200924329 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種Q-切換雷射，尤指一種提高増益 纖和飽和吸收光纖的核心直徑（核心面積）比值之+^ Γ “ 織型 被動式Q-切換雷射。 【先前技術】 所謂Q-切換雷射即是高功率脈衝雷射，而q_切換 產生高功率脈衝光的技術。Q-切換的技術又分主動式、是 動式。被動式Q_切換技術是使用一可飽和吸收的材^和被 置於雷射共振腔内’雷射一經激發即可自動產生高功放 衝光，因此被動式Q-切換雷射又稱飽和吸收Q-切j奐帝^脈 相較於主動式Q-切換雷射，飽和吸收Q-切換雷射=二 單、體積小、成本低。缺點是飽和吸收Q-切換的材料籌簡 取得。 、料不易 由於光纖的諸多優點，光纖型雷射是一新興熱門 究主題。目前市面上最常見的Q-切換光纖雷射，大多數研 是採用光纖外部Q-切換裝置’即雷射光需要先離開^纖仍 經過主動或被動Q-切換處理之後’再將光耦合進入光纖。 由於一般單模光纖的核心只有約10 μιη，不易輕合，如此 的操作會造成能量損失高、Q_切換效率低、光學封裳不易 和成本高等缺點。目前已發表並經實驗證實的主動式切 換全光纖雷射是藉由電光特性或聲光特性達到切換作用= 主動式Q-切換全光纖雷射，顧名思義是需要外部的電子驅 動設備，外加於光纖某區段上，用以改變其光學特2 ° 5 200924329 些驅動設備必須是可快速切換電性，一般來說是相當昂貴 且笨重。另外，在一些已發表的全光纖被動式Q-切換雷射 的相關文獻中，多是假設使用一些過渡金屬掺雜的特殊光 纖當作飽和吸收Q-切換，再經由模擬驗證雷射脈衝的產 生，事實上這些過渡金屬掺雜的特殊光纖是很難以製作並 且取得的。 美國公告第5652756號及美國公開第20060007965號 之技術内容皆非全光纖型之結構，光必須先離開光纖，處 理後再耦合回去光纖；而美國公告第7130319號之主要技 術雖是全光纖型，但必須使用主動式Q切換元件。 故習知Q-切換光纖雷射技術仍存有許多缺失，而有待 改進，且發明一全光纖型被動式Q-切換雷射，實為刻不容 緩之課題。 【發明内容】 本發明之目的在於提供一種全光纖型被動式Q-切換雷 射，使容易產生全光纖型飽和吸收Q-切換脈衝雷射，利用 此雷射架構提高原光纖型飽和吸收Q-切換脈衝雷射的Q-切換效率，產生更高功率的脈衝光；其原理是藉由提高增 益光纖和飽和吸收光纖的核心直徑（核心面積）比值，以降低 兩者核心的光強度密度比值，因而達到強化Q切換速率之 目的，且本發明結構簡單和成本低，可被廣泛應用在醫療、 醫學研究、物理基礎研究和工業精密加工上，而具有極大 的學術和商業價值，。 本發明之另一目的在於提供一種飽和吸收光纖，該飽 200924329 和吸收光纖可以吸收雷射波長，並且到達飽和後即不再吸 收，而該飽和吸收光纖的核心直徑（或面積）比增益光纖的核 心直徑（或面積）小’使得該飽和吸收光纖内的光強度密度大 於增益光纖内的光強度密度，因此可加速飽和吸收光纖達 到飽和狀態，進而產生Q_切換雷射脈衝。200924329 IX. Description of the invention: [Technical field of the invention] The present invention relates to a Q-switched laser, in particular to a ratio of the core diameter (core area) of a 増 纤 fiber and a saturated absorbing fiber. Q-switching laser. [Prior Art] The so-called Q-switched laser is a high-power pulsed laser, and the q-switching technology produces high-power pulsed light. The Q-switching technology is divided into active and active. Passive Q_switching technology uses a saturable absorption material and is placed in the laser cavity. 'A laser can automatically generate high power amplifier after excitation. Therefore, the passive Q-switched laser is also called saturated absorption Q-. Compared with the active Q-switched laser, the saturated absorption Q-switched laser = two single, small volume, low cost. The disadvantage is that the material of the saturated absorption Q-switching is simplified. Due to the many advantages of optical fiber, fiber-optic laser is a new topic of research. Currently, the most common Q-switched fiber laser on the market, most of which are fiber-optic external Q-switching devices, that is, laser light needs to leave the fiber first. Still passing After the dynamic or passive Q-switching process, the light is coupled into the fiber. Since the core of the single-mode fiber is only about 10 μm, it is not easy to lightly match. Such operation will result in high energy loss, low Q_switching efficiency, and optical sealing. Disadvantages and high cost, etc. The currently published and experimentally proven active switching all-fiber lasers achieve switching by electro-optic or acousto-optic characteristics = active Q-switched all-fiber lasers, as the name implies, require external electronics The drive device is applied to a section of the fiber to change its optical characteristics. 2 2009 5329 Some drive devices must be able to switch quickly, which is generally quite expensive and cumbersome. In addition, in some published all-fiber In the related literatures of passive Q-switched lasers, it is assumed that special transition fibers doped with transition metals are used as saturated absorption Q-switching, and then the generation of laser pulses is verified by simulation. In fact, the special characteristics of these transition metals are doped. Optical fiber is difficult to manufacture and obtain. The technical contents of US Bulletin No. 5652756 and US Public Publication No. 20060007965 are not all-optical. In the structure of the fiber type, the light must first leave the fiber, and then be coupled back to the fiber after processing; while the main