Distributed feedback laser device and method for manufacturing the same
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsTohru Takiguchi, Yoshihiko Hanamaki
Life of this patent
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Abstract
A distributed feedback laser device includes a semiconductor base having a ridge waveguide structure projecting from its principal plane. The ridge waveguide structure extends with a predetermined width from one edge of the semiconductor base to an opposite edge. A diffraction grating layer is confined within the ridge structure. The ridge waveguide structure is formed by etching using an SiO2 film and a resist film as masks so that the diffraction grating layer is produced with substantially the same width as, or a less width than, the width of the ridge waveguide structure. A λ/4 shift diffraction grating or a chirped diffraction grating is preferably employed.
Claims6
A distributed feedback laser device comprising:
- a semiconductor structure including
- a semiconductor base defined by two opposing, general parallel, upper and lower principal planes and including a plurality of semiconductor layers adjacent the upper principal plane for emitting light,
- a ridge waveguide structure projecting from the upper principal plane of said semiconductor base and having a width, and
- a diffraction grating layer resonating with the light emitted from said plurality of semiconductor layers, said ridge waveguide structure extending from a first end of said semiconductor base to an opposite second end of said semiconductor base, and said diffraction grating layer having a plurality of grating elements arranged from the first end of said semiconductor base to the second end, said grating elements each having a width less than the width of said ridge waveguide structure and being confined within said ridge waveguide structure.
A method of manufacturing a distributed feedback laser device comprising:
- forming on a semiconductor substrate a plurality of semiconductor layers for emitting light;
- forming on said plurality of semiconductor layers a diffraction grating layer having a plurality of grating elements, the grating elements having a width, including forming said diffraction grating layer using as masks an SiO2 film having a plurality of film elements, each film element being wider than the width, and a resist film comprising a slit opening said film elements to the width;
- and
- forming, by etching said diffraction grating layer without etching said plurality of semiconductor layers, a ridge waveguide structure with said plurality of grating elements confined within said ridge waveguide structure.
Dependencies are inferred from the claim text.