1.3-MU-M STRAINED MQW-DFB LASERS WITH EXTREMELY LOW INTERMODULATION DISTORTION FOR HIGH-SPEED ANALOG TRANSMISSION

The intermodulation distortion and the noise characteristics of 1.3-mu m strained multiquantum-well distributed feedback (MQW-DFB) lasers ha ve been investigated under the modulation frequency of 1.9 GHz in conn ection with the device structure, In this study, a strained MQW with s train compensated layers has been introduced in order to increase in t he quantum-well number and well width, This causes increase in the dif ferential gain, resulting in increase of the resonance frequency (fr). The fr as high as 5.1 GHz/mW(1/2) has been obtained which is in good agreement with the theoretical calculation. In addition to the straine d MQW structure, a new buried heterostructure entirely grown by MOCVD, named as FSBH (facet selective growth buried heterostructure), has be en developed to minimize the leakage current which degrades L-I charac teristics at high bias current causing the high distortion, The third- order-intermodulation distortion (IMD3) of -88 dBc and relative intens ity noise (RIN) of -152 dB/Hz have been obtained under a two-tone test at 1.9 GHz. This suggests that this newly developed laser is quite su itable for high-speed subcarrier multiplexing transmission.