technology of the US Bulletin No. 7130319 is an all-fiber type, but an active Q switching element must be used. There are still many defects in the shooting technology, and there is a need to improve, and the invention of an all-fiber passive Q-switching laser is an urgent task. [Invention] The object of the present invention is to provide an all-fiber passive Q-switching mine. Shooting, making it easy to produce all-fiber type saturated absorption Q-switched pulsed laser, using this laser architecture to improve the Q-switching efficiency of the original fiber-type saturated absorption Q-switched pulsed laser, resulting in higher power pulsed light; The ratio of the core diameter (core area) of the gain fiber and the saturated absorption fiber is increased to reduce the ratio of the light intensity density of the cores, thereby achieving the purpose of enhancing the Q switching rate, and the invention is simple in structure and low in cost, and can be Widely used in medical, medical research, physical basic research and industrial precision processing, it has great academic and commercial value. Another object of the present invention is to provide a saturated absorption fiber which can absorb the laser wavelength and no longer absorbs after reaching saturation, and the core diameter (or area) of the saturated absorption fiber is higher than that of the gain fiber. The core diameter (or area) is small such that the intensity of the light intensity in the saturated absorption fiber is greater than the intensity of the light intensity in the gain fiber, thereby accelerating the saturated absorption fiber to a saturated state, thereby generating a Q_switching laser pulse.
本發明之又一目的在於提供一種全光纖型共振腔（An all-fiber resonator) ’該全光纖型共振腔包含光纖和光纖型元 件，而該全光纖型共振腔可為駐波共振腔型式 (standing-wave resonators)，或為環型共振腔型式（ring resonators)，該兩種共振腔體内的結構設計必須避免飽和吸 收光纖吸收激發光源。 其中，飽和吸收Q-切換的材料原必需滿足一個先決條 件’即疋飽和吸收材料的absorpti〇n cross sectj〇n, σ▲必 需大於雷射增益材質的 stimulatedemissi〇ncr〇sssecti〇n, & 而且兩者比值愈大，飽和吸收Q_切換的效率愈 好二本發明即是藉由提高增益光纖内核心面積 '和飽和吸 收光纖内核心面積的比值，調整此—先決條件為：Another object of the present invention is to provide an all-fiber resonator (the all-fiber type resonator) comprising an optical fiber and a fiber-optic type resonator, and the all-fiber type resonant cavity can be a standing wave resonator type ( Standing-wave resonators), or ring resonators, must be designed in such a resonant cavity to avoid absorption of the excitation source by the saturated absorption fiber. Among them, the saturated absorption Q-switched material must have met a prerequisite 'absorpti〇n cross sectj〇n, σ ▲ must be greater than the lightning gain material of the stimulusemissi〇ncr〇sssecti〇n, & The greater the ratio of the two, the better the efficiency of the saturated absorption Q_switching. The present invention is adjusted by increasing the ratio of the core area in the gain fiber to the core area in the saturated absorption fiber. The prerequisites are:
由於雷射光被侷限在光纖内的光纖核心 藉由提高兮可降低光束在增益光纖(核：c ) ί*二;低々可提高光束在飽和吸收光纖 ί 因此可加速飽和吸收光纖達到飽和狀 ^ ^ Q•切換雷射脈衝。所以（―）、若飽和吸收材 枓的〇^、於雷射增益材㈣〜，本發明可藉由提高增益光 7 200924329 纖内核心面積j和飽和吸收光纖内核心面積j 、g α的比值， 使此材料可Q_切換雷射。因此，本發明使得鉋和吸收 換材料的選擇性大幅增加。（二）、若飽和吸收材料的^^切 大於雷射增益材質的，本發明可藉由提高4和 值，使得Q-切換效率大幅提升，產生更高功率的脈衝光 射。 為達到上述目的之全光纖型被動式Q-切換雷射，包含 一經由一激發光源放射出的激發光波；一第一光纖光栅， 設於該激發光源之輸出側；一增益光纖，設於該第一光纖 光柵之輸出侧；一飽和吸收光纖，設於該增益光纖之輸出 侧；以及一第二光纖光柵，設於該飽和吸收光纖之輸出側； 其中該飽和吸收光纖之核心面積或直徑比該增益光纖之核 心面積或直徑小，使得經過該飽和吸收光纖核心的光強度 密度大於經過該增益光纖核心的光強度密度。 該飽和吸收光纖的材質可吸收該雷射波長。 該飽和吸收光纖為掺铒光纖或其他等效之光纖。 該增益光纖為掺铒光纖或其他等效之光纖。 該第一光纖光柵可全反射雷射波長，而該第二光纖光 柵則提供一定比例反射雷射波長，剩餘比例則為雷射輸出。 【實施方式】 雖然本發明將參閱含有本發明較佳實施例之所附圖式 予以充分描述，但在此描述之前應瞭解熟悉本行之人士可 修改本文中所描述之發明’同時獲致本發明之功效。因此， 須暸解以下之描述對熟悉本行技藝之人士而言為一廣泛之 8 200924329 揭示，且其内容不在於限制本發明。 請參閱第-圖’賴示本發明全光纖型被動式Q _切換 雷射1弟一實她例之、、’σ構示意圖。本發明第一實施例之全 光纖型被動式Q-切換雷射1包含—經由一激發光源2放射 出的激發光波；一第一光纖光柵3，設於該激發光源2之輸 出侧；一增益光纖4 ’設於該第一光纖光栅3之輸出侧；一 飽和吸收光纖5 ’設於该增益光纖4之輸出側；以及一第二 光纖光栅6，設於該飽和吸收光纖5之輸出侧。 其中，當激發光波2教發該增益光纖4時會產生一自 體輻射光波和一雷射增益，經該第一光纖光柵3可全反射 該雷射光波之波長至該第二光纖光柵6’而於該第一光纖光 柵3與該第二光纖光桃6間共振。