PASSIVE MODE-LOCKED SEMICONDUCTOR LASER DEVICE, AND OPTICAL CLOCK SIGNAL EXTRACTOR

摘要

PROBLEM TO BE SOLVED: To enable to extract a high-speed optical clock signal exceeding the upper limit speed of an electronic device, not depending on the polarization direction of an input optical signal.;SOLUTION: This is an MLLD device 200 which has a multielectrode semiconductor laser element 70 and a polarization rotator 32 in an optical resonator. The resonator length L of the optical resonator is so set that an optical pulse train occurring at frequent time intervals of a fraction of a natural number of the time required for light to go around once inside the optical resonator may be output outside the optical resonator. The multielectrode semiconductor laser element consists of a gain region 20 and a saturable absorber region 10, which are arranged in series. Into the gain region, a current is injected from a constant current source 36 via an n-side common electrode 26 and a p-side electrode 22 of the gain region. Meanwhile, the saturable absorber region is applied with inverse bias voltage from a constant voltage source 38 via the n-side common electrode and a p-side electrode 12 of the saturable absorber region. Optical guides 24 and 14 are interposed between a first clad layer 18 and a second clad layer 16 which are common to both regions.;COPYRIGHT: (C)2007,JPO&INPIT