Semiconductor laser
AssigneeNEC Corporation
InventorsYoshiyasu Ueno, Hiroaki Chida
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Abstract
A semiconductor laser capable of producing a high optical output has a coating film applied to an exit end. The coating film has a refractive index (n1) which is large compared with the refractive index (neff) of a semiconductor waveguide. The refractive index (n1) and the refractive index (neff) satisfy the relationship: n12>neff.
Claims4
A semiconductor laser having a coating film composed of a single layer or a plurality of layers, on an exit end of a semiconductor laser waveguide, said coating film having at least one layer having a refractive index n1 which falls within a range of ±20% of:
- n 1 = n eff × 1 - R 1 ( 1 - R 1 ) 2
- where neff represents the effective refractive index of said semiconductor laser waveguide and R1 the reflectivity of said exit end.
A semiconductor laser having a coating film composed of a single layer or a plurality of layers, on an exit end of a semiconductor laser waveguide, said coating film having at least one layer having a refractive index n1 which falls within a range of ±10% of:
- n 1 = n eff × 1 - R 1 ( 1 - R 1 ) 2
- where neff represents the effective refractive index of said semiconductor laser waveguide and R1 the reflective of said exit end.
A semiconductor laser having a coating film composed of a single layer or a plurality of layers, on an exit end of a semiconductor laser waveguide, said coating film having at least one layer having a refractive index n1 which falls within a range of ±20% of:
- n 1 = n eff × 1 - R 1 ( 1 - R 1 ) 2
- where neff represents the effective refractive index of said semiconductor laser waveguide and R1 the reflectivity of said exit end, said coating film having a layer other than said layer having the refractive index n1, the other layer having a thickness according to:
- λ 2 n j
- where nj represents the refractive index of the other layer and λ the oscillation wavelength of the semiconductor laser.
A semiconductor laser having a coating film composed of a single layer or a plurality of layers, on an exit end of a semiconductor laser waveguide, said coating film having at least one layer having a refractive index n1 which falls within a range of ±10% of:
- n 1 = n eff × 1 - R 1 ( 1 - R 1 ) 2
- where neff represents the effective refractive index of said semiconductor laser waveguide and R1 the reflectivity of said exit end, said coating film having a layer other than said layer having the refractive index n1, the other layer having a thickness according to:
- λ 2 n j
- where nj represents the refractive index of the other layer and λ the oscillation wavelength of the semiconductor laser.
Dependencies are inferred from the claim text.