該共振的雷射光波經該 第二光纖光柵6 一部分輸出’ 一部份反射繼續共振。雷射 光波的形成是從自體輕射光波的放大開始。該自體辕射光 波經過該增益光纖4會被放大’而經過飽和吸收光纖5會 因被吸收而變小’使得自體輕射光波一開始被抑制而無法 被放大成雷射。但當飽和吸收光纖5到達吸收飽和狀態後 即不再吸收’此時自體輻射光波會在來回共振中被增益光 纖4快速放大’而形成一雷射脈衝。該飽和吸收光纖5之 核心面積或直徑比該增益光纖4之核心面積或直徑小，使 得經過該飽和吸收光纖5核心的光強度密度大於經過該增 益光纖4核心的光強度密度。如此結構設計可使飽和吸收 光纖5快速刻達吸收飽和狀態，進而產生Q-切換雷射脈衝。 而第一圖是最簡單的全光纖型被動式Q-切換雷射1， 為駐波共振腔結構’其中該飽和吸收光纖5的材質不會吸 200924329 收該激發光源2，該第一光纖光栅3是駐波共振腔的反射 鏡，可以全反射該雷射光波之波長，而該第二光纖光栅6 則提供一定比例的該雷射光波之波長反射，而剩餘比例為 雷射輸出7。 請參閱第二圖，係顯示本發明全光纖型被動式Q-切換 雷射11第二實施例之結構示意圖。本發明第二實施例之全 光纖型被動式Q-切換雷射11包含一經由一激發光源12放 射出的激發光波；一分波多工器13，設於該激發光源12之 輸出側；一飽和吸收光纖18，設於該分波多工器13之第一 側19; 一增益光纖14,設於該分波多工器13之第二侧15 ; 一第一光纖光栅16，設於該增益光纖14之第一側17 ;以 及一第二光纖光柵20，設於該飽和吸收光纖18之輸出側。 其中，該分波多工器13先導入該激發光源12所發射 之激發光波，且激發增益光纖14並避免該激發光源12被 該飽和吸收光纖18吸收。該增益光纖14接收來自於該分 波多工器13之激發光源會產生一自體輻射光波和一雷射增 益，並由該第一光纖光柵16全反射來自於該增益光纖14 之雷射光波之波長，而於該第一光纖光柵16與該第二光纖 光柵20間共振。該共振的雷射光波經該第二光纖光栅20 一部分輸出，一部份反射繼續共振。雷射光波的形成是從 自體輻射光波的放大開始。該自體輻射光波經過該增益光 纖14會被放大，而經過飽和吸收光纖18會因被吸收而變 小，使得自體韓射光波一開始被抑制而無法被放大成雷 射。但當飽和吸收光纖18到達吸收飽和狀態後即不再吸 收，此時自體輻射光波會在來回共振中被增益光纖14快速 200924329 放大，而成為一雷射脈衝。該飽和吸收光纖18之核心面積 或直徑比該增益光纖14之核心面積或直徑小，使得經過該 飽和吸收光纖18核心的光強度密度大於經過該增益光纖14 核心的光強度密度。如此結構設計可使飽和吸收光纖18快 速到達吸收飽和狀態，進而產生Q-切換雷射脈衝。 第二圖是第一圖的變型化，本發明第一實施例及第二 實施例同為駐波共振腔結構。其中該飽和吸收光纖18的材 質可以吸收該激發光源12。而該第一光纖光柵16是駐波共 振腔的反射鏡，可以全反射該雷射光波之波長，而該第二 光纖光柵20則提供一定比例的該雷射光波之波長反射，而 剩餘比例為雷射輸出21。 第三圖為本發明全光纖型被動式Q -切換雷射31之第三 實施例之結構示意圖。本發明第三實施例之全光纖型被動 式Q-切換雷射31包含一經由激發光源32發射出的激發光 波；一分波多工器33，係導入激發光波，且激發該增益光 纖38 ; —飽和吸收光纖34，設於該分波多工器33之第一 側35 ; —光循環器36，設置於該飽和吸收光纖34的輸出 側；一光纖光柵37，設置於該光循環器36之輸出側；一增 益光纖38，設於該分波多工器33之第二侧39，並介於該 分波多工器33及光循環器36之間。 其中，該分波多工器33先導入該激發光源32所發射 之激發光波，且激發該增益光纖38，該增益光纖38接收來 自於該分波多工器33之激發光源產生一自體輻射光波和一 雷射增益。該自體輻射光波經過該增益光纖38會被放大， 而經過分波多工器33到達飽和吸收光纖34會因被吸收而 11 200924329 變小。經該飽和吸收光纖34吸收後穿透的光波至該光循環 益36，而該光波先從該光循環器36之端點a至端點b再到 該光纖光柵37，該光纖光柵37可配合該光循環器36將光 波反射回去（從該光循環器3 6之端點b至端點c)而使該光波 經過該增益光纖38被放大，再依序循環共振。當飽和吸收 光纖34到達吸收飽和狀態時後即不再吸收，此時自體輻射 光波會在共振中被增益光纖38快速放大，而成為一雷射脈 衝。 由於該光循環器36本身可排除該激發光源32之雷射 光波之波長，因此不需考慮該飽和吸收光纖34可否吸收了 該激發光源32的雷射波長。該光循環器36配合該光纖光 栅37使得光波在環型共振腔只能有單一行進共振方向。而 該光纖光柵37把一定比例的雷射光波反射回去環型共振腔 内，而剩餘比例為雷射輸出40。該飽和吸收光纖34之核心 面積或直徑比該增益光纖3 8之核心面積或直徑小，使得經 過該飽和吸收光纖34核心的光強度密度大於經過該增益光 纖38核心的光強度密度。如此結構設計可使飽和吸收光纖 34快速到達吸收飽和狀態，進而產生（^切換雷射脈衝。 第四圖為本發明全光纖型被動式q_切換雷射41之第四 實施例之結構示意圖。本發明第四實施例之全光纖型被動 式Q-切換雷射41包含一經由一激發光源42放射出的激發 光波；一分波多工器43，係導入激發光波，且激發增益光 纖48 ; —光循環器44 ’設置於該分波多工器43的第一側 45 ; —飽和吸收光纖46，設於該光循環器44之輸出侧；一 光纖光柵47 ’設置於該飽和吸收光纖46之輸出侧；以及一 12 200924329 48:设於該分波多工器43之第二側49，並介於 5亥刀波夕工器43及光循環器44之間。 夕21'、*④分波多工器43先導人該激發光源42所發射 7 且激發該增益光纖48，該增益光纖48接收來Since the laser light is confined to the fiber core in the fiber, the beam can be reduced in the gain fiber (core: c) by increasing the chirp; the low beam can increase the beam in the saturated absorption fiber, thereby accelerating the saturation absorption fiber to reach saturation ^ ^ Q•Switch the laser pulse. Therefore, (―), if the saturated absorbing material 〇, and the laser gain material (4) 〜, the present invention can improve the ratio of the core area j of the gain light 7 200924329 and the core area j and g α of the saturated absorption fiber. , so that this material can Q_switch the laser. Therefore, the present invention greatly increases the selectivity of the planing and absorbing materials. (2) If the saturation absorption material is larger than the laser gain material, the present invention can increase the Q-switching efficiency by increasing the 4 and the value, thereby generating higher power pulsed light. The all-fiber passive Q-switching laser for achieving the above purpose comprises: an excitation light wave emitted by an excitation light source; a first fiber grating disposed on an output side of the excitation light source; and a gain fiber disposed at the first An output side of a fiber grating; a saturated absorption fiber disposed on an output side of the gain fiber; and a second fiber grating disposed on an output side of the saturated absorption fiber; wherein a core area or a diameter ratio of the