高质量的一级光栅1．55μmDFB激光器

High─quality 1. 55μm DFB Lasers with First─order Gratings

本文详细叙述了ＤＦＢ激光器的设计要点和新的工艺。采用一级全息光栅和二步液相外延法批量研制出高稳定单纵模工作的１．５５μｍ分布反馈激光器（ＤＦＢ—ＬＤ）。外延片成品率＞４０％。器件特性：２５℃时阈值电流２０ｍＡ，单面光功率＞１０ｍｗ，主边模抑制比ＳＭＳＲ达４３ｄＢ（λ／４相移光栅），谱线宽度△ν－２０ｄＢ＝０．３ｎｍ，调制速率＞１．８ＧＨｚ。可靠性测试显示：高温监测光谱稳定，２５°Ｃ时阈值退化率△Ｉｔｈ／ｔ＜０．３ｍＡ／ｋｈ，对应器件预估寿命将超过１０万ｈ。

The key points for DFB laser design and new technigue have been described in detail. Highly stable single logitudinal mode operation 1.55μm distributed feedback laser (DFB) has been developed by means of the two -step liquid phase epitaxy (LPE) and firstorder grating. The epitaxial wafer yield>40 %. Device specifications: the CW threshold current (25°C ) is 20 mA, optical power/facet>10 mW, SMSR is up to 43 dB. spectral width △ν-20dB= 0. 3nm, modulation speed>1. 8GHz. Reliablity test show that:spectrum remains stable at high temperature. Threshold degradation<0. 3 mA/kh at 25°C,this rate correspondsto an estimated lifetime of more than 105 h.