!2796〇6 九、發明說明： 【發明所屬之技術領域】 本發⑽有關於—種自動對焦之光纖式光學同調斷 層掃描之方法及《置’其主要係利用光纖式Ga並配人自 動對焦單元，以供可以同時量測單層被測物體的折射^及 厚度’以有效降低由被測物體或待測平移台所造成之量測 上之誤差。!2796〇6 IX. Description of the invention: [Technical field of the invention] The present invention (10) relates to a method for optical-optical optical coherence tomography of autofocus and "mainly using fiber-optic Ga and equipped with autofocus" The unit is configured to simultaneously measure the refraction and thickness of the single-layer object to be measured to effectively reduce the measurement error caused by the object to be tested or the translation stage to be tested.
【先前技術】[Prior Art]
按，光學同調性斷層掃描術（〇ptical c〇herence Tomography，以下簡稱0CT)是近十年開始發展的影像技 術，其技術的前身為光學低同調性反射術（〇ptical Coherence Domain Referity，以下簡稱 〇CDR)，該 〇CDR 利用頻譜光源（broad band light source )在時間同調 (time coherence)上的特性，作為量測光纖破壞的工具， 其量測的解析度取決於光源的頻譜寬度，相較於〇CDR，〇CT 結合0CDR縱向解析度的技術，並利用透鏡的聚焦，提升 了系統的橫向解析度，藉著搭配三維的平移台之後，便可 對樣品進行整個結構的掃描。 0CT除了用在掃描樣品結構外，也被使用在量測樣本 折射率與厚度上。Tearney et al.利用0CT光程差的特性， 以追縱焦點偏移技術（track the focal length shift)量 得光學玻璃樣本以及生活樣本的折射率。Fukano和 Yamaguchi則以類似的方法，發展出同時量測樣本折射率 1279606 以及厚度的技術’並且以OCT結合共焦顯微鏡的技術增加 焦點偏移技術的準確度，他們結合0CT與共焦系統以增進 聚焦點位置之準確度並獲付較南之訊雜比。而Haruna et al·以特製的樣本台量測出樣本的厚度並探討相位折射率 (phase refractive index)和群體折射率（gr〇up refractive index)的不同。Ohmi et al·用相同之架構來 量測生物組織之折射率與厚度，由於生物組織之表面平坦 丨 度極差，故他們假設相位折射率相等於折射率。近來，羅 裕龍教授提出不需使用高精密度掃描平移台及控制器之 架構，並提出依簡化之訊號調變及解調變之方法。Nishi et al·提出可同時量測單層樣本之厚度及折射率之方法，其 ，參考平移放置於量侧目標之後。其具有藉由簡單之計算就 . 可獲得二維資料之優點。 而0CT之基本原理，如第十二圖所示，其係用光源(A) 投射出第一道光束（Al)後，再經由光纖耦合器〔c〇叩ler〕 > (B)分成為第二道光束（A2)及第三道光束（A3)，其中第二 道光束（A2)經由掃描平移台（(：）之反射鏡（C1)予以反射作 為掃描時之參考光線，而第三道光束⑽則成為待測平移 台（D)上待測物體（D1)之探测光線，以供可以穿過人體之 皮膚、組織或其他待測物體（D1)，由於穿透皮膚、組織之 待測物體⑽的探測光線於光線反射回來的訊號會有時 間上的延遲，經與參考光線進行比對之後，透過光接受器 〔Photodeteetor〕⑻將光訊賴變為電訊號，並經過處 1279606 理器〔A/D Converter〕（F)分析該訊號，就可在顯示單元 (G)上得到待測物體（D1)的影像及相關資訊，而上述各元 件同時係經由一控制單元（H)予以控制。,ptical c〇herence Tomography (hereinafter referred to as 0CT) is an imaging technique that has been developed in the past decade. Its predecessor is optical low-coherence reflex (〇ptical Coherence Domain Referity, hereinafter referred to as 〇CDR), which uses the characteristics of the time band coherence of the broad band light source as a tool for measuring fiber damage. The resolution of the measurement depends on the spectral width of the source. The 〇 CDR, 〇CT combined with the 0CDR longitudinal resolution technique, and the focus of the lens is used to enhance the lateral resolution of the system. By matching the three-dimensional translation stage, the entire structure of the sample can be scanned. In addition to scanning the sample structure, 0CT is also used to measure the refractive index and thickness of the sample. Tearney et al. used the characteristics of the 0CT optical path difference to track the refractive index of the optical glass sample and the living sample by tracking the focal length shift. Fukano and Yamaguchi developed a technique for simultaneously measuring the refractive index of the sample 1279606 and the thickness in a similar way, and increased the accuracy of the focus shift technique by the technique of OCT combined with confocal microscopy. They combined the 0CT and confocal systems to enhance The accuracy of the focus point position is paid to the south of the signal ratio. Haruna et al. measured the thickness of the sample with a special sample size and explored the difference between the phase refractive index and the gr〇up refractive index. Ohmi et al. used the same architecture to measure the refractive index and thickness of biological tissues. Since the surface flatness of biological tissues is extremely poor, they assume that the phase index is equal to the refractive index. Recently, Professor Luo Yulong proposed not to use the architecture of high-precision scanning translation stage and controller, and proposed a simplified signal modulation and demodulation method. Nishi et al. proposed a method for simultaneously measuring the thickness and refractive index of a single-layer sample, which is placed after the translational reference target. It has the advantage of obtaining two-dimensional data by simple calculation. The basic principle of 0CT, as shown in Figure 12, is to use the light source (A) to project the first beam (Al), and then through the fiber coupler [c〇叩ler] > (B) a second beam (A2) and a third beam (A3), wherein the second beam (A2) is reflected by the scanning translation stage ((:) mirror (C1) as a reference light for scanning, and the third The beam (10) becomes the detection light of the object to be tested (D1) on the translation stage (D) to be tested, so that it can pass through the skin, tissue or other object to be tested (D1) of the human body, due to penetration of the skin and tissue. The signal detected by the object (10) is delayed by the light reflected from the light. After comparison with the reference light, the optical receiver is turned into a signal through a photoreceiver (8), and passes through 1279606. (A/D Converter) (F) analyzes the signal to obtain the image of the object to be tested (D1) and related information on the display unit (G), and the above components are simultaneously provided via a control unit (H) control.
