測器之光子晶體 微腔結構示意圖。 [0021] 圖2係圖1沿II-II線之剖面示意圖。 [0022] 圖3係本技術方案實施例提供之折射率感測器示意圖。 [0023] 圖4係不同折射率之樣品諧振光譜示意圖。 [0024] 圖5係諧振波長之變化與折射率之間之關係曲線圖。 【主要元件符號說明】 [0025] 微腔結構：1〇〇 [0026] 基底：104 [0027] 晶體層：10 [0028] 孔：102 097101939 表單編號A0101 第9頁/共17頁 1003459944-0 1363178 100年.12月12日梭正替換頁 [0029] 諧振腔：12 ’ [0030] 第一波導：1 4 [0031] 第二波導：16 [0032] 感測器：200 [0033] 入射端：142 [0034] 出射端：162 [0035] 光源：20 [0036] 感測器：22 097101939 表單编號A0101 第10頁/共17頁 1003459944-0For the crystal layer of GaAs or GaAlAs material, GaAs or GaN may be used as the substrate 104. For the Si crystal layer, Si0 can be used as the substrate 1〇4 〇 [0009] A large number of holes 1〇2 are formed in the crystal layer 10. The apertures 102 can be formed using electron beam lithography or reactive ion beam etching. In the present embodiment, the hole 1〇2 has a cylindrical shape, and of course the hole 102 may have other shapes. The holes 1〇2 are arranged in order as the first, second, and third....m rows, and each row has n holes 102' which are sequentially referred to as first, second, third, ..., n holes. Wherein m and η are integers between 14 and 18. The diameter of the hole 1〇2 is 0.33a. In this embodiment, the hole 1G2 is arranged in a row of 17 holes, each row having 17 holes 1〇2 ^ The diameter of the hole 102 is 〇.3a~0.5a. [0010] The center lines of each row of holes 102 are parallel, and the holes 1〇2 in the same row are arranged at equal intervals, and the adjacent two rows of holes 102 are staggered so that all the holes 10 2 form a triangular arrangement. In the first row, the first and second holes 1〇2 and the second row and the first hole 102 are taken as an example. The first hole 1〇2 of the second row is located in the first row and the first 'two holes 102. The third line, the second hole 1〇2, and the second row first hole 102 form a triangle. Preferably, the triangle is an equilateral triangle. [0011] The diameter of the jth row 102 of the i-th row is different from the diameter of the other holes 1〇2 to constitute a resonant cavity 12, where i<i<m, 1<:|< Preferably, i is an integer closest to m/2, and j is an integer closest to 〇/2. 5a至0. 6a。 The diameter of the resonant cavity 12 may be 0. 5a to 0. 6a. In the present embodiment, it is 〇 55a. 097101939 Form No. A0101 Page 6 / Total π Page 1003459944-0 1363178 • 100%.. December 12th Shuttle, page [0012] Hole 102 of the ith row, 'K holes are reserved on both sides of the cavity 12 102, l < k < 6, while the remaining holes 102 are removed, or holes 102 are not formed here, thereby forming two line defects 'two lines respectively in the crystal layer 1 两侧 on both sides of the cavity 12 The defects respectively constitute the first waveguide 14 and the second waveguide 16 . The first waveguide 14 and the second waveguide 16 are spaced apart from the resonant cavity 12 by k holes 102, which is k = 3 in this embodiment. When the diameter of the hole 102 and the diameter of the cavity 12 are changed, the resonant wavelength of the oscillating chamber 12 changes. [〇〇13] Referring to FIG. 3, the refractive index sensor 200 of the embodiment of the present technical solution includes a light source 20, a photonic crystal microcavity structure 100, and a sensor 22. The light source 20 is disposed adjacent to the incident end 142 of the first waveguide 14 and the sensor 22 is disposed adjacent the exit end 162 of the second waveguide 16. [0014] The light source 20 can be a light emitting diode or a diode laser. The wavelength of the light emitted by the light source 20 may be between the resonant wavelengths of the resonant cavity 12. For example, according to the photonic crystal microcavity structure 100 of the above embodiment, a light-emitting diode or a diode laser having a wavelength of between 1800 nm and 1830 nm can be selected. [0015] The sensor 22 is for sensing light emitted from the light source 20 and passing through the first waveguide 14, the resonant cavity 12, and the second waveguide 16. Since the wavelength of the light source 20 is in the infrared band, the sensor 22 must be capable of sensing the wavelength of light in the infrared band. For example, the sensor 2 2 may be a lead oxide-sulfurized lead photocathode camera or an InGaAs infrared detector. The sensor 22 can be coupled to an external spectral device so that the detection results can be viewed on an external spectral device. [〇〇16] In the refractive index sensor 200 of the present embodiment, the light emitted from the light source 20 reaches