Distributed feedback semiconductor laser
OwnerKoji Takahashiinventor
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Abstract
The gain coupled distributed feedback semiconductor laser includes an active layer and a diffraction grating which is provided in the vicinity of the active layer and has a plurality of light absorption layer periodically arranged along a resonator length direction. A relationship among energy h.nu. (h is Planck's constant, and .nu. is a frequency of induced emission light), forbidden band width E.sub.g of the light absorption layer, and energy band width .delta.E where free electrons are thermally distributed satisfies h.nu..gtoreq.E.sub.g +.delta.E.
Claims8
A gain coupled distributed feedback semiconductor laser, comprising:
- an active layer;
- and
- a diffraction grating provided in the vicinity of said active layer, and having a periodic light absorption layer which includes a plurality of light absorption sections periodically arranged along a resonator length direction, wherein:
- said periodic light absorption layer is formed of n type Al.sub.x Ga.sub.1-x As (0.ltoreq..times..ltoreq.1);
- a thickness of said periodic light absorption layer is larger than a de Broglie wavelength of an electron;
- and
- a difference between an energy h.nu. of an induced emission light and a forbidden band width E.sub.g of said periodic light absorption layer is about 0.13 eV or greater where h is Planck's constant and .nu. is a frequency of said induced emission light.
A gain coupled distributed feedback semiconductor laser, comprising:
- an active layer;
- and
- a diffraction grating provided in the vicinity of said active layer, and having a periodic light absorption layer which includes a plurality of light absorption sections periodically arranged along a resonator length direction, wherein:
- said periodic light absorption layer is formed of p type Al.sub.x Ga.sub.1-x As (0.ltoreq..times..ltoreq.1);
- a thickness of said periodic light absorption layer is larger than a de Broglie wavelength of an electron;
- and
- a difference between an energy h.nu. of an induced emission light and a forbidden band width E.sub.g of said periodic light absorption layer is about 0.08 eV or greater where h is Planck's constant and .nu. is a frequency of said induced emission light.
Dependencies are inferred from the claim text.