其中光接受器（E)獲得探測光線及參考光線的訊號， 其只有在光程差小於同調長度的情況下反射光才能產生 干涉，也就是說只有與參考光線幾乎相等的反射光訊號才 能夠被分辨出來’ 0CT即是以此原理將待測物體（μ)的内 部特性層層解析出來，因此，光源（A)的同調長度即為光 學同調性斷層攝影術的縱向空間解析度，且其決定於光源 (A)的頻寬。 ^ 經利用Swanson et al·提出之藉由等速移動掃插平移 台產生的督卜勒（doppler)頻率平移的優點，此方法提供 了高靈敏度、高速且高解析度的量測。為了探測干 的波包（envelope)，應用如第十三圖所示之簡單的二調= 技術以作波包的探測。 e t OCT所產生的干涉訊说（I)可表示成方程式（一 Kc = ^〇cos(2^〇(Lr - Ls)) · Q一） 假設掃描平移台（c)移動速度為（V)，因此我們 方程式（一）如下： 罵The light receiver (E) obtains the signal of the detecting light and the reference light, and the reflected light can only interfere when the optical path difference is less than the coherence length, that is, only the reflected light signal which is almost equal to the reference light can be It is distinguished by the fact that '0CT is the inner characteristic layer of the object (μ) to be measured. Therefore, the coherence length of the light source (A) is the longitudinal spatial resolution of the optical tonal tomography, and the decision is made. The bandwidth of the light source (A). ^ This method provides high sensitivity, high speed and high resolution measurements by using the advantage of Doppler frequency shifting produced by Swanson et al. by a constant velocity moving sweeping translation stage. In order to detect the dry envelope, a simple two-tone = technique as shown in Fig. 13 is applied for the detection of the wave packet. The interferogram (I) generated by et OCT can be expressed as an equation (a Kc = ^〇cos(2^〇(Lr - Ls)) · Q a) Assume that the scanning translation stage (c) moves at a speed of (V), So our equation (1) is as follows:
Kc = - Ls)) (二） 將心以帶入上式，可改寫為·· 7 ^ = 7。eos〇〆一彡） (多）為初始相位 其中（％)為都普勒角頻率4冰/又。 7 1279606 ^ 47rLsU〇 〇 經過一帶通濾波器（II)後，接著，我們把此訊號互 乘，訊號轉變為： ’ac - ’〇 cos 一 #) (四） 然後，我們藉由三角關係c〇s2(你-妁=卜sin2(⑽-妁改寫 方程式（四），將其帶入一低通濾波器（12)。因此方程式（四） 轉變為： • l2ac=I0 (五） 因此，我們可得到待測物體（D1)的特性訊號（/〇)。 如第十四圖所示，係為將訊號調變技術流程整理後之 不意圖，其橫軸係為時間（ms)，而縱轴則為電壓（mv)，其 '變化幅度則呈一 S型曲線（s-Curve)。 、 以0CT量測折射率的技術發展至此，已可成功的用來 1測單層、多層或是生物活體樣本，然而為了減少量測上 馨 的誤差，多以閉迴路伺服控制平移台來做為樣本平移台及 帚1¾ 然而此種平移台造價昂貴，增加oct商品化的不 易，因此在於使用效果上並不甚理想。 【發明内容】 菱此’本發明有鐘於習知之0CT於使用上具有諸多缺 點，因此本發明係在提供一種自動對焦之光纖式光學同調 斷層掃描之裝置，包括有：光源，其係可發射出第一道光 束；光纖耦合器，其係包括有第一、二光纖耦合器，而可 將4第道光束分為第二、三、四道光束，而第二道光束 8 1279606 • 則作為掃描時的參考點；掃描平移台，其係設有反射鏡， 而可將該第三道光束予以反射作為掃描時之參考光線；待 測平移台，其係可放置待測物體，藉以供第四道光束作為 探測時之探測光線；光接受器，其包括有第一、二光接受 器，其中第一光接受器係為獲得第三道光束及第四道光束 的干涉號’和探測第二道光束及第四道光束的干涉訊 號，而第二光接受器則為獲得第二道光束及第三道光速的 丨干涉訊號，和用來探測第二道光束及第三道光束的干涉訊 號，然後，將光訊號轉變為電訊號；處理器，其係可分析 光接受器所轉變之電訊號；顯示單元，其係可供接受處理 器之資料，而顯示出待測物體的影像及其相關資訊；自動 、對焦單元，其係設有DVD光學讀取頭，並係設有致動器控制 其上下移動，其内部則設有圓柱透鏡及物鏡，以供進行對 焦，又於DVD光學讀取頭上設有透孔，以供設入有光束準直 器；控制單元，其係可控制上述各單元構件之操作。 ►又本發明係在提供一種自動對焦之光纖式光學同調 斷層掃描之方法，係包括有下列之步驟： a、 待測物體置於待測平移台上； b、 光源發出第一道光束； c、 透過光纖耦合器分為第二、三、四道光束； d、 第二道光束作為掃描時的參考點； e、 第三道光束作為掃描時之參考光線； f、 第四道光束作為探測待測物體之探測光線·， 1279606 g、 移動DVD光學讀取頭自動進行對焦； h、 光接受器將干涉之光訊號轉變為電訊號； i、 處理器分析該電訊號； j、 顯示單元顯示出被測物體之影像及相關資訊； 本發明實施例確實具有下列之優點·· 1·本發明係可同時量測單層被測物體的折射率以及严 度。 予 2·本發明利用自動對焦單元，可有效降低震動上之影 響，以降低被測物體或待測平移台的輕微擾動造成之量 誤差。 里 '丨 3·本發明之造價低廉，可大幅降低製造之成本 【實施方法】 首先，請參閱第一圖，本發明之自動對焦之光纖式光 學同調斷層掃描之裝置，包括有： 光源（1)，其係可供發射出第一道光束（11)。 光纖耦合器（2)，其係包括有第一、二光纖輕合器 (21)、（22)，係可將該第一道光束（11)分為第二、三、四 道光束（12)、（13)、（14)，其中該第二道光束〇2)則作為 掃描時的參考點（15)。 掃描平移台（3)，其係設有反射鏡（31)，而可將該第 三道光束（13)予以反射作為掃描時之參考光線。 待測平移台（4)，其係可放置有人體皮膚、組織之待 測物體（41)，藉供第四道光束（14)作為探測待測平移台（4) 1279606 • 上待測物體（41)之探測光線。 光接受器（photodetector)(5)，其包括有第一、二光 接受器（51)、（52)，其中第一光接受器（51)係為獲得第三 道光束（13)及第四道光束（14)的干涉訊號，和探測第二道 光束（12)及第四道光束（14)的干涉訊號，而第二光接受器 (52)則為獲得第二道光束（12)及第三道光速（14)的干涉 訊號，和用來探測第二道光束（12)及第三道光束（13)的干 Φ 涉訊號，然後，再透過第一、二光接受器（51)、（52)將光 訊號轉變為電訊號。 處理器〔A/D Converter〕（6)，其係可分析第一、二 光接受器（51)、（52)所轉變之電訊號。 ， 顯示單元（7)，其係可供接受處理器（6)之資料，而顯 示出待測物體（41)的影像及其相關資訊。 自動對焦單元（8)，其係設有一 DVD光學讀取頭 〔Pick-up head〕（81)，由於 DVD 光學讀取頭〔Pick-up • head〕（81)為了讀取高密度之DVD光碟片，需要產生足夠 小的光點以便能照射到光碟片上的表面凹洞（pit)，並收 取該處的反射光，光由雷射二極體（Laser diode)發出， 被偏光分光器（PBS)反射後經過準直器以及物鏡後，形成 小光點照射到光碟片上的表面凹洞，而光由光碟片上的表 面反射後，經由物鏡、準直器與偏光分光器後，由光接收 器將其光能轉換成電能輸出，光碟機在運轉時會造成上下 晃動（wobble)以及偏心旋轉（runout)的運動，因此會造成 11 Ϊ279606 二取光碟片上資料上的嚴重錯誤，若要使光碟機能準確地 讀取=及寫入資料，讀取頭必須具有能非常準確地使光點 鎖在為料軌上，因此該DVD光學讀取頭（81)的伺服控制方 /土本上了以分為兩個部份·一為聚焦（focusing)，一為 循執（tracking)，但由於將自動聚焦與〇CT系統結合後， 考慮到活體組織的輕微擾動多屬上下之移動，雖然會有少 許的橫向偏移但相對上極為微+，因此以下只考慮縱向的 ⑩聚’、、、#伤，DVD光學讀取頭（81)在讀取光碟片上訊號之 ^必先上下移動物鏡（82)以尋找最佳位置，此即所謂的 聚焦偵測（focus search)，使聚焦光點能正確的聚焦於光 碟片上，因為在進行光學檢測時只需輕微的移動待測物， ，便會造成DVD光學讀取頭（81)偏離原聚焦點，造成資料讀 _取上的錯誤，所以可利用取得聚焦誤差訊號並經由外部伺 服控制電路回授到致動器〔actuator〕（83)上，來控制安 置在物鏡（82)上的致動器（83)，使其作即時的補償來進行 _ 重新對焦的工作。 