1261123 九、發明說明： 【發明所屬之技術領域】 本發明係有關一種可調式長週期光纖光柵結構及製造 方法，係藉由溫度之調整，材料間熱膨脹係數的不匹配使 光纖產生預期之微彎曲變形，形成一類似傳統光栅發生模 態耦合的現象，進而達到以溫控來調變濾波頻譜的功效之 結構及製造方法。 【先前技術】 長週期光纖光栅在光通訊市場上為一重要的元件，其 在商業應用上主要是以光罩法（Phase Mask Method)在 光纖上寫製成光栅。可作為帶拒濾、波器（Band Rejection Filter)、模態轉換器（Mode Converters)、增益平坦化 濾波器（Gain Equalizers)等多種應用。優點為全光纖 元件’其與光纖連結時之損失小、低插入損失（Insertion Loss)、低背向反射（Back Reflection)等，對於高溫、 彎曲、扭轉以及負載具高度敏感性，因此適合光通訊及感 測器之發展。但經由光罩法製造出來的長週期光纖光柵其 特性隨著製程條件不一致而需要準確的控制，且一旦寫入 光纖即無法回復與調整。 鑒於以上之優缺點，故外力式、可調式、簡單構造的 長週期光纖光柵逐漸為發展的重點：以下說明兩種長週 期光纖光柵濾波器美國專利。 美國第6, 282, 341 B1號專利揭示一種機械可調式的長 1261123 週期光纖光栅濾波器，此一濾波器包含一對週期性的機械 結構（亦可為一週期結構加上一平板），將光纖箝制其中 ，上下週期結構突起和突起處對齊咬合，直接施加壓力於 光纖表面，因此在光纖上藉由光彈效應造成直接的折射率 擾動，形成一光柵；藉由調整施於週期結構上的壓力，控 制折射率的擾動量，可以調變頻譜深度（損失）；另外藉 由週期結構形狀與排列的設計，可以改變波長與頻譜形狀 ，以及消除極化相關損失（Polarization Dependence Loss)。本項專利的精神著重在壓力擠迫光纖導致之光彈效 應所造成的折射率擾動，而要避免微彎曲的產生；此外光 纖必須加以保護（jacketed)，不然效率會較差且有額外的 損失（1-2dB)。 美國第6,408，117 81號專利同樣揭示一種機械可調式 長週期光纖光栅，不同於上篇專利，其僅具有單邊週期結 構，另一邊則是附帶有彈性材料的平板，將光纖鉗制於兩 者之間，以多隻螺絲加以固定並藉此調整鬆緊；彈性材料 的目的在於當雙邊咬合時，對光纖施與一均佈力使其在週 期結構的支撐下形成連續微彎曲的型態，而產生光柵的效 果；藉由調整螺絲的鬆緊、彈性材料的選擇、週期結構的 設計、排列、變化，達到頻譜調整的目的。本項專利的精 神著重在微彎曲的產生所形成的光栅效應，但同樣的此光 纖必須加以保護（包覆上低折射率塑膠），否則強度、可靠 度及頻譜的深度（損失）都不理想。 1261123 【發明内容】 ^本發明之主要目的，乃在於提供—射調 纖光栅結構，以溫度控制解決習〜、週期光 力使光纖產生連續微f曲< nT + _機械式的外 損的問題。 應能造成光纖受 本發明之次要目的，乃在於提供 纖光栅結構製造方法，以—種簡 ==光 件組合，取代習知技術中多數的 ^ ^數的元 需的繁複步驟，節省成本。 ㈣成後雜的結構所 本發明之-種可調式長週期光纖_ =’其上具週期狀結構，具有-第-熱膨服係 H，係蚊-光纖於該週期狀結構，具有 脹糸數；其中’該第-熱膨脹係數與該第二熱膨脹係數俜 不相同，在溫度變化下，兩材料，即基材與接合劑之敎膨 脹係數不-致造成光纖呈現微彎曲之現象，形成—光拇的 效果。 【實施方式】 請參閱圖一所示，係本發明可調式長週期光纖光栅結 構示意圖。本發明係包括：一基材1〇〇，其上具週期狀結構 150，具有一第一熱膨脹係數；一接合劑2⑽，係令一無披 覆層且之單模光纖3〇〇整條分布固定於該週期狀結構丨5〇 上，具有一第二熱膨脹係數；一熱電致冷晶片121，以提供 本發明可調式長週期光纖光柵結構溫度變化用，更有其他 1261123 板:加熱線’同樣可以達成溫控的目的;其中， ^ ^ _數與該第二熱膨脹係數係不相同，在溫度 變化下，兩材料，Pd # 上1 L 口 卩基材與接合劑之熱膨脹係數不一致造 成光纖呈現微彎曲之相名 ^ ^ ^ ^ ^現象，形成一類似光柵的效果，調變 >皿度及纟又計週期έ 士娱 構即可改變其穿透頻譜之波形，如深度 八^辰；1二。以上所述之基材可為下列任一種材料所製成： 金屬、半導體、祜殖以 敬’材料、陶瓷材料、複合材料和塑膠。 而该接合制可為下列彳 ^ 咬* 幻任—種：咼溫固化、常溫固化。 ^ W ^閱圖五所示’係本發明之週期狀結構立體圖式。 係使用、泉切副的加工方式在鋼材上切出V形的溝槽⑸，其 週期寬度為650微半 ^ 木’味度約為284微米，角度為90度，下 方之圓角為線切副之線經造成（直徑微米）。咖微米 之為了滿足相位關係式在153()及1585奈米附近 之〃振;皮長其相位關係式與長週期光纖光柵之基本特性 將如下說明： 光波彳于經長週期光纖光栅後會產生繞射現象，將正向 傳播的基本纖核模態（Core Mode) _合至正向傳播的纖 设拉悲（Cladding Mode)，其負一階繞射光將滿足相位關 係式（Phase Match Condition):1261123 IX. Description of the invention: [Technical field of the invention] The present invention relates to an adjustable long-period fiber grating structure and a manufacturing method thereof. The temperature is adjusted, and the thermal expansion coefficient between materials does not match, so that the optical fiber produces the desired microbend. The deformation forms a phenomenon similar to the phenomenon that the conventional grating is modally coupled, thereby achieving the effect of modulating the filtering spectrum by temperature control. [Prior Art] Long-period fiber gratings are an important component in the optical communication market, and in commercial applications, gratings are mainly written on optical fibers by the Phase Mask Method. It can be used as a band rejection filter, Band Rejection Filter, Mode Converters, Gain Equalizers and many other applications. The advantage is that the all-fiber component has small loss, low insertion loss, low back reflection, etc., and is highly sensitive to high temperature, bending, torsion and load, so it is suitable for optical communication. And the development of sensors. However, the characteristics of long-period fiber gratings manufactured by the photomask method require precise control as process conditions are inconsistent, and cannot be restored and adjusted once written into the fiber. In view of the above