| 主权项 |
1. A semiconductor laser module comprising:
a semiconductor laser outputting a laser light, output from an output facet side of a waveguide having a refractive index waveguide structure, via a lens system, the waveguide having, from a rear facet side opposite to the output facet and in an order of, a first narrow portion formed to be identical in width, a wide portion formed to be wider than the first narrow portion, a second narrow portion formed to be narrower than the wide portion, a first tapered portion being formed between the first narrow portion and the wide portion and increasing in width toward the wide portion, and a second tapered portion being formed between the wide portion and the second narrow portion and decreasing in width toward the second narrow portion, a width of the second narrow portion being within 2.0 μm to 5.0 μm, an inclination angle θ indicated as θ=arctan [(ΔW/2)/Lt2] being equal to or smaller than 0.6 degrees in a case where ΔW indicates a difference between a width of the wide portion and a width of the second narrow portion of the waveguide and Lt2 indicates a length of the second tapered portion, Ln2≧106θ−0.00681 (where 0.47<θ≦0.60), Ln2≧317θ−100 (where 0.32<θ≦0.47), and Ln2>0 (where θ≦0.32) holding true in a case where Ln2 indicates a length of the second narrow portion, and a length of the first narrow portion of the waveguide being equal to or greater than 30% of a cavity length defined by the output facet and the rear facet; and an optical fiber, the laser light output from the semiconductor laser being input to the optical fiber, the optical fiber having an optical feedback unit reflecting a predetermined wavelength of light, wherein the semiconductor laser is enclosed in a package together with one end of the optical fiber, and the optical feedback unit has a first optical feedback unit set at a predetermined reflection center wavelength determining an oscillation wavelength of the semiconductor laser and at least a second optical feedback unit. |
