TW479135B - Waveguide fiber measurement apparatus - Google Patents

Abstract

Disclosed is an apparatus for measuring the properties of an optical waveguide fiber. The apparatus is free of apertures, lenses, and mirrors usually required in the measurement of certain waveguide fiber properties. The apparatus employs an optical switch at the launch end of the optical fiber to be tested and another optical switch at the output end of the optical fiber to be tested. The switches preserve the mode power distribution, particularly the spot size, of light passing therethrough. The apparatus maybe used to measure bandwidth or attenuation of a multimode wavelength fiber, both of which are affected by launched and detected mode power distribution.

Description

479135 A7 __；__ B7 五、發明説明（I ) ’ 發明領域： 本發明係關於一種量測波導纖維光學特性之、裝置特 別是關於使用光學切換光源或感測器之裝置。 |發明背景： 波導纖維光學量測為量測處理過程之昂貴部份。特別 是多模光纖量測情況，其包含頻寬，衰減，數值孔徑，心蕊直 彼，以及不同的模延遲。傳統上光學量測系統使用光學分 接頭以及整體光學組件，其包含透鏡以及可移動反射鏡以 曲折光學路徑以及合併不同的量測訊號。建立一項測試光 纖之連接為使用XYZ平移載台於感測器前之最終透鏡之前 面。平移載台在可移動零件中已知對溫度為靈敏性以及為 不％疋的。光纖之光線投射端部連接至適合所需要量測: 光源。 +由於特定多模光纖光學特性，即頻寬以及衰減為投射 重敏性的，通常使用多於一個所需要投射條件之量測。除 此，在大於一個波長下量測通常需要作許多次投射端部之 連接。 因而，這些量測分接頭非常緩慢，難以對準以及保持為 對準，以及其表面積大小約為數平方公尺大小。為了保持''' 重現性，該分接頭必需使用標準化光纖對標準分接頭週期 性地加以標定。其通常為耗時以及耗費之重複量測。 目M，多模光纖性能規範之標準光學規格包含量測點 大小以及數值孔徑之投射條件，其激發多模波導纖維所有 模。投射條件稱為過度填充條件以及在業界纖維光學洌試 尽技佐尺度適用中國囚家標準（CNS )八4規格（210X 297公發） (請先閱讀背面之注意事項再填寫本頁)479135 A7 __; __ B7 V. Description of the Invention (I) ′ Field of the Invention: The present invention relates to a device for measuring the optical characteristics of waveguide fibers, especially a device using optical switching light sources or sensors. Background of the Invention: Optical measurement of waveguide fibers is an expensive part of the measurement process. This is especially the case for multimode fiber measurement, which includes bandwidth, attenuation, numerical aperture, heart core, and different mode delays. Traditionally, optical measurement systems use optical taps and integral optical components, which include lenses and movable mirrors to meander optical paths and combine different measurement signals. To establish a test fiber connection, use an XYZ translation stage in front of the final lens in front of the sensor. Translation stages are known to be sensitive to temperature and not tolerable in moving parts. The light-projecting end of the fiber is connected to the appropriate measurement: the light source. + Because the optical characteristics of a specific multimode fiber, that is, the bandwidth and attenuation are projection-sensitive, usually more than one measurement of the required projection conditions is used. In addition, measurements at more than one wavelength often require many projection end connections. As a result, these measurement taps are very slow, difficult to align and remain aligned, and their surface area is about a few square meters. To maintain '' 'reproducibility, the tap must be calibrated periodically using standard fiber optics. It is usually a time-consuming and costly repeated measurement. Head M, the standard optical specifications for multimode fiber performance specifications include the measurement point size and the projection conditions of the numerical aperture, which excite all modes of the multimode waveguide fiber. The projection conditions are called overfilling conditions and fiber optic testing in the industry. The best standard is applicable to the Chinese Prisoner's Standard (CNS) 8-4 specification (210X 297). (Please read the precautions on the back before filling this page)