advantages and disadvantages, long-period fiber gratings with external force, adjustable and simple construction are gradually becoming the focus of development: the following two US patents for long-period fiber grating filters are described. US Patent No. 6,282,341 B1 discloses a mechanically adjustable long 1261123 period fiber grating filter comprising a pair of periodic mechanical structures (also a periodic structure plus a flat plate) In the fiber clamp, the protrusions and protrusions of the upper and lower periodic structures are aligned and directly applied to the surface of the optical fiber, so that a direct refractive index disturbance is caused by the photoelastic effect on the optical fiber to form a grating; by adjusting the structure applied to the periodic structure Pressure, controlling the amount of disturbance of the refractive index, can modulate the depth (loss) of the spectrum; in addition, by the shape and arrangement of the periodic structure, the wavelength and spectral shape can be changed, and the polarization dependent loss (Polarization Dependence Loss) can be eliminated. The spirit of this patent focuses on refractive index perturbations caused by photoelastic effects caused by pressure-extrusion fibers, while avoiding the occurrence of microbending; in addition, the fibers must be jacketed, otherwise the efficiency will be poor and there will be additional losses ( 1-2dB). US Patent No. 6,408,117 81 also discloses a mechanically adjustable long-period fiber grating, which differs from the previous patent in that it has only a single-sided periodic structure, and the other side is a flat plate with an elastic material, and the optical fiber is clamped to both. Between the two, the screws are fixed and the elastic is adjusted; the purpose of the elastic material is to apply a uniform force to the optical fiber to form a continuous micro-bend under the support of the periodic structure when the two sides are engaged. The effect of the grating is achieved; the purpose of spectrum adjustment is achieved by adjusting the tightness of the screw, the selection of the elastic material, the design, arrangement and variation of the periodic structure. The spirit of this patent focuses on the grating effect created by the microbending, but the same fiber must be protected (coated with low refractive index plastic), otherwise the strength, reliability and depth (loss) of the spectrum are not ideal. . 1261123 [Draft] The main purpose of the present invention is to provide a radiation-modulating grating structure, with temperature control to solve the ~, periodic light force to produce a continuous micro-f song of the optical fiber < nT + _ mechanical external damage problem. It should be able to cause the optical fiber to be the secondary purpose of the present invention, and to provide a method for manufacturing a fiber grating structure, and to replace the complicated steps required by most of the conventional techniques in the prior art, and to save costs. . (4) Structure after the formation of the invention - The adjustable long-period fiber _ = ' has a periodic structure, has a - first thermal expansion system H, a mosquito-fiber in the periodic structure, with expansion Where the 'the first thermal expansion coefficient is different from the second thermal expansion coefficient ,, under the temperature change, the two materials, that is, the expansion coefficient of the substrate and the bonding agent are not-induced, causing the fiber to exhibit micro-bending phenomenon, forming - The