L. Zhai et al., LOCKING BANDWIDTH OF ACTIVELY MODE-LOCKED SEMICONDUCTOR-LASERS USING FIBER-GRATING EXTERNAL CAVITIES, IEEE journal of quantum electronics, 31(11), 1995, pp. 1998-2005
We demonstrate numerically that actively mode-locked semiconductor las
ers employing a linearly-chirped fiber grating in an external cavity c
an exhibit multiple drive frequency ranges of stable pulse generation,
and thus give a large locking bandwidth, The locking bandwidth define
s the range of RF drive frequencies over which the laser will generate
pulses with low timing jitter. The stable optical pulses are generate
d with leading or trailing subpulses due to optical energy circulating
within the fiber grating. The multiple stable ranges merge if loss is
introduced into the fiber-grating region. We also show that the locki
ng bandwidth can be improved if chirp is introduced into the grating,
Suprisingly, however, chirp of either sign improves the locking bandwi
dth.