| 摘要 |
PROBLEM TO BE SOLVED: To improve the efficiency of the output characteristics of the laser light from an LD. SOLUTION: A semiconductor laser module 1 uses a fiber grating FG and a half value width W<SB>3l</SB>on the side toward shorter wavelengths from a central wavelengthλ<SB>3</SB>in the reflectance distribution of the fiber grating FG is made narrower than a half value width W<SB>3h</SB>on the side toward longer wavelengths from the central wavelengthλ<SB>3h</SB>. The half value width on the shorter wavelength side is not less than one thirtieth and less than that on the longer wavelength side, preferably, more than one fifth and less than half. The reflectance distribution of the fiber grating FG is one composed of a plurality of fiber gratings FG<SB>1</SB>and FG<SB>2</SB>, the central wavelengths of the laser light and the half value widths of which are different. The reflectance distribution of the fiber grating FG can be that of a chirped grating FGc, the central wavelength of the laser light and the half value width of which increase continuously. COPYRIGHT: (C)2004,JPO |
