Semiconductor laser device
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsKenji Ikeda, Kimio Shigihara, Yutaka Mihashi
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Abstract
A semiconductor laser device provided with a broad light waveguide through which a higher order transverse oscillation modes can propagate, includes at least one of laser facet having a high reflectance region having a width of about 1/5 to 1/2 of the width of the light waveguide located at a central portion thereof and a low reflectance region having a lower reflectance than the high reflectance region located at both sides of the high reflectance region whereby higher order modes of oscillation can be suppressed.
Claims7
In a semiconductor laser device having a light waveguide through which a higher order transverse mode of oscillation can propagate, a first facet through which laser light is emitted, and a second facet opposite the first facet on which a reflective coating is disposed, a relatively high reflectance coating having a width of about 1/5 to 1/2 of the width of said light waveguide disposed centrally on the first facet and a relatively low reflectance coating having a lower reflectance than said high reflectance coating disposed on the first facet at both sides of said high reflectance coating.
In a semiconductor laser including an internal light waveguide having a width and a thickness, the width being much larger than the thickness, the waveguide supporting multiple modes of oscillation for the generation of laser light, a first facet through which laser light is emitted, a second facet opposite the first facet on which a reflective coating is disposed, and a first coating disposed on the first facet having a relatively low reflectance and a second coating disposed on part of the first coating transverse to and centrally disposed relative to the width of the waveguide, the second coating having a relatively high reflectance and a width generally parallel to the width of the waveguide of about 1/5 to 1/2 of the width of the waveguide, whereby the higher reflectivity of the first facet at the central portion of the waveguide sustains the fundamental mode of oscillation in the laser and the lower reflectivity of the first facet outside the central portion of the waveguide suppresses higher order modes of oscillation in the laser.
Dependencies are inferred from the claim text.