Distributed feedback type semiconductor laser device and method of manufacturing the same
AssigneeFurukawa Electric Co., Ltd.
InventorsMasaki Funabashi, Akihiko Kasukawa
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Abstract
Disclosed are a gain coupled distributed feedback type semiconductor laser device which has a high single-mode yield and a smaller variation in the oscillation threshold current and luminous efficiency, and a method of manufacturing the same. The semiconductor laser device has a gain or loss which periodically changes, and comprises a cavity; and a diffraction grating formed in the cavity in such a way that an absolute value of a gain coupling coefficient in a vicinity of at least one of facets of the cavity is smaller than an absolute value of a gain coupling coefficient in the other area.
Claims6
A gain coupled distributed feedback type semiconductor laser device comprising:
- a cavity having facets at both ends thereof;
- a first region which is located in said cavity and having a diffraction grating with a predetermined period and being formed in said cavity between the facets and in which at least one of a gain and a loss of a laser beam in a propagation direction thereof periodically changes;
- and
- a second region located near both of the facets of the cavity and excluding the first region, the second region having an absolute value of a gain coupling coefficient smaller than that of the first region, a length of said second region being greater than said predetermined period.
A gain coupled distributed feedback type semiconductor laser device comprising:
- a cavity having facets at both ends thereof;
- a first region which is located in said cavity and having a diffraction grating with a predetermined period and being formed in said cavity between the facets and in which at least one of a gain and a loss of a laser beam in a propagation direction thereof periodically changes;
- and
- a second region located near at least one of the facets of the cavity and excluding the first region, the second region having an absolute value of a gain coupling coefficient smaller than that of the first region, a length of said second region being greater than said predetermined period.
Dependencies are inferred from the claim text.