Colliding-pulse mode-locked semiconductor laser with a multimode-interference waveguide amplifier

摘要

We demonstrate numerically a novel colliding-pulse mode-locking (CPM) technique for semiconductor laser without using a saturable absorber. A multimode-interference (MMI) semiconductor optical amplifier (SOA) is used as the gain medium and the mode locker. Efficient pulse compression and stabilization of the two counter-propagating pulses are achieved based on the nonlinear-coupling effect, assisted with pulse collision, in the MMI SOA. Two initially different pulses tend to adjust each other, resulting in symmetric collision of two identical pulses. Such efficient pulse compression and stabilization mechanisms should lead to simple implementation of CPM semiconductor lasers.