| 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<SB>rep</SB>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 f<SB>0</SB>converted from the Bragg wavelength in the distributed reflecting mirror region among longitudinal modes of the mode synchronous semiconductor laser indicate f<SB>0</SB>+(f<SB>rep</SB>/2) and f<SB>0</SB>-(f<SB>rep</SB>/2). COPYRIGHT: (C)2008,JPO&INPIT
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