发明名称 |
Photon-counting spatial light modulator with APD structure |
摘要 |
A photon-counting spatial light modulator that has an avalanche photodiode structure and is designed to operate in Geiger mode is sensitive to a single photon of light. An avalanche photodiode having an applied electric field is excited by an optical wave comprising one or more photons whose energies exceed the band-gap energy of the photodiode material. This localized electrical excitation alters the refractive index of the material through various effects, most notably the transient thermo-optic effect and the photorefractive effect. A second optical wave is incident during or shortly after the electrical excitation, and comprises photons whose energy is less than or nearly equal to the band-gap energy. This second optical wave is then used to read out the avalanche-induced variation in refractive index. This read out is most effective when the avalanche photodiode structure has partially reflective front and back surfaces and therefore forms a Fizeau interferometer in which the variation in refractive index causes localized variations in reflectivity.
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申请公布号 |
US5521743(A) |
申请公布日期 |
1996.05.28 |
申请号 |
US19930167292 |
申请日期 |
1993.12.16 |
申请人 |
ROCKWELL INTERNATIONAL CORPORATION |
发明人 |
HOLMES, RICHARD B.;BENNETT, GLENN T. |
分类号 |
G02F1/03;(IPC1-7):G02F1/03 |
主分类号 |
G02F1/03 |
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