saturated absorption fiber The core area or diameter of the gain fiber is small such that the intensity of the light intensity through the core of the saturated absorption fiber is greater than the intensity of the light intensity through the core of the fiber. The material of the saturated absorption fiber absorbs the laser wavelength. The saturated absorption fiber is an erbium doped fiber or other equivalent fiber. The gain fiber is an erbium doped fiber or other equivalent fiber. The first fiber grating can totally reflect the laser wavelength, while the second fiber grating provides a certain proportion of the reflected laser wavelength, and the remaining ratio is the laser output. The present invention will be fully described with reference to the accompanying drawings in which the preferred embodiments of the present invention are described, but it should be understood that those skilled in the art can modify the invention described herein while obtaining the invention. The effect. Therefore, it is to be understood that the following description is a broad disclosure of the disclosure of the present disclosure, and is not intended to limit the invention. Please refer to the figure-picture showing the all-fiber type passive Q _ switching laser of the present invention. The all-fiber passive Q-switching laser 1 of the first embodiment of the present invention comprises: an excitation light wave emitted through an excitation light source 2; a first fiber grating 3 disposed on an output side of the excitation light source 2; a gain fiber 4' is disposed on the output side of the first fiber grating 3; a saturated absorption fiber 5' is disposed on the output side of the gain fiber 4; and a second fiber grating 6 is disposed on the output side of the saturated absorption fiber 5. Wherein, when the excitation light wave 2 teaches the gain fiber 4, an auto-radiation light wave and a laser gain are generated, and the wavelength of the laser light wave can be totally reflected by the first fiber grating 3 to the second fiber grating 6' The first fiber grating 3 and the second fiber light peach 6 resonate. The resonant laser light propagates through a portion of the output of the second fiber grating 6 to continue to resonate. The formation of laser light waves begins with the amplification of self-lighting light waves. The self-excited light beam is amplified by the gain fiber 4 and becomes smaller by being absorbed by the saturated absorption fiber 5, so that the self-lighted light wave is initially suppressed and cannot be amplified into a laser. However, when the saturated absorption fiber 5 reaches the absorption saturation state, it is no longer absorbed. At this time, the self-radiation light wave is rapidly amplified by the gain fiber 4 in the back and forth resonance to form a laser pulse. The core area or diameter of the saturated absorption fiber 5 is smaller than the core area or diameter of the gain fiber 4, so that the light intensity density passing through the core of the saturated absorption fiber 5 is greater than the light intensity density passing through the core of the gain fiber 4. Such a structural design enables the saturated absorption fiber 5 to be rapidly ingested to absorb the saturation state, thereby generating a Q-switched laser pulse. The first figure is the simplest all-fiber passive Q-switched laser 1 , which is a standing wave resonant cavity structure. The material of the saturated absorption fiber 5 does not absorb the excitation light source 2, and the first fiber grating 3 It is a mirror of the standing wave resonator, which can totally reflect the wavelength of the laser light wave, and the second fiber grating 6 provides a certain proportion of the wavelength reflection of the laser light wave, and the remaining ratio is the laser output 7. Referring to the second figure, there is shown a schematic structural view of a second