Semiconductor laser device
First Claim
1. In a semiconductor laser device, an optical confinement region constituted by at least first, second, third and fourth semiconductor layers successively laminated on a predetermined semiconductor substrate, and a fifth semiconductor layer burying at least said second, third, and fourth semiconductor layers at each side face thereof which extends in parallel to the propagating direction of the laser ray, said second semiconductor layer having a relatively small refractive index as compared with that of said third semiconductor layer, said first and fourth semiconductor layers being of conductivity types opposite to each other and having relatively small refractive indexes as compared with that of said second and third semiconductor layers, said fourth and second semiconductor layers having respective band gaps which are relatively large as compared with that of said third semiconductor layer, and the fifth semiconductor layer having a smaller refractive index and a larger band gap than at least those of said third semiconductor layer, wherein difference in the band gap at least between said second semiconductor layer and said third semiconductor layer is selected not smaller than 0.15 eV.
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Abstract
A semiconductor laser device is capable of producing an increased optical output power with improved optical characteristics without being subjected to mode distortions in the output beam, while retaining advantageous features inherent to a semiconductor laser device of a buried heterostructure. The semiconductor laser device comprises an optical confinement region which is constituted by at least first, second, third and fourth semiconductor layers successively laminated on a predetemined semiconductor substrate. The second semiconductor layer has a relatively small refractive index and a relatively wide band gap as compared with those of the third semiconductor layer, while the first and the fourth semiconductor layers which are of the conductivity types opposite to each other have relatively small refractive indexes as compared with the second and the third semiconductor layers. The band gaps of the fourth and the second semiconductor layers are relatively large as compared with that of the third semiconductor layer. Difference in the band gap at least between the second and the third semiconductor layers is not smaller than 0.15 eV.
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Citations
15 Claims
- 1. In a semiconductor laser device, an optical confinement region constituted by at least first, second, third and fourth semiconductor layers successively laminated on a predetermined semiconductor substrate, and a fifth semiconductor layer burying at least said second, third, and fourth semiconductor layers at each side face thereof which extends in parallel to the propagating direction of the laser ray, said second semiconductor layer having a relatively small refractive index as compared with that of said third semiconductor layer, said first and fourth semiconductor layers being of conductivity types opposite to each other and having relatively small refractive indexes as compared with that of said second and third semiconductor layers, said fourth and second semiconductor layers having respective band gaps which are relatively large as compared with that of said third semiconductor layer, and the fifth semiconductor layer having a smaller refractive index and a larger band gap than at least those of said third semiconductor layer, wherein difference in the band gap at least between said second semiconductor layer and said third semiconductor layer is selected not smaller than 0.15 eV.
Specification