又該DVD光學項取頭（81)的聚焦誤差的感測是利用像 散法（Astigmatic method)，如第二圖所示，其利用圓挺 透鏡（84)沿著正交轴方向有兩個不同的聚焦長度，在一個 轴向上會有折光（Bending)的能力，另一個方向不會有折 光的效果，而使穿過圓柱透鏡（84)的第四道光束（14)形成 像散的現象的特性，來做為聚焦感測的依據，當光點聚焦 於物鏡（82)的焦點時，此時反射回來的光線會在圓柱透鏡 12 1279606 .(84)的兩個聚焦線中間形成一正圓形的形狀；若有失焦 (defocus)情形發生，將會造成兩聚焦線沿著光軸偏移， 此時若將四分接受器（quad-detector)放置於最小彌散圓 (Least Confusion Circle)的位置上’則當光碟片（85)遠 離或靠進物鏡（82)系統時，會在四分接收器上形成相互垂 直的橢圓光點或是正圓形光點。 利用四個接收器單元所感受到光強度差異即可獲知 鲁 光碟片（85)偏移’正確聚焦位置的方向以及偏焦的距離大 小，將此聚焦誤差訊號加以放大並產生一推移線圈馬達的 動力，以改變物鏡（82)的位置，即可以達到聚焦錯誤修正 的目的。 當致動器（83)在做聚焦控制時，會驅動物鏡（82)做上 下運動，因此不論光碟片（85)遠離或是接近焦點時四像儀 會測出不同的電壓，此時我們以此訊號輸入伺服系統就可 將其作為自動聚焦控制的依據；且由於此聚焦誤差訊號的 外型類似英文字母中的s，故常稱其s型曲線（s_Curv二。 為了要與0CT系統結合，係在DVD光學讀取頭（81)上鑽一 透孔（86)，使0CT系統中用來探測待測物特性的光束準直 器〔Collimator〕⑽能通過其中，並使其附著於_ 學讀取頭⑻）上隨之上下運動’以達到自動聚焦的作用。 控制單元⑼，其係可供控制上述各單元構件之操作。 又本發明係為—種自動對焦之 掃描之方法’係利用上述自動對焦之光纖式光學同= 13 1279606 掃描之裝置進彳丨#、f 圖所 示〕： 叫測’則包括有下列之方法〔如第 ^、待測物體置於待測平移台上 體（41)置放於待财心"w ㈣料的待測物 方向的平移，使:=)上，待測平移台⑷可以做z 測物體（41)之_直移動。 丁人於将 b光源發出第一道光束··藉由控制單元 源⑴，發射出第-道光束⑼。 了控制先 C,透過光纖轉合器分為第二、三、四道光束：係可 經由光_合器⑵之第—、二光纖耦合器（21)、（22)將 -亥第道光束⑴）分為第二、三、四道光束 (⑷。 ^ d第一道光束作為掃描時的參考點：第二道光束（12) 係直接可作為掃描時的參考點（15)。 e、 第二道光束作為掃描時之參考光線：經由掃描平 移台（3)之反射鏡（31)，而可將該第三道光束（13)予以反 射作為掃描時之參考光線。 f、 第四道光束作為探測待測物體之探測光線：而第 四道光束（14)作為待測平移台上待測物體（41)之探測 光線，以供可以穿過人體之皮膚、組織或其他待測物體 (41) 〇 §、移動DVD光學讀取頭自動進行對焦：第四圖係為 待測平移台（4)上的光纖架設方式，該參考平面的表面與 1279606 -待測物體⑷）的上下表面各被^義為⑽，⑻和（Rs) 一步，使光穿透自動對鮮元⑻之光束準直器⑽，並 ^於X軸上的X。處，此_整_光學讀取頭⑻）使 焦於參考平面（）上，之後，蒋叙彡主 移動待測平移台（4)來記錄干 涉訊號的波包位置，兩波包分別定義為⑽和⑻〔如第五 圖所示〕’第mx轴移動待測平移台⑷，使待 物體（41)位於（Xs)處’二個解調變後之干涉訊號分別被 ❿定義為（Rs)’⑻和⑻〔如第六圖所示〕，因此，無論待 測平移台⑷如何移動’自動對焦單元⑻將永遠聚焦於參 考平面（R。）上。 將第五圖與第六圖的訊號以第二道光束（12)做校 •正^可整理出如第七圖所示，其中係定義（Δ7；)是峰值（s) ，與内間的時間差，而（ΔΓ0是峰值内與（ 尺）間的時間 差\因此’相對於（ΔΓι)與（ΔΓ0的峰值間的距離（△句與（轼） 可藉由下式個別求出： • Δί/ι=Δ?ιΧκ Δ^2-ΔΓ2χΚ (六） 1 (七） 其中（V)為掃描平移台（3)的掃描速度，且其需為定值。 因此，被測物體（41)的厚度（t)，和折射率（η)，將可 分別藉由下式求出： (八) (九） t = H-Ad2 和 15 1279606 ~ 係可以沿著χ軸移動並做掃描，以藉由簡單之數學運 算得到不同位置的樣本折射率與厚度。 子 又如第-圖所示，其中寬頻之光源⑴為捧裤光纖放 大器的自發性白光光源，其中心波長為1550nm，波寬為 37mn，同調長度估計為57_。自動對焦單元（8)為Acute Applied Technologies Inc.所製：DpD2〇6〇1，雷射二極 體波長為65Grm。自動對焦裝置之s曲線如第十四田圖所^。 • 經利用量測D263Τ之單層玻璃來測試系統的精準度， 其理論上之折射率和厚度各約為15116和146 5_。待 測平移台⑷之速度料125 _々1利用程式 控制待測平移台⑷產生震幅為5〇_及頻率丨i〇Hz到 ._z的擾動，峨測⑽統在不_振動鮮、相同振 .幅下的穩定性，可明顯的知道，被測物體⑷）之預估速度 k 1000到10000 //m/s非常大於待測平移台⑷之速度設 為125 W/s。因此，可以證明此系統位於具有震動環境 • 下之穩定性。 為了簡化起見，假設待测物體（41)之折射率為理論值 (1.5116)後，待測物體（41)之厚度可直接由其表面與底面 之干涉訊號之波包求出。其解調變訊號圖如第八圖所示。 明顯的，在待測平移台⑷具有10Hz震動下，待測物體⑹ 之表面與底面之干涉訊號之波包可被探測出。故測試該系 、先位於1G到1GG Hz的待測平移台⑷震動下之穩定性， 並將其誤差百分比曲線表示於第九圖所示。由測量出的結 1279606 果可看出此系統具有極高之精確性，在不同頻率下的誤差 皆約在0.4%下；然而值得注意的是，當頻率為4〇Hz時量 測出來的結果誤差明顯較大（1%)，此乃由於此頻率範圍位 於DVD光學讀取頭（8)的制動器（81)的共振頻率中，以導 致量測之誤差偏大。Kc = - Ls)) (2) Bring the mind into the above formula, which can be rewritten as ·· 7 ^ = 7. Eos〇〆一彡) (Multi) is the initial phase where (%) is the Doppler angle frequency of 4 ice/again. 7 1279606 ^ 47rLsU〇〇 After a bandpass filter (II), then we multiply this signal and the signal is converted to: 'ac - '〇cos a#) (4) Then we use the triangular relationship c〇 S2 (you-妁=Bu sin2((10)-妁 rewrite equation (4), bring it into a low-pass filter (12). So equation (4) is transformed into: • l2ac=I0 (five) Therefore, we can Obtain the characteristic signal (/〇) of the object to be tested (D1). As shown in Fig. 14, it is the intention to sort out the signal modulation technology flow, and the horizontal axis is time (ms), and the vertical axis Then it is the voltage (mv), and its 'variation amplitude is an S-curve. s-Curve. The technology of measuring the refractive index by 0CT has been developed to this point. It can be successfully used to test single layer, multi-layer or biological. In vivo samples, however, in order to reduce the error of the measurement, the closed-loop servo control translation stage is used as the sample translation stage and the 平移13⁄4. However, such a translation stage is expensive, and it is not easy to increase the oct commercialization, so the use effect is It is not ideal. [Summary of the Invention] The 0CT has many disadvantages in use, and therefore the present invention provides an apparatus for autofocus optical fiber tonal tomography, comprising: a light source, which emits a first beam; and a fiber coupler, including There are first and second fiber couplers, and the fourth beam can be divided into second, third and fourth beams, and the second beam 8 1279606 is used as a reference point for scanning; scanning translation stage, which is designed There is a mirror, and the third beam can be reflected as a