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US3821777A Expired / Lapsed US ⏱️ 0.0 years remaining

Avalanche photodiode

Assignee: Varian Medical Systems Inc
•
Filing: 1972-09-22
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Granted: 1974-06-28
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Expires: 1992-09-22
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Abstract

Abstract AN AVALANCHE PHOTODIODE, PARTICULARLY USEFUL FOR DETECTION OF INFRARED ENERGY IN THE WAVELENGTH REGION FROM 1 TO 2 MICRONS, INCLUDES AN ACTIVE EPITAXIAL LAYER OF A QUATERNARY IIIV ALLOY SUCH AS N-IN-1-YGAYP1-XASX. THE ACTIVE LAYER INTERFACES WITH A SECOND LATTICE MATCHED EPITAXIAL LAYER OF P-TYPE JUNCTION AL TO DEFINE A LATTICE MATCHED P-N JUNCTION THEREBETWEEN WHICH IS REVERSED BIASED, IN USE. THE ACTIVE LAYER HAS A DIRECT BANDGAP ENERGY LESS THAN THE PHOTON ENERGY OF THE INFRARED ENERGY TO BE DECTED FOR ABSORPTION OF THE PHOTONS TO BE DETECTED TO GENERATED ELECTRON-HOLE PAIRS. THE ACTIVE ALYER IS MADE OF A MATERIAL HAVING AN ENERGY DIFFERENCE BETWEEN THE LOWEST CONDUCTION BAND MINIMUM BAND THE NEXT HIGHER CONDUCTION BAND MINIMA EITHER X1 OR L1 WHICH IS GREATER THAN 1.1 TIMER THE DIRECT BANDGAP ENERGY OF THE ACTIVE LAYER, WHEREBY IMPROVED SIGNAL TO NOISE RATIO IS OBTAINED.

Inventors

  • 👤 L James

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 13:46
CPC Classifications
H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/225; H10F30/24; Y; Y10; Y10S; Y10S148/00; Y10S148/065; Y10S148/067; Y10S148/072; Y10S148/099; Y10S148/107

Claims Analysis

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References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-06-27 1977-12-27 1978-06-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-06-27 1981-12-27 1982-06-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-06-27 1985-12-27 1986-06-28 $7700.00 Window Closed / Lapsed

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