Integrated laser-diode voltage driver for 20-Gb/s optical systems using 0.3-mym gate length quantum-well HEMT's.

An integrated laser-diode voltage driver (LDVD) making use of enhancement/depletion AlGaAs/GaAs quantum-well high electron mobility transistors (QW-HEMT's) with gate lengths of 0.3 mym has been developed. Its large signal bandwidth is 12 GHz. Eye diagrams of the output signal at bit rates up to 8 Gb/s show an opening similar to that of the input signal. Supporting material is given indicating that the LDVD might operate at bit rates up to 20 Gb/s. The maximum output current is over 90 mA; the maximum modulation voltage of 800 mV corresponds 40-mA modulation current for a laser diode with 20-Ohm dynamic resistance. The power consumption is less than 500 mW.