The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 26, 1989
Filed:
Oct. 07, 1988
Mototaka Taneya, Tsukuba, JP;
Kosei Takahashi, Nara, JP;
Toshiro Hayakawa, Yokohama, JP;
Sadayoshi Matsui, Tenri, JP;
Mitsuhiro Matsumoto, Nara, JP;
Hiroyuki Hosoba, Tenri, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A semiconductor laser device comprising a first layer that is of a first conductivity type; a second layer that is disposed on the first layer, the second layer having a forbidden bandgap smaller than that of the first layer and having a refraction index larger than that of the first layer; a third layer that is of a second conductivity type; the third layer being disposed over the second layer, having a forbidden bandgap larger than that of the second layer, and having a refraction index smaller than that of the second layer; a fourth layer that functions as a quantum wall, the fourth layer being disposed between the second and third layers and the thickness of the fourth layer being the de Broglie's wavelength or less; and at least one striped mesa, the lower portion of which is constituted by the third layer, wherein the fourth layer has a forbidden bandgap that is larger than that of the energy of photons generated by the second layer, and moreover the fourth layer has the etching characteristics that are different from those of the third layer positioned just above the fourth layer.