high current, high bandwidth laser diode current driverA laser diode current driver has been developed for free space laser communications. The driver provides 300 mA peak modulation current and exhibits an optical risetime of less than 400 ps. The current and optical pulses are well behaved and show minimal ringing. The driver is well suited for QPPM modulation at data rates up to 440 Mbit/s. Much previous work has championed current steering circuits; in contrast, the present driver is a single-ended on/off switch. This results in twice the power efficiency as a current steering driver. The driver electrical efficiency for QPPM data is 34 percent. The high speed switch is realized with a Ku-band GaAsFET transistor, with a suitable pre-drive circuit, on a hybrid microcircuit adjacent to the laser diode.
Copeland, David J. (EVI, Inc. Columbia, MD, United States)
Zimmerman, Robert K., Jr. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
August 15, 2013
January 1, 1991
Publication: In: Free-space laser communication technologies III; Proceedings of the Meeting, Los Angeles, CA, Jan. 21, 22, 1991 (A93-18923 05-74)