Dynamic modulation of quantum devices

US5847435A · kind A · utility

Assignee

• The United States of America as represented by the Secretary of the Army · US

Inventors

• Arthur Ballato · Long Branch, US
• Richard H. Wittstruck · Howell, US
• Yicheng Lu · East Brunswick Township, US
• Mitra Dutta · Tinton Falls, US
• Jagadeesh Pamulapati · Eatontown, US
• Paul H. Shen · North Potomac, US

Key dates

• Filing date: Aug 9, 1996
• Grant date: Dec 8, 1998
• Expiry date: Aug 9, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G02F1/0128
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An MQW is fabricated such that at a particular level of purely mechanical ress/strain the optical properties of the MQW are altered by breaking the heavy and light hole degeneracy (splitting of the heavy and light holes in the valence band) of the MQW in the E-k domain. In a preferred embodiment of the invention ring electrical contacts are disposed on the MQW and the entire MQW structure, including electrical contacts is mounted on a piezoelectric substrate, with the proper crystallographic orientation and strain induced orientation, via an epoxy. In operation, a bias is applied to the MQW structure and the piezoelectric substrate. The bias causes quantum decoupling of the heavy and light holes; however, the bias also will cause the piezoelectric material to move, which will induce a strain on the MQW structure. This strain will, in turn, also induce a decoupling of the heavy and light holes, but to a greater degree than the decoupling induced by the electrical bias and therefore, the absorption of the MQW will altered, thereby polarizing optical signal incident to (or through) the device.