479135 A7479135 A7

翅wing

二 νψ t卜Two νψ t

處理過程(F0TP)54標準中加以界定。使用有效或限制投射 進行衣減测試，其稱為有限相位空間投射(LPS)以及在f〇tp 5〇中界定。LPS投射類似於3〇微米點大小投射，其將說明於 底下。 ' 目别，雷射光源最佳化多模光纖之需求已增加不同投 射條件數目之頻寬量測。因而增加量測分接頭處之連接數 目，该分接頭將使問題化。 因而需要纖維光學量測裝置，其提供使連接以及裝置 兀件與被測試光纖之對準變為容易。切換波導纖維投射端 部於不同波長光源間或投射條件應該為快速的以及重現性 的。 本發明符合符合價廉，快速的，以及更可靠性之波導纖 維量測。 發明大要： 本發明一項係關於量測光學波導纖維裝置，其在測試 日:在光纖投射端部處使用Νχ1光學切換器以及在測試時在 光纖感測為端部處使用1χΜ光學切換器。光源具有所需要 之波長以及投射條件，即點大小以及數值孔徑均連接至 切換器N個稱之—。制雜連接她丨城懸個端璋 之一。其結果為光纖能夠連接於兩個切換器之間以及在作 所有需要量測時保持為連接的。 投射端部切換選娜保持絲之投雜件，即模功率 分佈。感測器端部切換器選擇將保持在測試情況下離開光 纖之光線模功率分佈。對於歡制，—财考光纖首先 A7 A7 經^^!中央^^局員工消'->.:^;^^.!^-:1 連接於切換器之間以建立例如底線投射功率或投射脈沖寬 度。因而在頻寬量測時，在測試情況下通過光纖之脈沖寬 度與參考脈沖寬度作比較。對衰減量測作相同的比較，除 了在測試情況下離開光纖功率量測與投射功率作比較。 在本發明一項實施例中，投射光線之點大小或數值孔 牷隨著不同光源而變化。特定的一些光源為單模雷射。在 優先實施例中，單模雷射光源之點大小在8微米至3〇微米範 圍内。 在另外一個實施例中投射光線之點大小或數值孔徑可 加以限制使得並非多模光纖所有運載功率之模受到激勵。 一量測裝置之另外一個實施例包含一個〇TDR藉由1 χ2耦 ，器耦合至切換器使得光線之一些反射功率投射進入光纖 每一端部。OTDR連接詳細情況描述於圖1中。 本發明其他特性與優點將揭示於下列詳細說明中，熟· 知此技術者將由其中了解或藉由實施本發明之詳細說明， 申請專利範圍以及附圖所揭示而了解。 —人們了解先前之一般性說明以及下列詳細說明只作為 乾例性，以及在於提供一個概念或架構以了解本發明之原 理=及特性。附_為提供更進_步了解本發明，以及構 兄明書之-部份。關顯示出本發明實闕，以及隨同 說明作為解釋本發明之原理及操作。 附圖簡單說明： V第一圖（圖1)顯示出本發明波導纖維量測裝置之實施 例示意圖。 、Process (F0TP) 54 standard is defined. The subtraction test is performed using either effective or limited projections, which is called finite phase space projection (LPS) and is defined in f0tp 50. The LPS projection is similar to a 30 micron dot size projection, which will be explained below. 'For now, the need to optimize multimode fiber for laser light sources has increased the bandwidth measurement for the number of different projection conditions. Therefore increasing the number of connections at the measurement tap will make the problem worse. There is therefore a need for a fiber optic measurement device that provides ease of connection and alignment of the device element and the fiber under test. Switching the projection ends of waveguide fibers between different wavelength light sources or projection conditions should be fast and reproducible. The invention complies with inexpensive, fast, and more reliable waveguide fiber measurement. Important points of the invention: One aspect of the present invention relates to measuring optical waveguide fiber devices. On the test day: using the χ1 optical switch at the end of the fiber projection and using the 1 × M optical switch at the end of the fiber when testing . The light source has the required wavelength and projection conditions, that is, the point size and the numerical aperture are connected to the switch N, called —. The miscellaneous system connects her to one of the city's hanging ends. The result is that the fiber can be connected between the two switches and remain connected for all required measurements. The projection end is switched to select the miscellaneous pieces of the holding wire, that is, the mold power distribution. The sensor end switch selection will maintain the power distribution of the light mode of the fiber leaving the fiber under test. For the system, the financial test fiber first A7 A7 via the ^^! Central ^^ bureau staff to eliminate '->.:^; ^^.! ^-: 1 connected between the switches to establish, for example, the bottom line projection power or Projection pulse width. Therefore, in the bandwidth measurement, the pulse width passing through the fiber under the test condition is compared with the reference pulse width. The same comparison is made for the attenuation measurement, except that the power measurement leaving the fiber is compared with the projected power in the test case. In one embodiment of the present invention, the point size or numerical aperture 投射 of the projected light varies with different light sources. Certain light sources are single-mode lasers. In the preferred embodiment, the spot size of the single-mode laser light source is in the range of 8 microns to 30 microns. In another embodiment, the point size or numerical aperture of the projected light may be limited such that not all modes carrying power of the multimode fiber are excited. Another embodiment of a measurement device includes an OTDR via a 1x2 coupling coupled to a switch so that some reflected power of light is projected into each end of the fiber. The details of the OTDR connection are shown in Figure 1. Other features and advantages of the present invention will be disclosed in the following detailed description, and those skilled in the art will understand or understand by implementing the detailed description of the present invention, the scope of the patent application and the disclosure of the drawings. —People understand that the previous general description and the following detailed description are only examples, and are intended to provide a concept or framework to understand the principles and characteristics of the present invention. Attached to provide a further understanding of the present invention, and to form part of the brother's book. Guan shows the essence of the present invention, and the accompanying description serves to explain the principle and operation of the present invention. Brief description of the drawings: The first diagram (V) of V shows a schematic diagram of an embodiment of the waveguide fiber measuring device of the present invention. ,