reference light during scanning; the translation stage to be tested can be placed on the object to be tested, so that the fourth beam can be used as the detection light during detection; the light receiver The first light receiver is configured to obtain an interference signal of the third beam and the fourth beam and an interference signal for detecting the second beam and the fourth beam. The second photoreceiver is an interfering signal for obtaining a second beam and a third beam of light, and an interfering signal for detecting the second beam and the third beam, and then converting the optical signal into a telecommunication signal; The processor is configured to analyze the electrical signal converted by the optical receiver; the display unit is configured to receive the data of the processor, and display the image of the object to be tested and related information; the automatic, focusing unit, the system There is a DVD optical pickup with an actuator to control the movement up and down. The inside is provided with a cylindrical lens and an objective lens for focusing, and a through hole is provided on the DVD optical pickup for the purpose of setting A beam collimator; a control unit that controls the operation of each of the unit members. ► The present invention is directed to a method of optical fiber optical coherence tomography that includes autofocusing, including the following steps: a, to be tested The object is placed on the translation stage to be tested; b, the light source emits the first beam; c, is divided into the second, third, and fourth beams by the fiber coupler; d, the second beam serves as a reference point for scanning; e. The third beam is used as the reference light for scanning; f, the fourth beam is used as the detection light for detecting the object to be tested, 1279606 g, the moving DVD optical pickup automatically focuses; h, the light receiver will The optical signal is converted into a telecommunication signal; i. The processor analyzes the electrical signal; j. The display unit displays an image of the measured object and related information; the embodiment of the present invention has the following advantages: 1. The present invention is At the same time, the refractive index and severity of the single-layer object to be measured are measured. 2. The present invention utilizes an autofocus unit to effectively reduce the effects of vibration to reduce the amount of error caused by the slight disturbance of the object being measured or the translation stage to be tested.丨'丨3· The invention is low in cost and can greatly reduce the manufacturing cost. [Methods of Implementation] First, referring to the first figure, the apparatus for autofocus optical fiber tonal tomography of the present invention includes: a light source (1) ), which is used to emit the first beam (11). A fiber coupler (2) comprising first and second fiber light combiners (21), (22) for dividing the first beam (11) into second, third, and fourth beams (12) ), (13), (14), wherein the second beam 〇 2) is used as a reference point (15) during scanning. A scanning translation stage (3) is provided with a mirror (31) which can be reflected as a reference light for scanning. The translation stage (4) to be tested, which can be placed with the human skin and the object to be tested (41), and the fourth beam (14) is used as the detection of the translation stage to be tested (4) 1279606 • the object to be tested ( 41) Detecting light. a photodetector (5) comprising first and second light receivers (51), (52), wherein the first light receiver (51) is configured to obtain a third light beam (13) and a fourth The interfering signal of the beam (14) and the interfering signal for detecting the second beam (12) and the fourth beam (14), and the second photoreceiver (52) is for obtaining the second beam (12) and The third light velocity (14) interference signal, and the dry Φ signal used to detect the second light beam (12) and the third light beam (13), and then transmitted through the first and second light receivers (51) (52) Converting the optical signal into a telecommunication signal. The processor (A/D Converter) (6) is capable of analyzing the electrical signals converted by the first and second optical receivers (51) and (52). The display unit (7) is adapted to receive the data of the processor (6) and display the image of the object to be tested (41) and related information. The autofocus unit (8) is provided with a DVD optical pickup (81), and the DVD optical pickup (Pick-up head) (81) is for reading a high-density DVD. The film needs to generate a small enough spot to be able to illuminate the surface pit on the disc and collect the reflected light there. The light is emitted by the laser diode and is polarized by the splitter (PBS). After the reflection passes through the collimator and the objective lens, a small concave spot is formed on the surface concave surface of the optical disc, and the light is reflected by the surface on the optical disc, and then passed through the objective lens, the collimator and the polarizing beam splitter, and then the optical receiver Converting its light energy into electrical energy output, the optical disc drive will cause up and down wobble and eccentric rotation during operation, which will cause 11 Ϊ 279606 to take serious errors on the optical disc, in order to make the optical disc function Accurately reading = and writing data, the read head must have a very accurate lock on the track, so the servo control side of the DVD optical read head (81) is divided into For two parts (focusing), one is tracking, but because of the combination of autofocus and 〇CT system, considering that the slight disturbance of living tissue is mostly up and down, although there will be a little lateral offset, it is relatively slight. +, therefore, only the longitudinal 10's, ', and # injuries are considered in the following. The DVD optical pickup (81) must first move the objective lens (82) up and down to find the best position when reading the signal on the optical disc. This is called Focus search, so that the focused spot can be correctly focused on the disc, because only a slight movement of the object to be tested during optical inspection will cause the DVD optical pickup (81) to deviate from the original The focus point causes the data to read and take the error, so the focus error signal can be obtained and fed back to the actuator (83) via the external servo control circuit to control the placement on the objective lens (82). The actuator (83) is used for immediate compensation to perform the _ refocusing operation. Further, the sensing of the focus error of the DVD optical item take-up head (81) is performed by the astigmatism method, as shown in the second figure, which uses the rounded lens (84) to have two directions along the orthogonal axis. Different focusing lengths have the ability to bend in one axial direction, and the other direction does not have the effect of refraction, so that the fourth beam (14) passing through the cylindrical lens (84) forms astigmatism. The characteristic of the phenomenon is used as the basis of the focus sensing. When the spot is focused on the focus of the objective lens (82), the reflected light will form a light between the two focus lines of the cylindrical lens 12 1279606 . a perfectly circular shape; if defocus occurs, it will cause the two focal lines to shift along the optical axis. At this time, place the quad-detector on the least diffuse circle (Least Confusion). In the position of Circle), when the optical disc (85) is moved away from or into the objective lens (82) system, mutually perpendicular elliptical spots or right circular spots are formed on the quarter receiver. By using the difference in light intensity perceived by the four receiver units, the direction of the correct focus position and the distance of the focus can be obtained by the Luguang disc (85) offset, and the focus error signal is amplified to generate a power of the push coil motor. In order to change the position of the objective lens (82), the purpose of focus error correction can be achieved. When the actuator (83) is in focus control, it will drive the objective lens (82) to move up and down, so the camera will measure different voltages regardless of whether the disc (85) is far away or close to the focus. This signal input servo system can be used as the basis of auto focus control; and since the appearance of this focus error signal is similar to the s in the English alphabet, it is often called the s-curve curve (s_Curv II. In order to be combined with the 0CT system, A through hole (86) is drilled in the DVD optical pickup (81) so that a collimator (10) for detecting the characteristics of the object to be tested in the 0CT system can pass through and attach it to the _ Take the head (8)) and then move up and down 'to achieve the effect of auto focus. A control unit (9) is provided for controlling the operation of each of the above unit members. In addition, the present invention is a method for scanning an autofocus image by using the above-mentioned autofocus optical fiber optics and the device of the 13 13279606 scanning device. [If ^, the object to be tested is placed on the translation stage (41) of the object to be tested, placed in the direction of the object to be tested, and the translation stage (4) can be tested. Do z to measure the movement of the object (41). Ding people emit the first light beam from the b light source. · The first light beam (9) is emitted by the control unit source (1). The control first C is divided into the second, third and fourth beams through the fiber optic converter: the first beam can be transmitted through the first and second fiber couplers (21) and (22) of the optical coupler (2). (1)) Divided into second, third and fourth beams ((4). ^ d The first beam is used as the reference point for scanning: the second beam (12) is directly used as the reference point for scanning (15). The second light beam serves as a reference light for scanning: the third light beam (13) can be reflected as a reference light during scanning by scanning the mirror (31) of the translation stage (3). f, the fourth track The light beam is used as a detecting light for detecting the object to be tested: and the fourth light beam (14) is used as the detecting light of the object to be tested (41) on the translation stage to be tested, so as to pass through the skin, tissue or other object to be tested of the human body ( 41) 〇§, moving DVD optical pickup automatically focuses: the fourth picture is the fiber erection mode on the translation stage (4) to be tested, the surface of the reference plane and the upper and lower surfaces of 1279606 - the object to be tested (4) By the meaning of (10), (8) and (Rs) one step, the light penetrates automatically to the beam of the fresh element (8) Is ⑽, and the X-axis ^ X. At this point, the _ _ optical reading head (8) is focused on the reference plane (), after which, Jiang Xuyi mainly moves the translation stage (4) to record the wave packet position of the interference signal, and the two wave packets are respectively defined as (10) and (8) [as shown in the fifth figure] 'the mx axis moves the translation stage (4) to be tested, so that the object (41) is located at (Xs). The interference signals after the two demodulation changes are defined as (Rs). ) '(8) and (8) [as shown in Figure 6], therefore, no matter how the translation stage (4) to be tested moves, the autofocus unit (8) will always focus on the reference plane (R.). The signals of the fifth and sixth figures are corrected by the second beam (12). The positive image can be sorted out as shown in the seventh figure, where the definition (Δ7;) is the peak (s), and the inner The time difference, and (ΔΓ0 is the time difference between the peak and the (foot) \ hence 'the distance between (ΔΓι) and the peak of ΔΓ0 (the △ sentence and (轼) can be obtained by the following formula: • Δί/ ι=Δ?ιΧκ Δ^2-ΔΓ2χΚ (6) 1 (7) where (V) is the scanning speed of the scanning translation stage (3), and it needs to be a fixed value. Therefore, the thickness of the object to be measured (41) ( t), and the refractive index (η), can be obtained by the following equation: (8) (9) t = H-Ad2 and 15 1279606 ~ can be moved along the x-axis and scanned for simplicity The mathematical operation results in the refractive index and thickness of the sample at different positions. As shown in the first figure, the broadband source (1) is a spontaneous white light source of the trousers fiber amplifier with a center wavelength of 1550 nm and a wave width of 37 nm. The length is estimated to be 57_. The autofocus unit (8) is manufactured by Acute Applied Technologies Inc.: DpD2〇6〇1, laser diode The length is 65Grm. The s curve of the autofocus device is as shown in the fourteenth map. • The accuracy of the system is tested by measuring the single layer glass of D263, which theoretically has a refractive index and thickness of about 15116 and 146, respectively. 