embodiment of the all-fiber type passive Q-switching laser 11 of the present invention. The all-fiber passive Q-switching laser 11 of the second embodiment of the present invention comprises an excitation light wave emitted through an excitation light source 12; a wavelength division multiplexer 13 is disposed on the output side of the excitation light source 12; An optical fiber 18 is disposed on the first side 19 of the split multiplexer 13; a gain fiber 14 is disposed on the second side 15 of the split multiplexer 13; a first fiber grating 16 is disposed on the gain fiber 14 The first side 17; and a second fiber grating 20 are disposed on the output side of the saturated absorption fiber 18. The splitter multiplexer 13 first introduces the excitation light wave emitted by the excitation light source 12, and excites the gain fiber 14 and prevents the excitation light source 12 from being absorbed by the saturated absorption fiber 18. The gain fiber 14 receives an excitation light source from the split multiplexer 13 to generate an autoradiation light wave and a laser gain, and the first fiber grating 16 totally reflects the laser light from the gain fiber 14. The wavelength resonates between the first fiber grating 16 and the second fiber grating 20. The resonant laser light is output through a portion of the second fiber grating 20, and a portion of the reflection continues to resonate. The formation of a laser light wave begins with the amplification of the self-radiating light wave. The self-radiating light wave is amplified by the gain fiber 14, and becomes smaller by being absorbed by the saturated absorption fiber 18, so that the autogenous Korean light wave is initially suppressed and cannot be amplified into a laser. However, when the saturated absorption fiber 18 reaches the absorption saturation state, it is no longer absorbed. At this time, the self-radiation light wave is amplified by the gain fiber 14 in the back and forth resonance, and becomes a laser pulse. The core area or diameter of the saturable absorbing fiber 18 is smaller than the core area or diameter of the gain fiber 14 such that the intensity of the light intensity through the core of the saturated absorbing fiber 18 is greater than the intensity of the light passing through the core of the gain fiber 14. Such a structural design allows the saturated absorption fiber 18 to quickly reach the absorption saturation state, thereby generating a Q-switched laser pulse. The second figure is a modification of the first figure, and the first embodiment and the second embodiment of the present invention are the same as the standing wave resonator structure. The material of the saturated absorption fiber 18 can absorb the excitation light source 12. The first fiber grating 16 is a mirror of the standing wave resonant cavity, which can totally reflect the wavelength of the laser light wave, and the second fiber grating 20 provides a certain proportion of the wavelength reflection of the laser light wave, and the remaining ratio is Laser output 21. The third figure is a schematic structural view of a third embodiment of the all-fiber passive Q-switching laser 31 of the present invention. The all-fiber passive Q-switching laser 31 of the third embodiment of the present invention comprises an excitation light wave emitted by the excitation light source 32; a wavelength division multiplexer 33 is introduced to the excitation light wave and excites the gain fiber 38; The absorption fiber 34 is disposed on the first side 35 of the split multiplexer 33; the optical circulator 36 is disposed on the output side of the saturated absorption fiber 34; and a fiber grating 37 is disposed on the output side of the optical circulator 36. A gain fiber 38 is disposed on the second side 39 of the split multiplexer 33 and interposed between the split multiplexer 33 and the optical circulator 36. The splitter multiplexer 33 