光纖放大器於光纖感測及光纖迴路雷射之應用

Abstract

本論文的第一部分是提出一個S頻段的增益箝制摻鉺光纖放大器（Erbium-Doped Fiber Amplifier: EDFA）與一 S 頻段的單模光纖迴路型雷射。S頻段的增益箝制EDFA的光特性與其行為都在本文中被探討。而本S頻段的單模光纖迴路型雷射是利用一個S頻段的EDFA模組、一個光纖式法布里－珀羅（Fabry-Perot）可調濾波器、一段尚未泵激且較短的 EDF及一個反射鏡所組成。在操作波長在 1488.7 nm 至 1515.7 nm 之間，其輸出功率可達到10 dBm以上，而旁模壓抑比（Side-Mode Suppression Ratio: SMSR）最大可達 49.1 dB/0.05 nm。 在第二個部份，我們利用迴路型雷射架構的方式提出了S頻段的光纖感測實驗及一個藉由半導體光放大器（Semiconductor Optical Amplifier: SOA）的多點光纖感測技術。在S頻段的光纖感測實驗中，調整共振腔內 Fabry-Perot 波長分布，使各個相對應的FBG中心波長可以分別產生激發以作為感測用。而在多點感測的實驗中，藉著 SOA 非均相變寬的性質使得每個FBG均可產生雷射，在選擇適當耦合比例下的光耦合器，我們可以獲得更解析度較清晰的光訊號進而偵測多點的光纖感測系統。

In the first part of the thesis, we propose and investigate experimentally a gain-clamped S-band erbium-doped fiber amplifier (EDFA), a stable and single-longitudinal-mode oscillation of an S-band EDF ring laser. The behaviors and performances of the S-band amplifier have also been discussed in the text. Single-longitudinal-mode laser output can be realized by employing a Fabry-Perot filter and a saturable-absorber-based autotracking filter composed of an unpumped EDF and an optical reflector. The performance of output power is larger then 10 dBm and a side-mode suppression ratio (SMSR) is larger then 49.1 dB from 1488.7 to 1505.7 nm. In the second part of the thesis, we propose the S-band fiber sensor technique and a multiplexed fiber sensing system based on semiconductor optical amplifier (SOA). In the experiment of S-band fiber sensor system, the proposed laser lases at each wavelength of the FBG accordingly by tuning the Fabry-Perot filter. In the experiment of multiplexed sensing system, all lasing wavelengths based on the inhomogeneous broadening effect of SOA are accordingly the FBG central wavelength. Using properly coupling ratio, we can obtain the clearly optical signals.