the sensor 22 after the resonance of the photonic crystal microcavity structure 1〇〇. And light 097101939 Form No. A0101 Page 7 of 17 1003459944-0 1363178 100 years. On December 12th, the shuttle will replace the wavelength of the page line in the process of resonance. The magnitude of the change in the wavelength of the light is related to the refractive index of the secondary medium of the pores 102. [00Π] Referring to FIG. 4, it is a schematic diagram of the results of testing with a sample having a different refractive index injected into the hole 102. For example, a ceramsite resin having a different refractive index is injected onto the surface of the photonic crystal microcavity structure 100, and the thickness of the lithium resin is between 200 μm and 500 μm. The broken resin penetrates into the hole 102 and the vibration chamber 12. The refractive index of the resin is changed from 1.446 to 丨.450, and the increment is 0. 0 01. After each sample is measured, the sensor 2 is rinsed and dried in acetone and isopropanol, and the next test is performed. As can be seen from Figure 4, as the refractive index of the sample being tested increases, the amount of change in the proof wavelength also increases. Referring to FIG. 5, a sample having a refractive index ranging from 1 〇 to .1.6 is measured. 'The refractive index n of the measured test sample and the drift amount Δ of the spectral wavelength are plotted in the same rectangular coordinate system'. In this embodiment The sample used for the measurement is: air having a refractive index close to 1, air carbon dioxide having a refractive index of 1, a water having a refractive index of 1.333, acetone having a refractive index of 丨36, and acetone having a refractive index of 1.36. The melted alcohol having a refractive index of 1.46, a sugar solution having a refractive index of 1.49 and 80%, and a vaporized sodium solution having a refractive index of 丨53. It can be seen that there is a good linear relationship between the drift amount Δ λ of the resonance wavelength and the refractive index of the sample to be tested, that is, the resonance wavelength becomes larger at every increase of the refractive index of 0.001·33 nm. The sensitivity of the sensor of this embodiment is 330 nm / RIU. [0018] In the refractive index sensor 200 of the present embodiment, the diameter of the hole 102 in the photonic crystal microcavity structure 100, the selection of the diameter parameter of the resonant cavity 12, and the arrangement of the first waveguide 14 and the second waveguide 16 are The light transmission rate can be increased to 40% to 70%. Moreover, the drift amount Δ of the resonance wavelength is again proportional to the refractive index change 097101939 Form No. A0101 1003459944-0 1363178 [100 years. December 12th correction replacement page Δη is 33 〇nm / RIU, so that the refractive index The sensor 200 has a relatively high accuracy, and the refractive index G can be measured. The change of Q i. 0至1.6。 When the sample of the sample having an unknown refractive index, according to the detected resonant wavelength, the refractive index of the sample to be tested, and a larger refractive index measurement range, appealing to 1.0 to 1.6. [0019] In summary, the present invention has indeed met the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims. BRIEF DESCRIPTION OF THE DRAWINGS [0020] FIG. 1 is a schematic view showing the structure of a photonic crystal microcavity of a refractive index sensor according to a first embodiment of the present technical solution. 2 is a schematic cross-sectional view taken along line II-II of FIG. 1. [0022] FIG. 3 is a schematic diagram of a refractive index sensor provided by an embodiment of the present technical solution. 4 is a schematic diagram of a resonance spectrum of a sample having different refractive indices. [0024] FIG. 5 is a graph showing a relationship between a change in a resonant wavelength and a refractive index. [Major component symbol description] [0025] Microcavity structure: 1 〇〇 [0026] Substrate: 104 [0027] Crystal layer: 10 [0028] Hole: 102 097101939 Form No. A0101 Page 9 of 17 1003459944-0 1363178 100 years. December 12th Shuttle replacement page [0029] Resonant cavity: 12 ' [0030] First waveguide: 1 4 [0031] Second waveguide: 16 [0032] Sensor: 200 [0033] Incident end: 142 [0034] Exit end: 162 [0035] Light source: 20 [0036] Sensor: 22 097101939 Form number A0101 Page 10 of 17 1003459944-0