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:
Sep. 10, 1991
Filed:
Mar. 24, 1988
John W Little, Jr, Wheaton, MD (US);
Richard P Leavitt, Silver Spring, MD (US);
Martin Marietta Corporation, Bethesda, MD (US);
Abstract
A quantum well semiconductor device that is responsive to optical energy and operates by resonant field ionization of quantum confined excitons and comprises a semiconductor device including a multi-layered semiconductor structure fabricated on the substrate and including at least two quantum well layers of mutually different widths separated from each other by a semiconductor barrier layer. Because of the different widths, the two quantum well layers have distinct and different electron and hole sub-band energies which when an external electric field is applied across the semiconductor structure, it is possible to bring the electron sub-bands of the wells into resonance, whereupon electrons tunnel back and forth through the barrier layer thereby altering the light absorption coefficient near the excitonic absorption feature. This mechanism provides a means to phase shift or modulate the light traversing through the device.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile