Research/Patents/US 5455421
US 5455421

INFRARED DETECTOR USING A RESONANT OPTICAL CAVITY FOR ENHANCED ABSORPTION

Assignee

MASSACHUSETTS INSTITUTE OF TECHNOLOGY A MA CORP

Filed

Aug 13, 1985

Granted

Oct 3, 1995

Location

Cambridge MA (Draper Lab/MIT)

Abstract

A photodetector for detecting optical irradiation at a predetermined wavelength is provided with an integral, resonant optical cavity by forming a plurality of layers of material on a metallic reflector backing, the total optical thickness of those layers being an odd multiple of one-quarter of the predetermined wavelength. One of those layers is an active (i.e. optically-absorptive) semiconductor material. When the materials are deposited, that absorbing layer is formed at a level in the cavity including a region of peak optical field. As a result of the enhanced absorption provided by the resonant structure, the active layer may be very thin (i.e., less than one-tenth of a wavelength thick), yielding many beneficial results.

Source: Google Patents

35 USC §181 Secrecy Order

Imposed

Jun 15, 1987

Rescinded

Feb 17, 1995

Duration

7 years, 8 months

Inventor

  • 1DAVID L. SPEARS

Sensitive facility: Cambridge MA (Draper Lab/MIT)

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Back to patent indexSource: USPTO 35 USC §181 secrecy order records