Efficient direct locking of colliding pulse mode-locked lasers on semi-insulating substrate at 1.5 μm

InP based colliding pulse mode locked laser synchronized by electrical subharmonic hybrid mode locking

“…Colliding Pulse Mode Locked Lasers (CPM) offer many advantages compared to other mode locked lasers providing relatively stable and better pulse-shaped mode-locking operation [1,2,4]. In this paper, we report for the first time the electrical subharmonic hybrid mode-locking (SHML) of a 3000 ,um buried heterostructure (BH) CPM laser fabricated through a single step MOVPE regrowth process with nearly transform-limited output.…”

A 40-GHz Colliding Pulse Mode-Locked Semiconductor Laser

“…[1−4] Compared with traditional Fabry-Perot two-section type mode-locked configurations, of which typical schemes incorporate a gain section and a saturable absorber (SA) that is integrated on a single substrate sharing the same multiple quantum well active region, [5−8] colliding pulse mode-locked (CPM) lasers place the SA section at the center of the laser cavity, taking advantage of the collision of two counter-propagating pulses in the SA section, which results in an absorption grating, leading to an enhancement of the saturable absorption and therefore more effective pulse shortening. [9−12] CPM lasers with 40-GHz repetition rate have been realized earlier in bulk [13] and multi-quantum well InGaAsP lasers [14] with picosecond pulses obtained. However, both the structures employed an all-active configuration, which would introduce potentially too much quantum noise resulting from amplified spontaneous emission (ASE) of the gain section, [15] leading to broad rf 3-dB line widths of several hundreds of kilohertz, deteriorating the device performance in pragmatic applications.…”