Ramasesha Bharat
Engineers at Echo Hl Way, Orange, CA

4896202, Jan 23, 1990

Jun 20, 1988

7/209244

Ramasesha Bharat - Orange CA
Michael D. Petroff - Fullerton CA

Rockwell International Corporation - El Segundo CA

N01L 2912, G01J 100, G01T 122

357 30

An edge illuminated impurity band conduction detector includes an extrinsic semiconducting IR-active layer with a first conductivity type impurity concentration high enough to create an impurity energy band. An intrinsic semiconducting blocking layer includes first and second conductivity type impurity concentration low enough that substantially no charge transport occurs by an impurity conduction mechanism. The IR-active and blocking layers are positioned between first and second contacts such that an electrical potential applied to the contacts creates an electric field across the layers. The detector is oriented such that the electromagnetic energy impinges on an edge of the IR-active layer and propagates in the IR-active layer in a direction substantially orthogonal to the applied electric field, the IR-active layer extending in the orthogonal direction for at least the absorption length of the electromagnetic energy. The detector may further include an extrinsic semiconducting buffered layer positioned with the IR-active layer between the blocking layer and the buffered layer, the buffered layer having a first conductivity type impurity concentration high enough to create an impurity energy band and a second conductivity type impurity concentration high enough that first conductivity type carriers injected into the buffered layer recombine with ionized first conductivity type impurities. In this embodiment, the IR-active layer further includes a second conductivity type impurity concentration low enough that first conductivity type carriers photogenerated in the IR-active layer can drift through the IR-active layer without recombining with ionized first conductivity type impurities.

4757210, Jul 12, 1988

Mar 2, 1987

7/020418

Ramasesha Bharat - Orange CA
Michael D. Petroff - Fullerton CA

Rockwell International Corporation - El Segundo CA

H01L 2714

250578

An edge illuminated optical detector array includes a series of two or more detectors which operate under an applied electric field. Each detector includes an extrinsic semiconducting active layer with a first conductivity type impurity concentration high enough to create an impurity energy band, and an intrinsic semiconducting blocking layer in which substantially no charge transport occurs by an impurity conduction mechanism. The detectors are positioned relative to one another such that optical energy incident on the array and directed substantially orthogonal to the applied electric field impinges on the first detector in the series and the portion of the optical energy which is transmitted by each detector is directed to the succeeding detector in the series. In this manner, the spectral content of the optical energy impinging on each detector is modified by the spectral transmission characteristics of the preceding detectors. In a solid state photomultiplier detector embodiment, each detector also includes an extrinsic semiconducting buffered layer having a first conductivity type impurity concentration which is high enough to create an impurity energy band and a second conductivity type impurity concentration which is high enough that first conductivity type carriers injected into the buffered layer recombine with ionized first conductivity type impurities.

4962304, Oct 9, 1990

Dec 23, 1988

7/289133

Maryn G. Stapelbroek - Santa Ana CA
Michael D. Petroff - Fullerton CA
Ramasesha Bharat - Orange CA

Rockwell International Corporation - El Segundo CA

H01J 4014, H01L 2912

250211J

Electromagnetic energy is detected by providing an extrinsic impurity-band semiconducting region with a first conductivity type impurity concentration high enough to create an impurity energy band. An intrinsic semiconducting blocking region is provided with first and second conductivity type impurity concentrations which are low enough that substantially no charge transport occurs by an impurity conduction mechanism. An electrical potential is applied to the impurity-band and blocking regions to create an electric field across the regions, then the regions are exposed to electromagnetic energy to generate intrinsic charge carriers in the regions. The electrical current induced in the regions as a result of the intrinsic charge carrier generation is measured.

4038565, Jul 26, 1977

Oct 3, 1974

5/511861

Ramasesha Bharat - Orange CA

H03K 2136

307225C

A CCD with N bits is clocked at a frequency f, which may be either constant or variable over a wide range. Meanwhile, a charge introduced into the first bit at t = 0 reaches the nth bit, n clock periods later, namely, at t = n/f. If this charge is sensed to give an output signal and the signal is fed back to introduce a charge again into the first bit, then a periodic output is obtained with pulses spaced every n/f seconds; the output frequency is therefore, 1/n times the input clock frequency. Output frequencies f, f/2, f/3,. . . f/N can be obtained by selecting n. The system includes the following structure: 1. A tapped N-bit CCD delay line. 2. Initial charge injection method. 3. Charge sink. 4. n - selector (n = 1, 2, 3,. . . N). 5.

3975753, Aug 17, 1976

Nov 8, 1974

5/522162

Ramasesha Bharat - Orange CA

H01L 2978, H03K 3353

357 24

A charge coupled device (CCD) wherein clocking or charge transfer at relatively high frequencies is obtained by the use of a slow-wave structure in the form of a metallized meander line fabricated on a relatively thin region of silicon dioxide contiguously formed on the surface of a silicon semiconductor substrate.