Dynamic spectra of 1.3 micron InP lasers under Pseudo-random word modulation.

The dynamic spectra under low-duty-cycle pulse modulation, and 180 Mbit/s and 432 Mbit/s pseudo-random pulse modulation were studied for buried-heterostructure and channeled substrate InP lasers. The average dynamic spectra of these lasers differ from their DC spectra, and also show variation between low- duty-cycle pulse modulation and pseudo-random pulse modulation. Transient times of the average dynamic spectra of more than 4 ns were observed for some lasers. No variation in the average dynamic spectra among the pseudo-random pulses was observed at 180 Mbit/s and at 432 Mbit/s where the time slot is less than the spectral turn-on time.