first introduces the excitation light wave emitted by the excitation light source 32, and excites the gain fiber 38. The gain fiber 38 receives an excitation light source from the splitter multiplexer 33 to generate an autoradiation light wave. A laser gain. The self-radiating light wave is amplified by the gain fiber 38, and is passed through the splitter multiplexer 33 to reach the saturated absorption fiber 34, which is reduced by the absorption 11 200924329. The light wave that is transmitted after being absorbed by the saturated absorption fiber 34 reaches the light cycle benefit 36, and the light wave first passes from the end point a to the end point b of the optical circulator 36 to the fiber grating 37, and the fiber grating 37 can be matched. The optical circulator 36 reflects the light waves back (from the end b of the optical circulator 36 to the end point c) such that the light is amplified by the gain fiber 38 and sequentially circulates. When the saturated absorption fiber 34 reaches the absorption saturation state, it is no longer absorbed, and at this time, the self-radiation light wave is rapidly amplified by the gain fiber 38 in resonance to become a laser pulse. Since the optical circulator 36 itself can exclude the wavelength of the laser light of the excitation light source 32, it is not necessary to consider whether the saturated absorption fiber 34 can absorb the laser wavelength of the excitation light source 32. The optical circulator 36 cooperates with the fiber grating 37 so that the light wave can only have a single traveling resonance direction in the ring type resonant cavity. The fiber grating 37 reflects a certain proportion of the laser light back into the toroidal resonant cavity, and the remaining ratio is the laser output 40. The core area or diameter of the saturated absorption fiber 34 is smaller than the core area or diameter of the gain fiber 38 such that the intensity of the light intensity passing through the core of the saturated absorption fiber 34 is greater than the intensity of the light passing through the core of the gain fiber 38. Such a structural design enables the saturated absorption fiber 34 to quickly reach the absorption saturation state, thereby generating (^ switching the laser pulse. The fourth figure is a schematic structural view of the fourth embodiment of the all-fiber passive q_switching laser 41 of the present invention. The all-fiber passive Q-switching laser 41 of the fourth embodiment of the invention comprises an excitation light wave emitted through an excitation light source 42; a wavelength division multiplexer 43 is introduced to the excitation light wave, and the excitation gain fiber 48; The device 44' is disposed on the first side 45 of the splitter multiplexer 43; a saturated absorption fiber 46 is disposed on the output side of the optical circulator 44; and a fiber grating 47' is disposed on the output side of the saturated absorption fiber 46; And a 12 200924329 48: disposed on the second side 49 of the split multiplexer 43 and between the 5th knives and the optical circulator 43. The eve 21', *4 splitter multiplexer 43 The pilot activates the light source 42 to emit 7 and excites the gain fiber 48, which is received by the gain fiber 48.
自於Μ波多工器43之激發㈣產生—自體騎光波和一 雷射增益。該自體_光波經過該增益級48會被放大。 光波經過，分波多工3 43至該光循環器44。先從該光循環 器44之端點a至端點b，並且經過該飽和吸收光纖46而到 該光纖光棚47 ’該光纖光栅47可配合該光循環器44將雷 射光波反射回去’再經過該飽和吸收光纖46。光波兩次經 過该飽和吸收光纖46會因被吸收而變小。光波(從該光循環 器44之端點b至端點c)，到達該增益光纖48被放大，再 依序循環共振。當飽和吸收光纖34到達吸收飽和狀態時後 即不再吸收’此時自體輻射光波會在共振中被增益光纖38 快速放大’而成為一雷射脈衝。 第四圖是第三圖的改良型，本發明第三實施例及第四 實施例同為環型共振腔結構。由於該光循環器44本身可排 除該激發光源42之雷射波長，因此不需考慮該飽和吸收光 纖40可否吸收了該激發光源42的雷射波長。該光循環器 4 4配合該光纖光柵4 7使得光波在環型共振腔只能有單一行 進共振方向。而該光纖光柵47把一定比例的雷射光波反射 回去環型共振腔内’而剩餘比例為雷射輸出5〇。該飽和吸 收光纖46之核心面積或直徑比該增益光纖48之核心面積 或直徑小’使得經過該飽和吸收光纖46核心的光強度密度 大於經過該增益光纖48核心的光強度密度。如此結構設計 13 200924329 决速到達吸收飽和狀態，進而產生q_ 請參閱第五圖，係顯示本發明全光 雷射11第二實施例之數據圖，並配 &被動式Q-切換 14和該飽和吸收光纖18為同樣口^。