effect of light thumb. [Embodiment] Please refer to FIG. 1 , which is a schematic diagram of the structure of the adjustable long period fiber grating of the present invention. The present invention comprises: a substrate 1 having a periodic structure 150 having a first coefficient of thermal expansion; and a bonding agent 2 (10) for uncoated layer and a single mode fiber 3 Fixed on the periodic structure 丨5〇, having a second coefficient of thermal expansion; a thermoelectrically cooled wafer 121 for providing temperature change of the adjustable long-period fiber grating structure of the present invention, and more other 1261123 boards: heating line 'the same The purpose of temperature control can be achieved; wherein ^ ^ _ number is different from the second coefficient of thermal expansion, and under temperature change, the thermal expansion coefficients of the material and the bonding agent of the two materials, Pd #1, Pd # and the bonding agent are inconsistent, resulting in fiber presentation The micro-bending phase name ^ ^ ^ ^ ^ phenomenon, forming a grating-like effect, modulation > degree and 纟 cycle counts can change the waveform of the penetration spectrum, such as depth 八辰; 1 two. The substrates described above can be made of any of the following materials: metals, semiconductors, ceramics, ceramics, composites, and plastics. The bonding system can be the following 咬 ^ bite * illusion - type: 咼 warm curing, room temperature curing. ^ W ^See Figure 5 is a perspective view of the periodic structure of the present invention. The V-shaped groove (5) is cut out on the steel by the processing method of the spring cutting pair, and the period width is 650 micro-half. The wood taste is about 284 micrometers, the angle is 90 degrees, and the rounded corners are line cuts. The secondary line is created (diameter in diameter). In order to satisfy the phase relationship between 153() and 1585 nm, the basic characteristics of the skin length and the long-period fiber grating are as follows: The light wave will be generated after the long-period fiber grating The diffraction phenomenon, the forward propagation of the basic core mode (Core Mode) _ to the forward propagation of the Cladding Mode, the negative first-order diffracted light will satisfy the Phase Match Condition (Phase Match Condition) :
LWH(A)二 2WA A為真空中的波長，/)_，/&·為基本纖核與第n階纖殼模態的 傳播常數，λ為週期間距；在纖核中傳播的基模波長若滿 足相位匹配關係式（共振波長），則會被導引至纖殼内，造 成纖核中光的能量損失，形成損失峰，此特性即為濾波的 1261123 基礎。 加工完成之基材100,其上具有經過設計之週期狀纟士構 150，然而，在基材1〇〇上的週期狀結構15〇、接合劑2⑽與 單模光纖300彼此互相結合的方式具有以下二實施例，即接 合劑填滿於週期狀結構方式與接合劑填充於部份週期狀、社 構上方式，將逐一說明。 如圖二A與圖二B所示，係本發明之第一較佳實施例， 即接合劑填滿於週期狀結構方式。圖二，接合劑2〇〇填 滿於溝槽151中’㈣光纖·垂直於週期結構15();放其、 上，由於接合劑200之黏性與毛細5見象，光纖3〇〇會自動與 週期結構完整_合，固化後之結構在溫度降低時，因著 接合劑2GG所具有的第二熱膨關數與基材⑽所具有的第 :熱膨脹係數不同，於是，接合劑2〇〇往下之收縮力，如箭 碩Y ’與基材1QG之水平收縮力，如箭頭狀以，同時促進 了微彎曲之形成；另-方面，在溫度昇高時，本實施例會 ，向使得光纖彎曲減小。目二B所示，係本實施例加裳^ 、欠條溫控線路111。如圖中所示，該溫控線路U1可固定於 2期狀結構15G的溝槽151中，同時可作為光纖綱之支點與 =度調整用’以達到對接合獅Q與基材丨㈣直接的溫度 ^制。本次實施例，即接合劑填滿於週期狀結構方式，係 可利用苐二熱賴係數大於第—熱祕餘的界定達成較 好的結果。 如圖二A與圖二B所示，係本發明之第二較佳實施例， 即接合劑填充於部份週期狀結構上方式。圖三人中，接合劑 1261123 200塗佈於週期狀結構150’之頂端，該頂端可為尖形、圓 弧形或其他形狀，亦可均勻地塗佈於週期狀結構的^緣，' 但溝槽151並不填滿，僅在與光纖3〇〇’接觸的端點作纟士入 ◦固化後之結構於溫度降低時，以基材丨〇〇,之水平收縮力， 如箭頭ΧΓ與X2，，為主之效應及接合劑2〇〇,於端點旁之收 縮力，如箭頭ΧΥΓ與XY2，，促進了微彎曲之形成；在溫产 昇高時，本實施例反向使得光纖彎曲減小。圖三，係2 實施例加裝複數條溫控線路m，。該溫控線路m，於本實 施例的結構中係對應著每一個接合劑2〇〇,與溝槽l5i，接觸 _ 的端點，以對於接合劑2〇〇,直接調整其溫度。 如圖四所示，係本發明之詳細基材立體圖式，且本圖 式的元件編號係沿用圖三、圖二A與圖二B，該不鏽鋼基材 、 100包括週期狀結構15〇的溝槽151與一導引槽131，該導引 ' 槽131為一淺半圓（半徑10〇微米），目的在於使光纖3〇〇黏著 於週期結構150表面時保持與溝槽151垂直，以固定間距 ;亦可以刻意導引使光纖與週期結構呈現特定夾角或彎曲 ，達到特殊的間距變化。 ® 根據上述實例而使用不同種類之接合劑硬化，可得到 不同之頻譜特性，茲詳述於下： 若採用加熱固化的接合劑，即高溫固化接合劑，如EPO--TEn53^D-T ’其須在15(rc下加熱固化—小時，此時光纖 Ϊ!!溫Ϊ保持平直的，固化完成後隨著物體的逐漸冷卻至 f溫、，藉由前述的熱膨脹係數不匹配產生之應力，我們可 知到、漸钇強的彎曲效應；實驗結果如圖六所示，係本發 10 1261123 明採用加熱固化的接合劑之頻譜圖◦圖中，在趨近150°C時 之高溫濾波頻譜呈現平坦，但隨著溫度逐漸降低，兩個共 振波峰逐漸明顯，以30個週期長度之週期狀結構而言，當 達到室溫25°C時，其第二共振模態損失峰達到-16dB ◦ 若採用室溫固化的接合劑，即常溫固化接合劑，如 Chemi tech U-425，其必須在紫外線光源下曝照數分鐘才會 硬化，此時光纖在常溫是保持平直的，固化完成後降低物 體的溫度，藉由前述的熱膨脹係數不匹配產生之應力，可 得到逐漸增強的彎曲效應；實驗結果如圖七所示，係本發 明採用室溫固化的接合劑之頻譜圖。在常溫之濾波頻譜呈 現平坦，但隨著溫度逐漸降低至-15°C時，以28個週期長度 之週期狀結構而言，其第二共振模態損失峰達到-14dB。 由上述兩種不同種類的接合劑所作的實驗，可得以下 兩種結論· 1. 具有高溫固化接合劑的濾波器，加熱使其濾波效率逐漸 降低，因此在室溫具有濾波效果，但高溫波形呈現平坦 ，如圖六所示； 2. 具有常溫固化接合劑的濾波器，降溫使其濾波效率增強 ，因此在室溫具有平坦波形，低溫才具濾波效果，如圖 七戶斤示； 因此，可藉由溫度的調整來對這兩者做預期的控制。 以上所述共有兩方面可調整濾波效果，即改變接合劑 在週期狀結構上的塗佈方法與使用不同種類的接合劑。於 是，在這兩方面交互配合應用，可發展出複數種可行的組 1261123 合模式，以符合各種不同的情形。 如圖八所示，係本發明之接合劑、週期狀結構與光纖 三種接合態樣示意圖。圖中，左邊圖式係顯示接合劑200 之塗佈高度剛好及於光纖300的下邊，亦即與週期狀結構 150同高；中間圖式則是接合劑200之塗佈高度剛好及於光 纖300的1/2;右邊圖式則顯示接合劑200之塗佈淹漫過光纖 300。因著接合劑塗布之厚度及與光纖的接著面積大小可改 變光纖之週期性彎曲程度，而適當的厚度（約達1/2光纖高 度）可提供最佳的彎曲（bending)效率。 · 如圖九所示，係本發明之接合劑、週期狀結構與光纖 最佳配合態樣位移示意圖。圖中，被接合劑所填滿之週期 狀結構，其結構輪廓外形可經最佳化設計，使得光纖每一 週期性彎曲與接合劑之收縮路徑一致，以利接合劑與光纖 介面之應力達到最小。 如圖十所示，係本發明之合併外力控制基材示意圖。 圖中，複數個外力，箭頭Fb F2、ΤΙ、T2、T3、T4，係分 鲁 別作用於基材100上，以進行濾波效果的改變。因此，本發 明除了可以溫度控制為主外，亦可再以外力輔助控制。 請參考圖十一所示，係本發明之一種可調式長週期光 — 纖光柵結構的製作方法，其步驟包括： - (1) 準備一具有週期狀結構的基材，如金屬、半導體、玻璃 材料、陶瓷材料、複合材料或塑膠之材料製成，該基材 具有一第一熱膨脹係數； (2) 準備一接合劑，如高溫固化或常溫固化接合劑，該接合 12 1261123 劑具有一第二熱膨脹係數； (3)2接合劑填充於該週期狀結構，如一般週期狀結構或漸 文，期狀結構，係可以機械加工、半導體製程、金屬或 塑膠射出成型、壓模成型與沖模製成，· (4) 將一整條無披覆層單模光纖分布於週期狀結構上； (5) 利用接合劑將光纖緊固於週期結構上； (6) 結束。 其中’該第二熱膨脹係數不同於第一熱膨脹係數，在 溫度變化下，兩材料，即基材與接合劑之熱膨脹係數不一 致造成光纖呈現微彎曲之現象’形成一類似光栅的效果， =變溫度及設計結構即可改變其穿透頻譜之波形，如 /朱度、共振波長。 如前所述’週期狀結構分為一 期狀結構，因此，請參考圖十變週 明-般週期狀結構實施例二係分聯 實施例示意圖°其中，該—般狀、纟喻為下 如，十二A所示之悝定間距尖齒狀結構、如圖十二 :疋間距此一構、如圖十二c所示之恆定 構；該漸變週期狀結構可為下列任—種：如圖十^ ^ f間距尖齒狀結構、如圖十三B所示之漸變間二： 構、如圖十三C所示之漸變間距混合結構、如圖 之漸變間距波浪狀結構。同時，週期狀結構俜可；有= 之週期數量’以配合所需之頻譜寬度與深度:…、有不同 如上所述，本發明係利用 又 』用不同物質的膨脹係數不同， 13 1261123 而以溫度控制或外力控制，達到一種可調式長週期光纖光 柵結構。其中，無論從結構成本、技術精神，皆以異於習 知技㈣角m不值節省成本、技術原理簡單易懂， 更可針對不_條件進行不同的搭配，以達廣泛運用的成 效：更有甚者，其連續性的串接不同之基材（週期結構）， 穿透頻譜具加成的效果，以達到㈣（Shaping)、增益平 坦（Gainequalizer)的目的，且因為全光纖元件，適合 光通訊及❹m業之魏，可作為帶拒濾波器 (BandLWH(A) 2WAA is the wavelength in vacuum, /)_, /& is the propagation constant of the basic fibrin and the nth-order fiber-shell mode, λ is the periodic spacing; the base propagating in the nucleus If the mode wavelength satisfies the phase matching relationship (resonance wavelength), it will be guided into the shell, causing the energy loss of light in the core to form a loss peak. This characteristic is the basis of the filtered 1261123. The processed substrate 100 has a designed periodic gentleman structure 150 thereon. However, the periodic structure 15 在 on the substrate 1 , the bonding agent 2 ( 10 ) and the single mode fiber 300 are combined with each other. The following two embodiments, that is, the manner in which the bonding agent is filled in the periodic structure and the bonding agent are filled in a part of the periodic state or the structure, will be explained one by one. As shown in Fig. 2A and Fig. 2B, the first preferred embodiment of the present invention, that is, the bonding agent is filled in a periodic structure. 2, the bonding agent 2〇〇 fills the trench 151 '(4) fiber · perpendicular to the periodic structure 15 (); put it on, because the adhesion of the bonding agent 200 and the capillary 5, the fiber 3 The automatic and periodic structure are completely integrated. When the temperature is lowered, the second thermal expansion coefficient of the bonding agent 2GG is different from the first thermal expansion coefficient of the substrate (10), so that the bonding agent 2〇 The downward contraction force, such as the horizontal contraction force of the arrow Y' and the substrate 1QG, as the arrow shape, promotes the formation of microbends; on the other hand, when the temperature rises, the embodiment will make Fiber bending is reduced. As shown in FIG. 2B, in this embodiment, the skirting temperature control circuit 111 is added. As shown in the figure, the temperature control line U1 can be fixed in the groove 151 of the 2-stage structure 15G, and can be used as the fulcrum of the fiber-optic frame and the degree adjustment is used to achieve direct connection to the lion Q and the substrate 四 (4). The temperature is ^. In this embodiment, the bonding agent is filled in the periodic structure, and the better result can be achieved by using the definition of the second thermal coefficient greater than the first heat secret. As shown in Fig. 2A and Fig. 2B, a second preferred embodiment of the present invention is a manner in which the bonding agent is filled in a portion of the periodic structure. In the three figures, the bonding agent 1261123 200 is applied to the top end of the periodic structure 150'. The top end may be pointed, circular arc or other shape, and may be evenly applied to the edge of the periodic structure, 'but The groove 151 is not filled, and only after the temperature at which the temperature is lowered at the end of the contact with the optical fiber 3', the horizontal contraction force of the substrate is as shown by the arrow ΧΓ. X2, the main effect and the bonding agent 2〇〇, the contraction force beside the end point, such as the arrow ΧΥΓ and XY2, promote the formation of microbending; in the case of an increase in temperature production, the present embodiment reverses the fiber The bending is reduced. Figure 3, the embodiment 2 is installed with a plurality of temperature control lines m. The temperature control line m, in the structure of the present embodiment, corresponds to each of the bonding agents 2, and contacts the end of the groove ln5, to directly adjust the temperature of the bonding agent 2 。. As shown in FIG. 4, it is a detailed perspective view of the substrate of the present invention, and the component numbers of the figure are based on FIG. 3, FIG. 2A and FIG. 2B. The stainless steel substrate, 100 includes a groove having a periodic structure of 15 inches. The groove 151 and a guiding groove 131 are a shallow semicircle (radius 10 〇 micrometer), and the purpose is to keep the optical fiber 3 垂直 perpendicular to the groove 151 when the surface of the periodic structure 150 is adhered to the fixed spacing. It is also possible to deliberately guide the fiber to a specific angle or bend with the periodic structure to achieve a special pitch change. ® Different types of bonding agents can be obtained by hardening different types of bonding agents according to the above examples. Details are given below: If a heat-curing bonding agent is used, ie, a high-temperature curing bonding agent such as EPO--TEn53^DT' Heat curing at 15 (rc), at this time, the fiber is Ϊ!! The temperature is kept flat, and after the curing is completed, as the object gradually cools to f temperature, the stress caused by the thermal expansion coefficient mismatch does not occur. The experimental results are shown in Fig. 6. The spectrum of the high-temperature filter is flat at 150 °C. However, as the temperature gradually decreases, the two resonance peaks become more and more obvious. With a periodic structure of 30 cycles, when the