An InGaAsP 1.55 μm Mode-Locked Laser with a Single-Mode Fiber Output

Abstract

Mode-locked InGaAsP lasers emitting in the 1.3–1.6 μm wavelength region are attractive as potential sources for very-high bit-rate fiber communication applications. Previous mode-locking of InGaAsP lasers produced pulse widths of roughly 20 ps [1,2,3], at repetition rates as high as 10 GHz [1], Shorter pulses [4], and higher repetition rates [5] have been demonstrated only in AlGaAs lasers. In most reported mode-locked semiconductor laser structures, the output pulses are taken from a cleaved laser chip facet. In order to couple the pulses to a fiber, it is necessary to use some form of a laser-fiber mode-matching technique. This will, in general, add coupling losses (typically 3–5 dB) as well as coupling instabilities.