| 摘要 |
PROBLEM TO BE SOLVED: To obtain a pulse optical source which is possessed of an optical resonator short in length and capable of being elongated in optical pulse repetition time interval by a method wherein a semiconductor laser which oscillates in a single wavelength and an optical resonator which displays resonance characteristics through a multiple interference are connected together in series. SOLUTION: An optical waveguide layer 12 is formed of an InGaAsP mixed crystal 1.3μm in band gap wavelength on an n-InP layer 13, an active region 16 is formed of an InGaAsP mixed crystal 1.55μm in band gap wavelength thereon, and a diffraction grating 15 of the InGaAsP mixed crystal 1.3μm in band gap wavelength is formed on the active region 16. An InP clad layer 11 and an electrode 14 are formed for the formation of a distributed feedback laser, wherein an antireflection coat 19 is provided to the end face of the laser so as to enable it to oscillate in a single mode, and a diffraction grating 17 is formed on a part of the optical waveguide layer 12. Therefore, a waveguide- type Fabry-Perot resonator composed of the diffraction grating and the end face 18 of the optical waveguide coated with a high reflection film to serve as a reflecting mirror is formed, and an optical resonator can be lessened in length and enhanced in optical pulse repetition time interval.
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