temperature reaches 25 °C, the second resonance mode loss peak reaches -16 dB. A room temperature curing bonding agent, such as a room temperature curing bonding agent, such as Chemi tech U-425, which must be exposed to an ultraviolet light source for a few minutes to harden, at which point the fiber remains flat at room temperature and is reduced after curing. The temperature of the body can be gradually enhanced by the stress caused by the mismatch of the thermal expansion coefficients described above. The experimental results are shown in Fig. 7. The spectrum of the cement cured at room temperature is used in the present invention. The spectrum is flat, but as the temperature gradually decreases to -15 ° C, the second resonance mode loss peak reaches -14 dB in a periodic structure of 28 cycles. The above two different kinds of bonding agents The following experiments can be used to obtain the following two conclusions: 1. A filter with a high-temperature curing cement, heating to gradually reduce the filtering efficiency, so it has a filtering effect at room temperature, but the high-temperature waveform is flat, as shown in Figure 6; 2. The filter with room temperature curing bonding agent, the temperature drop makes the filtering efficiency increase, so it has a flat waveform at room temperature, and the low temperature has a filtering effect, as shown in Figure 7; therefore, the temperature can be adjusted by The above is the expected control. There are two aspects to adjust the filtering effect, that is, changing the coating method of the bonding agent on the periodic structure and using different kinds of connections. Therefore, in the two aspects of the interaction application, a plurality of feasible group 1261123 modes can be developed to meet various situations. As shown in FIG. 8, the bonding agent, the periodic structure and the optical fiber of the present invention are three. Schematic diagram of the joint pattern. In the figure, the left diagram shows that the coating height of the bonding agent 200 is just above the lower side of the optical fiber 300, that is, the same as the periodic structure 150; the middle drawing is the coating height of the bonding agent 200. Just 1/2 of the fiber 300; the right figure shows that the coating of the bonding agent 200 is flooded through the fiber 300. The periodic bending of the fiber can be changed due to the thickness of the bonding agent and the size of the bonding area of the fiber. A suitable thickness (approximately 1/2 fiber height) provides optimum bending efficiency. · As shown in FIG. 9 , it is a schematic diagram of the displacement of the bonding agent, the periodic structure and the optical fiber of the present invention. In the figure, the periodic structure filled with the bonding agent can be optimized in design, so that each periodic bending of the optical fiber is consistent with the shrinking path of the bonding agent, so that the stress between the bonding agent and the optical fiber interface is achieved. The smallest. As shown in FIG. 10, it is a schematic diagram of the combined external force control substrate of the present invention. In the figure, a plurality of external forces, arrows Fb F2, ΤΙ, T2, T3, and T4, are applied to the substrate 100 to perform a change in the filtering effect. Therefore, in addition to the temperature control, the present invention can also be assisted by external force. Referring to FIG. 11, a method for fabricating an adjustable long-period optical fiber grating structure according to the present