(請先間讀背而之注意事項#填寫本K )(Please read the back first and note #Fill this K)

附圖元件數字符號說明： 辆4;光學時_域反射儀6;切換器8 式;、t ;連12;光源14;拼接18;可變衰減器2ι 志/貝'為22;切換器24;分析構件26;光纖尾辮28。 誶細說明： 圖中現在對本發明優先實施例詳細說明，其範例顯示於附 數字量測實施之範例性實施例顯示於圖1中，以及以 士本《明里測波導纖維之裳置包含Νχ1切換器2以在測古式 %投射光能進入光纖。圖i顯示每一光源4經由1χ2連接 12光學地連接嫌η讀謂固輸人端埠之_。在_情兄 ，第二光學連接經由切換器12連接至1χΜ切換器8輪出端部 。。亥排列允权們由峨賴每—卿制(_光點。在 切換器2之_輸人稱處觸*為光賴對光齡—種或 多種波長下測試時不同模色散(DMD)之量測。 么光纖可光學地藉由拼接18連接至量測裝置仞。這些連 接能夠藉由齡雜或業界已知的麵纖方^。可變化 衰減器2阿放置於線路中以使投射光線神對感二器 22為太㈣。當收集先前所提及參考光線訊號時有可能使 感測器過度感測。切換器24所在位置將使由感測器發出光 線功率使用於數據儲存以及分析構件26甲。通常分析以及 儲存構件包含示波器及計算機，其具有類比轉換為數位之 界面這些刀析構件為業界所熟知（參閱先前所提及pQTp)Description of the digital symbols of the drawing elements: car 4; optical time-domain reflectometer 6; switch 8 type ;, t; link 12; light source 14; splicing 18; variable attenuator 2 m / b '22; switch 24 Analysis member 26; fiber pigtail 28; Detailed description: The preferred embodiment of the present invention is now described in detail in the figure, an example of which is shown in FIG. 1 with a digital measurement implementation, and an example of the “Miritsu ’s waveguide fiber dress including N × 1 switching” The device 2 enters the optical fiber at a% of the projected light energy. Fig. I shows that each light source 4 is optically connected to the read end of a human input port via a 1x2 connection. At _love brother, the second optical connection is connected to the 1 × M switch 8-wheel output end via switch 12. . The arrangement of the right is made by Eilai-Qing (_light point. Touch at the _ input of switch 2 * is the amount of different mode dispersion (DMD) of the light ray vs. light age-test at one or more wavelengths. The optical fiber can be optically connected to the measuring device by splicing 18. These connections can be made by the age or surface fiber of the industry ^. A variable attenuator 2A can be placed in the line to make the projected light look good. The second sensor 22 is too sensitive. When collecting the previously mentioned reference light signals, the sensor may be over-sensed. The position of the switch 24 will allow the light power emitted by the sensor to be used for data storage and analysis components. 26A. Usually the analysis and storage components include oscilloscopes and computers, which have an analog to digital interface. These analysis components are well known in the industry (see pQTp mentioned earlier)

權响觸，舞此並不更 如下投射條件或模功率分狀範例說明 孔ί(Ν = 點大小約為9. 3微米以及數值 ：^=28物純2—-入料 在峨情況下藉由使賴準單模先纖與多模 先緘以及將姆於多模光纖之單絲纖《偏移而達成。 適度關之投射條件關使,峰多模光纖捲 %於心軸為光纖尾職而達成。該光、娜祕繞桃腿直徑 心軸以產生3G微米點大小以及數值孔徑為〇· 13。 過度填滿投射能夠使用階躍折射率多模光纖作為光纖 尾瓣而達成，其心蕊直徑大於⑽微歧數值孔徑大於〇· 3。 範例： 使用圖1裝置進行量測。切換器2為JDS，Dp8T切換器 PN: SC1618-D2SP SO6B0366。重複進行測試，切換器2分 別使用 JDS切換器，lx2切換器pn:sw12-Z000311 SN:JC0349 91，以及 1x8切換器PN:SB0108-Z000329 SN:GB029604。可 受衣減菇20為JDS，PN:HA9-Z046 SN:KC000660。使用四個 不同的投射條件以量測62. 5微米心蕊，125微米外徑光纖之 頻寬。其詳細說明說明如下： •標準過度填滿藉由TIA/EIA FOTP界定出； •適度限制投射條件提供30微米點，藉由使用5匝50微 米心蕊光纖捲繞於5麵直徑心軸而達成； 4、纸張尺度適用中國囡家標毕（CNS ) Λ4規格（21〇Χ2()7公釐）The right to touch, dance this is not more as the following projection conditions or mode power fractal example to explain the hole ί (Ν = point size is about 9.3 microns and the value: ^ = 28 物 纯 2—-borrowed in the case of E This is achieved by shifting the quasi-single-mode fiber to the multi-mode fiber and shifting the monofilament fiber of the multi-mode fiber. Moderately closed projection conditions are closed, and the peak multi-mode fiber volume is about the fiber tail on the mandrel. The light and Nami around the peach mandrel diameter mandrel to produce a 3G micron dot size and a numerical aperture of 0.13. Overfill projection can be achieved using a step-index multimode fiber as the fiber tail lobe, which The diameter of the stamen is larger than the numerical aperture of the microphysin. The numerical aperture is larger than 0.3. Example: Use the device in Figure 1 for measurement. Switch 2 is JDS, Dp8T switch PN: SC1618-D2SP SO6B0366. Repeat the test, and switch 2 uses JDS. Switcher, lx2 switcher pn: sw12-Z000311 SN: JC0349 91, and 1x8 switcher PN: SB0108-Z000329 SN: GB029604. The wearable minus 20 is JDS, PN: HA9-Z046 SN: KC000660. Use four Different projection conditions to measure the frequency of 62.5 micron core, 125 micron outer diameter fiber The detailed description is as follows: • Standard overfill is defined by TIA / EIA FOTP; • Moderately limited projection conditions provide 30 micron dots by winding 5 turns of a 50 micron core fiber on a 5 face diameter mandrel and Achieved; 4. The paper size is applicable to China National Standard Bi (CNS) Λ4 specification (21〇 × 2 () 7mm)

投射 DP8T 1x2 1x8 30微米 -19%/-8% ~23%/-6% 一48%/-15% 4微米偏移 -11%/-6% -6%/-3% 經濟部中央標準局兵工消汸合汴让‘印:^ 本纸張尺度適用中S3家標準（CMS )八4规格 - 20: - 21! ~31%/-15% —33Projection DP8T 1x2 1x8 30 microns -19% /-8% ~ 23% /-6%-48% /-15% 4 microns offset -11% /-6% -6% /-3% Ministry of Economy Central Standards Bureau Ordnance elimination and integration: '^: This paper size is applicable to S3 standards (CMS) 8-4 specifications-20:-21! ~ 31% /-15% —33

•限制投射條件籍由偏移鮮階 對於62. 5微米心蕊光纖4微米而形成；千早拉先誠相 形成。·非纽做_由姻鮮階職射率單模光纖而 + j試結果顯示於表1中。列出每—投射條件以及每-二』形式與參考分接頭㈣紐百分比。由不 量測頻帶寬度之差值百分比列於表1中最後一攔 (W)投射並綱讀長下作·〗。賴早拉先纖 表1 過度填滿 1%/5°/〇 1%/1% 4%/2°/〇 可變衰減 1%/5% 0%/1% -l%/〇% j 在系統端部處衰減器影響顯示為相當小，在所有情況 情i部份切換器顯示為低差值百分比，特別是過 總之，本發明藉域維光學__提供—種多種波 組合光源以及財錄投射條件，因而去除開放空氣整㉖• Restricted projection conditions are formed by shifting the fresh order to 62.5 μm core fiber 4 μm; Chihaya pulls the first phase to form. · Non-Finished _ From the single-mode fiber with high-efficiency rate and + j test results are shown in Table 1. List the per-projection conditions and the percentage of each-to-two form and reference tap. The percentage of the difference between the non-measured frequency band widths is listed in the last stop (W) projection in Table 1 and the outline is read as follows. Lai Zao Xian Xian Fiber Table 1 Overfilled 1% / 5 ° / 〇1% / 1% 4% / 2 ° / 〇 Variable attenuation 1% / 5% 0% / 1% -l% / 〇% j in The effect of the attenuator at the end of the system is shown to be quite small. In all cases, the switch of the part i is displayed as a low percentage difference, especially in short, the present invention provides a variety of wave-combined light sources and financial resources. Recording projection conditions, thus removing open air

試裝置進行全部測試。 T 本發明亦提供—種使職維光學切換技術之方式 21OX 297公浼 479135 經濟部中央嘌法〈工·;!ίί含泎.士··'!7;^ A7 B7 五、發明説明（了） 〜 °大而經由一次連接至測試裝置，而能夠進 二列如，光學時間領域反射儀_R)或差分模 UMD)調能觸由將其連接至切_其他端璋而盘 頻寬以及衰減合併量測。 、 此設計去除光學分独及使料—電子裝置滅以為 兀件。-鱗接提供機能以切換於各紐射條件，各種波 ，以及各f量咖不需要暴露於空氣中光學元件。其亦顯 敍援動態範圍1:測以消除暴露於空氣巾光學線路之功率 損耗已知的動恶範圍為放置於量測路徑中同時保持訊 比而能進行量測之衰減值。 、卞 量測系統動態範圍直接地轉變為能夠進行量測之光 長度。 、 '' 熟知此技術者了解本發明能夠作各種變化及改變但是 並不會脫離本發明之精神及範圍。這些變化及改變均含蓋 於下列申請專利範圍内。 本纸乐尺度適用中國國家橾準（CNS ) Λ4規格（210X 297公釐） (請先閲讀背面之注意事項再填寫本頁)Test device for all tests. T The present invention also provides a way to use professional optical switching technology 21OX 297 public 479 135 135 Central Purity Law of the Ministry of Economic Affairs <! ·! Ί 泎. 士 · '! 7; ^ A7 B7 ) ~ ° large and can be connected to the test device through one time, and can enter two columns such as, optical time domain reflectometer_R) or differential mode UMD). Attenuation combined measurement. 5. This design eliminates optical separation and makes materials-electronic devices think that they are obsolete. -Scale connection provides the function to switch to various radiation conditions, various waves, and each element need not be exposed to air optical elements. It also shows that the dynamic range of measuring aid 1: measuring to eliminate the power loss of the optical line exposed to the air towel. The known dynamic range is the attenuation value that can be measured while being placed in the measurement path while maintaining the signal ratio. , 卞 The dynamic range of the measurement system is directly converted to the length of light that can be measured. Those skilled in the art understand that the present invention can make various changes and changes without departing from the spirit and scope of the present invention. These changes and modifications are covered by the following patent applications. This paper scale is applicable to China National Standards (CNS) Λ4 specifications (210X 297 mm) (Please read the precautions on the back before filling this page)

Claims (1)

