具腔內色散補償功能之波長可調自饋增益開關半導體雷射

Abstract

本文報導如何利用一商品型高功率半導體雷射(1.3um), 繞射光柵,透鏡, 狹縫型反射鏡組合成具色散補償功能之雷射外腔,利用外腔光回授形成自 饋增益開關半導體雷射.在連續波操作下,此雷射之單模波長調諧之範圍大 於 26nm, 且其旁模抑制比(side-mode suppression ratio,即SMSR)大 於30dB. 在增益開關操作下,無回授光時,脈衝寬度約40ps;經調整腔內色 散補償延遲線,在最佳狀況下所得到之最短脈衝寬度約9.1ps,脈寬-頻寬乘 積(time band- width product)為轉換極限的1.89倍,其波長調諧範圍大 於25nm,旁模抑制比約30dB.對很多應用而言,此光源將是相當具潛力的. In this thesis, we describe the construnction and the characterzation of a wavelength-tunable gain-switched laser diode with intra-cavity dispersion compensation. The system consists of a commerical high-power laser diode (1.3um), and a folded dispersive delay line consisting of a grazing incidence diffration grating, and a lens, a strip mirror and a translat- able lens-strip mirror assembly. In continuous wave (cw) operation, the tuning range of the laser is 26nm with a side- mode suppression ratio better than 30dB. In self-seeded and gain-switched operation, we have generated 9.1ps pulses with wavelength tunability of 25nm. The side-mode suppression ratio is about 30dB. This novel laser system should be very useful for a number of applications.