5_. The speed of the translation stage (4) to be tested 125 _ 々 1 using the program to control the translation stage (4) to generate a vibration amplitude of 5 〇 _ and the frequency 丨 i 〇 Hz to ._z disturbance, speculation (10) system is not _ vibration fresh The same vibration, the stability under the amplitude, it is obvious that the estimated speed of the measured object (4) is k 1000 to 10000 //m/s, which is much larger than the speed of the translation stage (4) to be measured, which is set to 125 W/s. It can be proved that the system is stable under vibration environment. For the sake of simplicity, assuming that the refractive index of the object to be tested (41) is the theoretical value (1.5116), the thickness of the object to be tested (41) can be directly The wave packet of the interference signal between the surface and the bottom surface is obtained. The demodulation signal diagram is as shown in the eighth figure. Obviously, the interference signal between the surface and the bottom surface of the object to be tested (6) under the 10 Hz vibration of the translation stage (4) to be tested The wave packet can be detected. Therefore, the system is tested at 1G to 1GG Hz. The stability of the translation stage (4) under vibration, and its error percentage curve is shown in Figure 9. From the measured junction 1279606, it can be seen that the system has extremely high accuracy, and the error at different frequencies is about At 0.4%; however, it is worth noting that the measured error is significantly larger (1%) when the frequency is 4 Hz, because this frequency range is located in the brake of the DVD optical pickup (8) ( In the resonance frequency of 81), the error causing the measurement is excessive.
經過應用結合自動對焦單元（8)之〇CT系統來做樣本 之折射率與厚度之量測，本發明使用D263T之玻璃作為實 驗時之待測物體（41)，其折射率和厚度各為丨5116和 150，，設定待測平移台⑷之每一脈衝所走之距離為2 且掃描速度為125_/s，控制㈣平移台⑷使其產生 有如震動雜訊之Η) Hz與5Q辦振幅之運動，則該待測物 體之兩掃描實驗訊號將由第―、二光錢印丨）、⑽接 收，並藉由第f道光束（12)來校正兩掃描訊號後，由第 矣⑻與（52)接收之兩組調變後之訊號個別 (△I、因此ΐ第十一圖’由第十圖可求出(ΔΤι)與 CM，因此’相物體⑹之相對映 可經由方程式⑷與（九）求出。 ，數11與七則 在OCT系、、先結合與不結合自動對焦 體⑹之折射率與厚度之量測結果如下表2)時，待測物After applying the CT system of the autofocus unit (8) to measure the refractive index and thickness of the sample, the present invention uses the glass of D263T as the object to be tested (41) during the experiment, and the refractive index and thickness thereof are each 丨5116 and 150, set the distance of each pulse of the translation stage (4) to be 2 and the scanning speed is 125_/s, and control (4) the translation stage (4) to generate vibration noise. Hz and 5Q amplitude For motion, the two scanning experiment signals of the object to be tested will be received by the first and second light money, and (10), and after the two scanning signals are corrected by the f-th beam (12), the second (8) and (52) are corrected. The received two sets of modulated signals are individually (△I, therefore, the eleventh figure' can be obtained from the tenth figure (ΔΤι) and CM, so the relative reflection of the 'phase object (6) can be obtained via equations (4) and (nine) ), the number of 11 and 7 in the OCT system, the first and the unbonded autofocus body (6) refractive index and thickness of the measurement results as shown in the following Table 2), the object to be tested
17 值仔注思的疋’由於待測平移台⑷震動（50_) ^若οα祕稀合自動對鱗元⑻時㈣統將紐 ，此乃因其震動之振幅大於該光源之同調長度，結合 動對焦單元（8)之〇CT系統在被測物體（41)資料上有極 好的一致性，即使選用較差之待測平移台（4)之精度及使 待測平移台（4)產生震動，折射率與厚度之實驗標準誤差 依然分別約在0· 024與〇·243_，此證明結合自動對焦裝 置（8)於OCT系統的確能有效降低因外界之震動造成的誤 差。 h、 光接受器將干涉之光訊號轉變為電訊號：該光接 受器（5)之第一光接受器（51)係可獲得第三道光束（13)及 第四道光束（14)的干涉訊號，和探測第二道光束（12)及第 四道光束（14)的干涉訊號，而第二光接受器（52)則為獲得 第二道光束（12)及第三道光速（14)的干涉訊號，和用來探 測第二道光束（12)及第三道光束（13)的干涉訊號，然後， 再透過第一、二光接受器（51)、（52)將光訊號轉變為電 訊號。 i、 處理器分析該電訊號：再經由處理器（61)分析第 一、二光接受器（51)、（52)所轉變之電訊號。 j、 顯示單元顯示出被測物體之影像及相關資訊·最 後則在顯示單元（62)上得到待測物體（41)的影像及相關 資訊。 【圖式簡單說明】 1279606 第一圖係為實施本發明之裝置示意圖。 第二圖係為本發明實施例像散法之示意圖。 第二圖係為本發明實施方法之步驟流程圖。 第四圖係為本發明之被測物體及參考平面之示意圖。 第五圖係為本發明第一、二光接受器接收χ。處訊號之示意 圖。 