Turn-on Time Delay of Uncooled Semiconductor Laser Diode Subject to External Optical Feedback: Theoretical Analysis

In this paper, the effect of external optical feedback (EOF) on the turn-on time delay (t
_on
) of uncooled semiconductor laser diode (SLD) is investigated theoretically. The effects temperature of operation (T) and EOF on t
_on
are calculated according to their effect on threshold carrier density (N
_th
). The temperature dependence (TD) of N
_th
is calculated according to the TD of laser cavity parameters and not by the well-known Parkove relationship. Simulation results show that t
_on
increases as T increases due to increasing of N
_th
. In addition, t
_on
decreases as external reflectivity (r
_ext
) increases when the phase of reflected light is coherent. While at incoherent reflected light, t
_on
increases sharply around specified value of r
_ext
where this leads to inoperable case for SLD.