Suppressed carrier optical pulse train generation method and mode-locked semiconductor laser to implement this method

摘要

PROBLEM TO BE SOLVED: To provide a method of generating a carrier suppressed optical pulse train capable of varying a half value width of optical pulses configuring the CS (carrier suppressed) optical pulse train and being achieved by a compact apparatus with small power consumption.;SOLUTION: A distribution feedback semiconductor laser 100 is configured to include an optical modulation region 10, a gain region 12, a phase adjustment region 14, and a distributed reflecting mirror region 16. A constant current source 38 injects a current to the gain region via a p-side electrode 26 and an n-side shared electrode 32 to form an inverse distribution required for laser stimulation. In the optical modulation region, optical modulation required for revealing mode synchronization is carried out. A diffraction grating 18 is formed to the distributed reflecting mirror region. The CS optical pulse train with a repetitive frequency f_rep is generated by adjusting the effective refractive index of the phase adjustment region and of the distributed reflecting mirror region, so that two longitudinal modes whose frequencies are close to a frequency f₀ converted from the Bragg wavelength in the distributed reflecting mirror region among longitudinal modes of the mode synchronous semiconductor laser indicate f₀+(f_rep/2) and f₀-(f_rep/2).;COPYRIGHT: (C)2008,JPO&INPIT