該增盈光纖 Π = ti18核心面積比值為8’共振腔週 ，月長度為1 Λ尺。該飽和吸收光纖18的小訊號 (small-signal loss)取為3dB，兮第一氺继丄上 °儿、 .^ , A 7 ϋ茲弟先纖光柵16和該第二 先，光柵20之反射頻譜的中心波長$ 155〇·、頻寬為 〇.8nm、中心波長的反射率各為1〇〇%和7〇%。該分波多工 ，13可以把980mn波長的激發光源12耦合進入共振腔並 ;文么該增ϋ光纖14。模擬結果顯示此雷射設計可產生連續 脈衝，脈衝之間隔約為13ms。每一個脈 6 心脈衝寬度25.5nS。^假設輸出模態直===，則功 率密度可達約145MW/cm2。The excitation from the chopper multiplexer 43 (4) produces - self-propelled light waves and a laser gain. The auto-light wave will be amplified by the gain stage 48. The light wave passes through, and the multiplexer 3 43 is split to the optical circulator 44. From the end point a to the end point b of the optical circulator 44, and through the saturated absorption fiber 46 to the fiber optic shed 47', the fiber grating 47 can cooperate with the optical circulator 44 to reflect the laser light back. The saturated absorption fiber 46 passes through. The light wave twice passes through the saturated absorption fiber 46 and becomes smaller as it is absorbed. The light wave (from the end b of the optical circulator 44 to the end point c) reaches the gain fiber 48 and is amplified, and then sequentially resonates. When the saturated absorption fiber 34 reaches the absorption saturation state, it is no longer absorbed. At this time, the self-radiation light wave is rapidly amplified by the gain fiber 38 in resonance to become a laser pulse. The fourth figure is a modified version of the third figure, and the third embodiment and the fourth embodiment of the present invention are both ring-shaped resonator structures. Since the optical circulator 44 itself can exclude the laser wavelength of the excitation source 42, it is not necessary to consider whether the saturated absorption fiber 40 can absorb the laser wavelength of the excitation source 42. The optical circulator 4 cooperates with the fiber grating 47 so that the light wave can only have a single direction of resonance in the ring-shaped resonant cavity. The fiber grating 47 reflects a certain proportion of the laser light wave back into the ring-shaped resonator cavity' while the remaining ratio is 5 雷 of the laser output. The saturated absorption fiber 46 has a core area or diameter that is smaller than the core area or diameter of the gain fiber 48 so that the intensity of the light intensity through the core of the saturated absorption fiber 46 is greater than the intensity of the light intensity through the core of the gain fiber 48. Thus, the structural design 13 200924329 reaches the absorption saturation state, and then generates q_. Referring to the fifth figure, the data diagram of the second embodiment of the plenoptic laser 11 of the present invention is shown, and the & passive Q-switch 14 and the saturation are shown. The absorption fiber 18 is the same port. The gain fiber Π = ti18 core area ratio is 8' resonator cavity circumference, and the length of the month is 1 Λ. The small-signal loss of the saturated absorption fiber 18 is taken as 3 dB, and the first 氺 丄 、 、 . . . . A A A A A A A A A A A 和 和 和 和 和 和 和 和 和 和 和 和 和The center wavelength of the spectrum is $155 〇·, the bandwidth is 〇.8 nm, and the reflectance at the center wavelength is 1% and 7%, respectively. The split multiplexer 13 can couple the excitation source 12 of 980 nm wavelength into the resonant cavity; The simulation results show that this laser design produces continuous pulses with a pulse interval of approximately 13 ms. Each pulse 6 heart pulse width is 25.5nS. ^ Assuming the output mode is straight ===, the power density can reach about 145 MW/cm2.