第六圖係為本發明第一、二光接受器接收Xs處訊號之示意17 valued thinking 疋 'Because the translation stage (4) vibration (50_) ^ if οα secret combination automatically scales to the scale element (8) (4), because the amplitude of the vibration is greater than the coherence length of the source, combined The CT system of the moving focus unit (8) has excellent consistency on the measured object (41) data, even if the accuracy of the poor translation stage (4) is selected and the translation stage (4) is vibrated. The experimental standard error of refractive index and thickness is still about 0·024 and 〇·243_, respectively. This proves that the combination of the autofocus device (8) in the OCT system can effectively reduce the error caused by external vibration. h, the optical receiver converts the interfering optical signal into an electrical signal: the first optical receiver (51) of the optical receiver (5) obtains the third beam (13) and the fourth beam (14) Interfering signals, and detecting interfering signals of the second beam (12) and the fourth beam (14), and the second photoreceiver (52) is for obtaining the second beam (12) and the third speed of light (14) Interfering signal, and an interference signal for detecting the second beam (12) and the third beam (13), and then converting the optical signal through the first and second light receivers (51), (52) For the telecommunication number. i. The processor analyzes the electrical signal: and then analyzes the electrical signals converted by the first and second optical receivers (51) and (52) via the processor (61). j. The display unit displays the image of the object to be measured and related information. Finally, the image of the object to be tested (41) and related information are obtained on the display unit (62). BRIEF DESCRIPTION OF THE DRAWINGS 1279606 The first drawing is a schematic view of a device embodying the present invention. The second figure is a schematic diagram of the astigmatism method of the embodiment of the present invention. The second figure is a flow chart of the steps of the method for implementing the present invention. The fourth figure is a schematic diagram of the measured object and the reference plane of the present invention. The fifth figure is the first and second light receiver receiving ports of the present invention. A schematic diagram of the signal. The sixth figure is an indication of the signal received by the first and second optical receivers at the Xs of the present invention.
圖。 第七圖係為本發明X。及Xs處訊號經第二道光束校正後之示 思圖。 ^圖係為本發明解調變訊號之示意圖。 圖係為本發明待測平移台於震動時誤差百分比曲線示 意圖。 第 圖係為本發明第一光接受器於接收校正後之解調變訊 ^不意圖。 〜圖係為本發明第二光接受器於接收校正後之解調變 ^ 訊號示意圖。 〜圖係為習知oct裝置之示意圖。 第+ - 二圖係為解調變技術之流程示意圖。 第十 四圖係為訊號調變之變化幅曲線示意圖。 t要元件符號說明】 (1) 光源 （11) 第一道光束 第二道光束 （13) 第三四道光束 19 1279606Figure. The seventh figure is the invention X. And the signal after the Xs signal is corrected by the second beam. The figure is a schematic diagram of the demodulation signal of the present invention. The figure is a graphical representation of the error percentage curve of the translation stage to be tested in the invention. The figure is a demodulation and transduction of the first optical receiver of the present invention after receiving the correction. The figure is a schematic diagram of the demodulation signal of the second optical receiver after receiving the correction. The figure is a schematic diagram of a conventional oct device. The first + - second diagram is a schematic flow chart of the demodulation technology. The fourteenth figure is a schematic diagram of the change curve of the signal modulation. t element symbol description] (1) light source (11) first beam second beam (13) third four beams 19 1279606
(14) 第四道光束 (15) 參考點 (2) 光纖1馬合器 (21) 第一光纖耦合器 (22) 第二光纖搞合器 (3) 掃描平移台 (31) 反射鏡 (4) 待測平移台 (41) 待測物體 (5) 光接受器 (51) 第一光接受器 (52) 第二光接受器 (6) 處理器 ⑺ 顯示單元 (8) 自動對焦單元 (81) DVD光學讀取頭 (82) 物鏡 (83) 致動器 (84) 圓柱透鏡 (85) 光碟片 (86) 透孔 (87) 光束準直器 (9) 控制單元 (A) 光源 (Al) 第一道光束 (A2) 第二道光束 (A3) 第三道光束 (B) 光纖輛合器 (C) 掃描平移台 (C1) 反射鏡 (D) 待測平移台 (D1) 待測物體 (E) 光接受器 (F) 處理器 (G) 顯示單元 (H) 控制單元 20(14) Fourth beam (15) Reference point (2) Fiber 1 horse coupler (21) First fiber coupler (22) Second fiber coupler (3) Scanning translation stage (31) Mirror (4 ) Translation stage to be tested (41) Object to be tested (5) Light receiver (51) First light receiver (52) Second light receiver (6) Processor (7) Display unit (8) Autofocus unit (81) DVD optical pickup (82) objective (83) actuator (84) cylindrical lens (85) optical disc (86) through hole (87) beam collimator (9) control unit (A) light source (Al) One beam (A2) Second beam (A3) Third beam (B) Fiber clutch (C) Scanning translation stage (C1) Mirror (D) Translation stage to be tested (D1) Object to be tested (E ) Light Receiver (F) Processor (G) Display Unit (H) Control Unit 20