Patent ID: 6343088
Filing Date: 2002-01-29
Classification: H01S

Abstract:
A semiconductor laser module comprising:a semiconductor laser device having an emitting surface from which excited light is emitted and a reflecting surface opposite to said emitting surface, and an optical feedback medium for feeding optical power emitted from said emitting surface of said semiconductor laser device back to said semiconductor laser device based on a predetermined coupling efficiency and emitting part of said optical power, wherein said semiconductor laser device has at least a first multilayer coating formed on said emitting surface and having a reflectance of 10âˆ’4 to 10% at a central wavelength of reflection, and wherein said first multilayer coating has a reflection spectrum in the form of a curve having minimum values on both sides of the central wavelength of reflection, and said first multilayer coating has a wavelength characteristic that broadens a pulling width of said semiconductor laser device.