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:
Aug. 04, 1998
Filed:
Apr. 10, 1996
Masayuki Yamaguchi, Tokyo, JP;
Mitsuhiro Kitamura, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A wavelength tunable semiconductor laser includes an active region including an active layer generating an optical gain by injection of a current, a phase control region including a tuning layer generating variation of a refraction index by injection of the current, and a distributed Bragg reflector region including a tuning layer generating variation of a refraction index by injection of the current. The active region, the phase control region and the distributed Bragg reflector region are arranged in alignment in a resonance direction. A diffraction grating is provided in the vicinity of the tuning layer of the distributed Bragg reflector region. The wavelength tunable semiconductor laser includes a device for uniformly injecting a current to the phase control region and the distributed Bragg reflector region. The optical confinement factor to the tuning layer of the phase control region is greater than an optical confinement factor to the tuning layer of the distributed Bragg reflector type.