invention comprises the steps of: - (1) preparing a substrate having a periodic structure such as a metal, a semiconductor, or a glass. Made of material, ceramic material, composite material or plastic material, the substrate has a first coefficient of thermal expansion; (2) preparing a bonding agent, such as a high temperature curing or room temperature curing bonding agent, the bonding 12 1261123 agent has a second Thermal expansion coefficient; (3) 2 bonding agent filled in the periodic structure, such as a general periodic structure or a gradual, periodical structure, can be mechanical processing, semiconductor processing, metal or plastic injection molding, compression molding and die making (4) Distribute an entire uncoated single-mode fiber to the periodic structure; (5) Fasten the fiber to the periodic structure with a bonding agent; (6) End. Wherein the second coefficient of thermal expansion is different from the first coefficient of thermal expansion. Under the temperature change, the two materials, that is, the thermal expansion coefficient of the substrate and the bonding agent are inconsistent, causing the fiber to exhibit a slight bending phenomenon to form a grating-like effect, = variable temperature And the design structure can change the waveform of its penetration spectrum, such as / Zhu Du, resonance wavelength. As mentioned above, the 'periodic structure is divided into a one-stage structure. Therefore, please refer to the figure of the tenth-period-like periodic structure. The second embodiment is a schematic diagram of the sub-connection example. Among them, the general shape and the analogy are as follows. For example, the fixed pitch pitched structure shown in FIG. 12A, as shown in FIG. 12: the pitch of the structure, as shown in FIG. 12c; the graded periodic structure may be any of the following: As shown in Fig. 10, the pitch is a dentate structure, as shown in Fig. 13B, the gradation is two: the structure, the gradation spacing hybrid structure as shown in Fig. 13C, and the gradation spacing wavy structure as shown in the figure. At the same time, the periodic structure can be; the number of cycles with = 'to match the required spectral width and depth: ..., different as described above, the present invention utilizes different coefficients of expansion of different substances, 13 1261123 Temperature control or external force control to achieve an adjustable long-period fiber grating structure. Among them, no matter from the structural cost and technical spirit, it is different from the conventional technology. (4) The angle m is not worth the cost, the technical principle is simple and easy to understand, and the different collocations can be made for different conditions to achieve the effect of wide application: In some cases, the continuity of the different substrates (periodic structure), the penetration spectrum has the effect of adding, in order to achieve (four) (Shaping), gain flatness (Gainequalizer) purposes, and because of all-fiber components, suitable Optical communication and ❹m industry Wei, can be used as a rejection filter (Band