479135479135 經濟部中央標舉局負工消^合“ 、種以彳波導纖軌學特性之裝置，其包含： =光予切換為，其具有N個輸入端埠以及至少—個 端埠； . 1固輸出 一組多個雷射或光線發射二極體光源，每一 學地叙合至N個輸入端淳之—端蜂； 早7^光 端^^學切換H，其具有至少—個輸人端埠以及Μ個輪出 、、且夕们光線感測益，每—感測器光學地搞合至 學切換，Μ個輸出端崞之—端埠;以及 弟—先 光線量測構件光學地_合以接收光線感靡任何 線，-個參考麵纽縫賴賴長度 ★ 合於弟-切翻至少—個輸出端埠與第二城器至少= 輸入端埠之間；其中 第-及第二切鋪作為健通過其巾光_之功率分 2. 依據申請專利範圍第1項之裝置，其中多模光纖進行量測 以及投射進人乡模先贿辨分狀點大似及數值孔徑 足以將功率投射進人所有錢光纖允許之模。 3. 依據中請翻範賺項之裝置，其巾錄光纖進行量測 乂及技射進人夕模先纖模功率分佈之點大小以及數值孔徑 被限制使得乡模賴—些允許之模解運載功率。 4·^ί中”她圍第3項之裝置，其巾預先選擇數目雷射 為單核田射，其提供光線之點大小在8微米至3〇微米範圍内 Ο 5·依據申請專利範圍第丨項之裝置，其巾更進〜步包含可變 &amp;纸&amp;尺度適用中_家縣7^以4胁01^297^ -----h--Γ-^ --------, '订------In - &quot;_ (請先閲讀背而之注意事項再填寫本頁) 申請專利範圍The Central Ministry of Economic Affairs has designated the Bureau's work elimination and "devices based on the characteristics of 彳 waveguide fiber optics, which include: = light to switch to, it has N input port and at least one port; Output a group of multiple laser or light-emitting diode light sources, each of which is grouped to N input terminals, Chunzhi-Terminal; early 7 ^ optical end ^^ Switching H, which has at least one input end The port and M turn out, and the light sensing benefits, each sensor is optically coupled to the learning switch, the M output terminal is one of the port; and the first-the first light measurement component optical ground_ Any line can be touched by receiving light, a reference plane depends on the length of the stitch ★ At least-cut through at least-between the output port and at least the second port = input port; of which-and second The cutting power is used to pass the power of the towel. 2. The device according to item 1 of the scope of patent application, in which the multi-mode optical fiber is measured and projected into the human mode. The power is projected into the mode allowed by all the people's optical fiber. The point size and numerical aperture of the optical fiber for the measurement of the optical fiber and the power distribution of the fiber into the human model are limited, and the country model depends on some of the allowed modes to resolve the carrying power. Device, the number of lasers of the towel is preselected as a single-core field laser, and the point size of the light provided is in the range of 8 micrometers to 30 micrometers. 5 · According to the device of the scope of patent application, the towel further includes Variable & paper &amp; scales applicable _jiaxian 7 ^ to 4 threats 01 ^ 297 ^ ----- h--Γ- ^ --------, 'order ------ In-&quot; _ (Please read the precautions before filling this page) Apply for a patent 經濟部中央梂準局貝工消費合作社印製 化哀減H光學軸合進人光線路徑啟始於_個光源處以及 終止於一個感測器處。 6. 依據申請專利範圍第！項之裝置，其中光線量測方式為量 測被測試多模光纖之頻寬。7. 依射請專·圍幻項之裝置，其中光線制方式為量 測被測試多模光纖之衰減。 8·依，”專·_丨項之裝置，其巾更進—步包含第三 切換器，其具有至少一個輸入端埠以及至少兩個輸出端谭； 及其中 ’ 第三切換器至少兩個輸出端琿之—個端4光學地麵合至第 一切換器輸人端相及第^糾至少兩個輸出端淳之一 個端埠光學地輕合至第二切換器之輸出端琿。 ϋίίΐ專利細第1項之裝置，其中第—或第二切換器 1 〇.依據申請專利範圍第！項之裝置，其中更進一步包 :自動地切換於第一耦合器N個輸入端埠任何兩個端埠之 11.依據申請專利範圍第項之任何一項裝置 二===動地切換於第二切換器細輸出端痒之Printed by the Central Laboratories of the Ministry of Economic Affairs, Shelley Consumer Cooperative, the optical path of the optical axis of the H-reduction H light path starts at one light source and ends at one sensor. 6. According to the scope of patent application! Item of the device, wherein the light measurement method is to measure the bandwidth of the tested multimode fiber. 7. The device is designed according to the project, in which the light system is used to measure the attenuation of the tested multimode fiber. 8. According to the "specialized" device, the step further includes a third switch, which has at least one input port and at least two output terminals; and the third switch has at least two The output terminal—each terminal 4 is optically connected to the input terminal of the first switch and one terminal of at least two output terminals is optically closed to the output terminal of the second switch. Ϋίΐpatent The device according to item 1, in which the first or second switcher 1. According to the item in the scope of patent application, the device further includes: automatically switching to any two terminals of the N input ports of the first coupler. Port 11. According to any one of the items in the scope of the patent application, the second device === dynamically switches to the fine output terminal of the second switch. (請先閱讀背面之注意事項再填寫本頁) 卜訂----- if(Please read the notes on the back before filling this page)