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. 29, 1992
Filed:
Sep. 12, 1991
Atsushi Takeuchi, Isehara, JP;
Shunichi Muto, Atsugi, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical semiconductor device comprises a first material layer having a first thickness and formed of a first semiconductor material having a first band gap; a first quantum level pair formed in the first material layer in correspondence to the first thickness with a first energy gap that corresponds to an energy of the incident optical beam to be modulated; a pair of second material layers each having a second, smaller thickness chosen to cause the tunneling of carriers through the second material layer, the second material layer being formed of a second, different semiconductor material having a second, larger band gap and provided at both sides of the first material layer; a third material layer having a third thickness larger than said first thickness and provided at least above or below the second material layer; a second quantum level pair formed in the third material layer in correspondence to the third thickness with a second energy gap that is smaller than the first energy gap; and a carrier annihilating part for annihilating the carriers from the second quantum level pair by inducing a stimulated emission of light having an energy identical with the second energy gap.