可調單波長及多波長半導體外腔雷射在DWDM的應用

Abstract

本論文提出一新型的可調單波長及多波長外腔半導體雷射系統。藉由一個AR-coated半導體雷射、削角入射光柵與實驗室自製的V形條形鏡形成外腔，得到不同的單波長與雙波長輸出。其中單波長的部分，可調範圍為60 nm (1500 nm- 1560 nm)，旁模抑制比皆超過30 dB，並可高達45 dB；雙波長部分，藉著調整反射鏡橫向的位置，可分別得到不同間隔的雙波長及相同間隔不同雙波長的輸出，同時我們也量測了雙波長輸出時，功率隨時間變化的穩定度，其變化量在10-4 左右。更進一步地，利用液晶反射鏡（與交大電物所液晶實驗室合作）做為空間調制器，電控雷射不同波長的輸出，分別得到單波長、雙波長與三波長輸出。我們所量測到最寬的雙波長間隔為5.42 nm，最窄的為0.67 nm。最後，我們知道藉由設計液晶元件的規格，可獲得四波長甚至更多波長的輸出，以應用在DWDM光纖通訊系統中。

We demonstrate a new type of tunable single- and multiple- wavelength external cavity laser diode (LD) for DWDM applications. With a single-stripe mirror in the external cavity, the laser generates narrow-band (< 0.01 nm, instrument-limited) single-wavelength output tunable from 1500 to 1560 nm. The side-mode-suppression-ratio (SMSR) is higher than 30 dB and up to 45 dB. By using a V-shape double-striped mirror, narrowband dual-wavelength operation with tunable wavelength separation is realized. The peak-to-peak stabilities of the laser output power at the two wavelengths: □p/p □ 10-4 can be maintained for several hours. Furthermore, in our configuration, a liquid crystal pixel mirror is applied to be electronically tuning and switching. Dual-wavelength mode spacing can be as small as 0.67nm while the farthest mode spacing is 5.42 nm. Finally, it is possible to implement simultaneous oscillation of four or more wavelengths in our laser system.