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.