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:
Mar. 08, 2005
Filed:
Jun. 14, 2002
Mitsuhiro Matsumoto, Kashihara, JP;
Mitsuhiro Matsumoto, Kashihara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
There is provided a semiconductor laser element, which has a small capacitance outside a ridge portion and high response speed and is able to effect pulse oscillation with a satisfactory pulse waveform. On a GaAs substrate, there are provided an n-type buffer layer, an n-type first clad layer, an MQW active layer, a p-type second clad layer, a p-type etching stop layerthat has an energy bandgap smaller than that of this second clad layer, a p-type third clad layerthat constitutes a ridge portion and a p-type protective layer. On both sides in the widthwise direction of the ridge portion are laminated a p-type spacer layer, an n-type current light confining layer, an n-type current confining layerand a p-type flattening layer. On these layers is laminated a p-type contact layer. A depletion layer spreads into the spacer layerwhen a bias voltage is applied. Therefore, a capacitance between the spacer layerand the current light confining layeris reduced, and a response speed during the pulse oscillation of the semiconductor laser element becomes fast.