Rejection Filter)、模態轉換器（M〇de c〇nverters)、 曰孤平:L·化;慮波斋Equalizers)及壓力、位移、 溫度感測器等多種應用。 本發明在新穎、性與進步性的探討如下：新穎性··丨.使 用一般早模光纖製造，不需蝕刻光纖纖殼（Cladding)，具 有傳$長週期光纖光柵之特性，同時又可對於濾波頻譜加 周正’ 2·利用材料熱膨脹係數的不匹配及結構的設計， 藉由/孤度、交化造成光纖的週期性微彎曲，達成濾波的效果 ，3:材料接合時硬化特性（高溫/常溫硬化）的選擇，可提供 性頟:卜的頻喑特性(咖脆…㈤/。⑴以資利用；進步 吏長週期光纖光柵具有可調性，同時改善了光纖直 又 罪度不佳的缺點。2·在小的溫度變化範圍内（攝 、、^使用35個週期，以一般的單模光纖便可達到-21dB 、勺濾波放卞。疋故，本發明已符合發明專利標的的新穎性、 ^二產業利用性，爰依法申請發明專利，並請鈞局 心予詳審賜予專利，實感德便。 14 1261123 【圖式簡單說明】 圖一係本發明可調式長週期光纖光柵結構示意圖； 圖二A與圖二B係本發明之第一較佳實施例； 圖三A與圖三B係本發明之第二較佳實施例； 圖四係本發明之詳細基材立體圖式； 圖五係本發明之週期狀結構立體圖式； 圖六係本發明採用加熱固化的接合劑之頻譜圖； 圖七係本發明採用室溫固化的接合劑之頻譜圖； 圖八係本發明之接合劑、週期狀結構與光纖三種接合態樣 不意圖， 圖九係本發明之接合劑、週期狀結構與光纖最佳配合態位 移不意圖， 圖十係本發明之合併外力控制基材示意圖； 圖十一係本發明之一種可調式長週期光纖光柵結構的製作 方法。 圖十二係本發明一般週期狀結構實施例示意圖； 圖十三係本發明漸變週期狀結構實施例示意圖。 【圖號簡單說明】 100基材 111溫控線路 121熱電致冷晶片 131導引槽 150週期狀結構 1261123 151溝槽 200接合劑 300光纖 100’基材 111’溫控線路 150’週期狀結構 15Γ溝槽 200’接合劑 300’光纖 XI箭頭 X2箭頭 Y箭頭 ΧΓ箭頭 X2’箭頭 ΧΥΓ箭頭 XY2’箭頭 F1箭頭 F2箭頭 T1箭頭 T2箭頭 T3箭頭 T4箭頭 1〜6係步驟編號Rejection Filter), modal converters (M〇de c〇nverters), 曰 平 :: L·化; 益波斋 Equalizers) and pressure, displacement, temperature sensors and other applications. The invention is novel, sexual and progressive as follows: novelty··. Uses general early-mode fiber manufacturing, does not need to etch fiber crust (Cladding), has the characteristics of transmitting long-period fiber grating, and at the same time The filtering spectrum plus Zhou Zheng' 2·Using the mismatch of the thermal expansion coefficient of the material and the design of the structure, the periodic micro-bending of the fiber is caused by / solitude and cross-linking to achieve the filtering effect, 3: the hardening property of the material bonding (high temperature / The choice of room temperature hardening can provide the characteristics of 頟: 的 喑 ( 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖 咖Disadvantages. 2. Within a small temperature variation range (photographing, using ^ 35 cycles, with a typical single-mode fiber can reach -21dB, scoop filtering and arranging. Therefore, the invention has met the novelty of the invention patent Sexuality, the use of the second industry, 申请 apply for invention patents according to law, and ask the squad to give a detailed examination and grant a patent. It is a real feeling. 14 1261123 [Simplified illustration] Figure 1 is an adjustable long-period fiber grating of the present invention. 2A and 2B are a first preferred embodiment of the present invention; FIG. 3A and FIG. 3B are a second preferred embodiment of the present invention; FIG. 4 is a detailed perspective view of the substrate of the present invention; Figure 5 is a perspective view of the periodic structure of the present invention; Figure 6 is a spectrogram of the cement cured by the present invention; Figure 7 is a spectrogram of the present invention using a room temperature curing cement; The bonding state, the periodic structure and the three kinds of bonding modes of the optical fiber are not intended. FIG. 9 is a schematic diagram of the bonding agent, the periodic structure and the optimal matching state of the optical fiber of the present invention, and FIG. 10 is a schematic diagram of the combined external force control substrate of the present invention; Figure 11 is a schematic diagram of a method for fabricating an adjustable long-period fiber grating structure according to the present invention. Figure 12 is a schematic view showing an embodiment of a general periodic structure of the present invention; Figure 13 is a schematic view showing an embodiment of a gradual periodic structure of the present invention. Brief description] 100 substrate 111 temperature control line 121 thermoelectric cooling wafer 131 guiding groove 150 periodic structure 1261123 151 groove 200 bonding agent 300 optical fiber 100' substrate 111' temperature control line 150' 15Γ trench structure 200 of 'bonding agent 300' arrow X2 fiber arrow Y arrow XI ΧΓ arrow X2 'ΧΥΓ arrow arrow XY2' arrow F1 arrow F2 arrow arrow T1 T2 T3 arrow arrow arrow T4 step numbers based 1~6