The relationship between LD modulation bandwidths and other parameters is obtained through theoretical deducing and numeric simulating. Modulation characteristics under different relaxation oscillation frequencies, attenuation coefficients and parasitic parameters are analyzed. The results showed that the 3 dB bandwidths of LDs are just confined by the parasitic parameters when the effects of the parasitic parameters are excessive. So the effects must be overcome before optimize the active region and structure of LDs to realize high speed modulation. The measured maximum 3 dB bandwidths of planar buried LDs with buried polyimide double trenches and AlGalnAs ridge waveguide LD are 5 GHz and 8.5 GHz separately , and the modulation characteristics results of the two types of LDs are analyzed qualitatively.%通过理论推导和模拟计算,给出激光器调制带宽和其它参数之间的关系.分析了不同张驰振荡频率、衰减系数和寄生参数下的调制特性.结果表明当寄生参数过大时,激光器的3 dB调制带宽主要受寄生参数限制,因而只能在解决了寄生参数限制的前提下,通过对器件的有源区和结构进行优化才能获取高的3 dB调制带宽.对于制作的聚酰亚胺埋沟掩埋激光器和A1GaInAs脊型波导激光器其最大3 dB调制带宽分别为5 GHz和8.5 GHz,定性地解释了两类半导体激光器调制特性的测试结果.
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