INTEGRATED HFETS AND HFET LASERS UTILIZING CARBON DOPING

Carbon doping is used in the MBE growth of HFET's and the associated l aser to provide significant improvement in the contact resistance, The lower resistance enables CW operation of the integrated FET and laser combination as opposed to previous pulsed operation, Compared to the earlier Be-doped samples the threshold is lowered from 30 mA to 18 mA, the total slope efficiency and maximum power are increased to 0.7 W/A and 30 mW from 0.5 W/A and 6 mW respectively, and the 3 dB modulation bandwidth has been extended from 4 GHz to 10 GHz.