Abstract

Semiconductor lasers under direct current modulation exhibit transient frequency chirping that leads to dynamic line broadening of a single longitudinal mode by several orders of magnitude compared to the cw linewidth. For a single-frequency semiconductor laser, unless dispersion-shifted fibers are used, the ultimate performance limitation is set by the transient chirp.¹ Recently, considerable attention is being paid^1-5 to the frequency chirp and its minimization. Of particular interest is the time-averaged power spectrum that no longer remains Lorentzian under current modulation but acquires an asymmetric two-peak structure.²

© 1985 Optical Society of America