可使飽和吸收光纖34 切換雷射脈衝。 请參閱下列表一，係顯示本發明全光纖型被動式〇_切 換雷射1、11、31、41等四個實施例所產生的脈衝輸出，而 全光纖型被動式Q-切換雷射1、11、31、41均使用相同的 模擬假設如下：增益光纖和飽和吸收光纖的核心面積比值 為8 ’比值(σ/σα)為卜共振腔週期長度為1公尺’ 飽和吸收光纖的小訊號損耗(small-signal loss)為3dB。輸出 端的光纖光柵中心波長為1550nm、中心波長的反射率為 70%。非飽和吸收性損耗為〇.5dB。 200924329 表一 雷射架構圖 式 酿衝間隔 (ms) 脈衝能量 m 脈衝寬度 (ns) 脈衝最大功 率(Watt) 脈衝最大功率雅 度(MW/cm2) 第一圖 13 11.6 25.5 457 145 第二圖 13 11.6 25.5 457 145 第三圖 19 13 44 l3〇5 97 第四圖 ~~ -- 11 24 22.5 1063 338 / :在本發明第四實施例全光纖型被動式Q_切換雷射中， 該，和吸收光纖係置於該光纖光栅之前，可使得該飽和吸 纖内有—上—下來回的光傳遞方向，藉此增加該飽和 ^先纖㈣光強度密度，因而更強化了㈣換效率。本 收激^ ^，腔體内的結構設計原則是避免飽和吸收光纖吸 本發明之優點在於：The saturated absorption fiber 34 can be switched to a laser pulse. Please refer to Table 1 below for the pulse output generated by the four embodiments of the all-fiber passive 〇_switching lasers 1, 11, 31, 41, etc. of the present invention, and the all-fiber passive Q-switching lasers 1, 11 31, 41 use the same simulation hypothesis as follows: the core area ratio of the gain fiber and the saturated absorption fiber is 8 ' ratio (σ / σα) is the length of the cavity period of 1 m'. The small signal loss of the saturated absorption fiber ( Small-signal loss) is 3 dB. The center of the fiber grating at the output is 1550 nm and the reflectance at the center wavelength is 70%. The unsaturated absorption loss is 〇5 dB. 200924329 Table 1 Laser architecture pattern brewing interval (ms) Pulse energy m Pulse width (ns) Pulse maximum power (Watt) Pulse maximum power elegance (MW/cm2) First Figure 13 11.6 25.5 457 145 Second Figure 13 11.6 25.5 457 145 Third Figure 19 13 44 l3〇5 97 Fourth Figure ~~ -- 11 24 22.5 1063 338 / : In the all-fiber passive Q_switching laser of the fourth embodiment of the present invention, the absorption and absorption Before the fiber is placed in the fiber grating, the saturated fiber can have a light-transmitting direction of up-down and back-and-forth, thereby increasing the light intensity density of the saturated fiber (4), thereby further enhancing the (four) switching efficiency. The principle of structural design in the cavity is to avoid saturation absorption of the fiber. The advantages of the invention are:
L光纖輕便易操作。 2. 能量損失低。 3. Q-切換效率高。 4·封骏容易。 5.製作成本低。 限定發”佳實施翻露如上1其並非用以 和範圍内一悉此技#者’在不脫離本發明之精神 護範圍，〜=各ί之更動與潤飾，因此，本發明之保 田視後附之申請專利範圍所界定者為準。 15 200924329 【圖式簡單說明】 第一圖為本發明全光纖型被動式Q-切換雷射之第一 實施例之結構不意圖。 第二圖為本發明全光纖型被動式Q-切換雷射之第二 實施例之結構不意圖。 第三圖為本發明全光纖型被動式Q-切換雷射之第三 實施例之結構不意圖。 第四圖為本發明全光纖型被動式Q-切換雷射之第四 實施例之結構示意圖。 第五圖為本發明全光纖型被動式Q-切換雷射第二實 施例之數據圖。 【主要元件符號說明】 1、 11、31、41…全光纖型被動式Q-切換雷射 2、 12、32、42…激發光源 3、 16 —第一光纖光拇 4、 14、38、48…增益光纖 5、 18、34、46—飽和吸收光纖 6、 20…第二光纖光柵 7、 21、40、50…雷射輸出 13…分波多工器 15、39、49---第二側 17、19、35、45…第一側 33、43…分波多工器 36、44…光循環器 16 200924329 37、47…光纖光柵L fiber is light and easy to operate. 2. Low energy loss. 3. Q-switching efficiency is high. 4. Sealing is easy. 5. The production cost is low. The limited implementation of the preferred embodiment is as disclosed above, and it is not intended to be within the scope of the invention. Without departing from the scope of the present invention, the modification and retouching of the ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ ̄ The scope of the patent application is subject to change. 15 200924329 [Simple description of the drawings] The first figure is not intended to be the structure of the first embodiment of the all-fiber passive Q-switched laser of the present invention. The structure of the second embodiment of the all-fiber passive Q-switched laser is not intended. The third figure is a schematic diagram of the structure of the third embodiment of the all-fiber passive Q-switched laser of the present invention. A schematic diagram of a fourth embodiment of an all-fiber passive Q-switched laser. The fifth figure is a data diagram of a second embodiment of an all-fiber passive Q-switched laser of the present invention. [Description of main components] 1.11 , 31, 41... all-fiber passive Q-switched laser 2, 12, 32, 42... excitation light source 3, 16 - first fiber optical thumb 4, 14, 38, 48... gain fiber 5, 18, 34, 46 - Saturated absorption fiber 6, 20... second fiber grating 7 , 21, 40, 50... laser output 13... splitter multiplexer 15, 39, 49---second side 17, 19, 35, 45... first side 33, 43... splitter multiplexer 36, 44... Optical circulator 16 200924329 37, 47... fiber grating
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