Harry S Hier

6987306, Jan 17, 2006

Jul 17, 2003

10/621203

Ayub M Fathimulla - Ellicott City MD, US
Olaleye A. Aina - Columbia MD, US
Harry Stephen Hier - Sykesville MD, US

Epitaxial Technologies - Baltimore MD

H01L 27/14

257431, 257432, 257436, 257443, 257444, 257 80, 257 82

This invention describes an approach for monolithically integrating all the components of a photoreceiver—optical amplifier, optical band-pass filter, and photodiode module—on a single chip. The photoreceiver array employs unique optical amplifier and conversion technologies that provides the ultra-sensitivity required for free space optical communications networks. As an example, by monolithically integrating a vertical cavity surface emitting laser-diode (VCSEL) optical preamplifier with a photodiode receiver and related amplifiers and filters on the same chip, sensitivities as low as −47 dBm (62 photons/bit at 2. 5 Gb/s), along with an order of magnitude reduction in size, weight, and power consumption over comparable commercial-off-the-shelf (COTS) components can be demonstrated. In accordance with another aspect of the present invention, the concept of monolithic integration of optical amplifier with photodetector is extended to lasers, another amplifier and modulators covering ultra violet to very long wavelength infrared using the InP, GaAs, GaSb, InAs, InSb, SiGe, SiC and GaN etc based technologies.

6992319, Jan 31, 2006

Jun 24, 2002

10/176787

Ayub M Fahimulla - Ellicott City MD, US
Harry Stephen Hier - Sykesville MD, US
Olaleye A. Aina - Columbia MD, US

Epitaxial Technologies - Baltimore MD

H01L 29/15

257 20

Alternate layers of wide band gap and narrow band gaps of different kinds of semiconductors are used to form multiple channels of a FET. The channels are doped or formed as 2-DEG/2-DHG in narrow band semiconductor by charge supply layer in the wide band gap semiconductor. The different kinds of semiconductors form heterojunctions to confine the electrons/holes in separate thin spikes layers. A number of spikes (3–10 nm thick) of different doped or 2-DEG/2-DHG concentrations in various channels can result in overall electron concentration gradient such as a 1/xelectron/hole concentrations profile. Such an electron/hole concentration gradient can result in a linear variation of drain current with voltage to obtain a wide dynamic range.

7276723, Oct 2, 2007

Aug 18, 2005

11/205484

Ayub Mohammed Fathimulla - Forest-Hill MD, US
Harry Stephen Hier - Sykesville MD, US
Olaleye Adetord Aina - Columbia MD, US

Epitaxial Technologies - Baltimore MD

H01L 29/15

257 20, 257287, 257E29072

Alternate layers of wide band gap and narrow band gaps of different kinds of semiconductors are used to form multiple channels of a FET. The channels are doped or formed as 2-DEG/2-DHG in narrow band semiconductor by charge supply layer in the wide band gap semiconductor. The different kinds of semiconductors form heterojunctions to confine the electrons/holes in separate thin spikes layers. A number of spikes (3-10 nm thick) of different doped or 2-DEG/2-DHG concentrations in various channels can result in overall electron concentration gradient such as a 1/xelectron/hole concentrations profile. Such an electron/hole concentration gradient can result in a linear variation of drain current with voltage to obtain a wide dynamic range.

7339726, Mar 4, 2008

Dec 9, 2004

11/007951

Ayub Mohammed Fathimulla - Ellicott City MD, US
Harry Stephen Hier - Sykesville MD, US
Olaleye A. Aina - Columbia MD, US

Epitaxial Technologies - Baltimore MD

H01S 3/00

359344

A vertical cavity semiconductor optical photoamplifer (VCSOA) is used as a modulating retro-reflector (MRR) as a pixel in an array. The boundary of the cavity in the VCSOA forms a mirror for reflecting an incident light as an amplified output.

7605357, Oct 20, 2009

Mar 21, 2006

11/384909

Ayub Mohammed Fathimulla - Forest Hill MD, US
Olaleye Adetoro Aina - Columbia MD, US
Harry Stephen Hier - Sykesville MD, US

Epitaxial Technologies - Baltimore MD

H01J 40/14

250214R, 2502141

An array of photon counting phototoreceivers is constructed as an imager with micro-digitized pixels. Each photoreciever comprises a vertical cavity optical amplifier (VCSOA) as an optical amplifier, an avalanche photodiode as detector and an analog-to-digital converter (ADC) in an integrated structure. The ADC serves as a 1-bit digitizer and uses a resonant tunneling bipolar transistor RTBT. While the preferred embodiment of the invention have been described, it will be apparent to those skilled in the art that various modifications may be made to the embodiments without departing from the spirit of the present invention. Such modifications are all within the scope of the present invention.

20050082520, Apr 21, 2005

Oct 6, 2003

10/678801

Ayub Fathimulla - Ellicott City MD, US
Harry Hier - Sykesville MD, US
Olaleye Aina - Columbia MD, US

H01L029/06

257014000

An integrated dual wavelength quantum-well infrared photodetector has two absorption peaks of photo response. The structure has a standard quantum well to yield a peak photo response at one wavelength and a sub-well to yield a peak photo response at a second wavelength. The standard quantum well and the sub-well is separated by a barrier. The barrier-well-subwell-well barrier layers are structured periodically. Additional quantum wells and sub-wells may be added to yield a multi-wavelength infrared photodetector.

6407439, Jun 18, 2002

Aug 19, 1999

09/378212

Harry S. Hier - Sykesville MD
Olaleye A Aina - Columbia MD

Epitaxial Technologies, LLC - Baltimore MD

H01L 3100

257440, 257431

More than one photodetectors, each sensitive to different wavelengths, are integrated on a common semiconductor substrate. The different photodetectors can be stacked over one another or placed laterally on the common substrate. Gratings may be placed over each photodetector to sharpen the spectral response. Three such photodetectors can form a pixel of an active matrix array for an image sensor. The different photodetectors in each pixel can be multiplexed electronically. The electronic circuits for activating the different photodetectors can be integrated on the same substrate.

20200357945, Nov 12, 2020

May 9, 2019

16/407966

- Adelphi MD, US
Harry S. Hier - Sykesville MD, US
Ivan C. Lee - Excelsior MN, US
Mark Dubinskiy - Olney MD, US
Zun Zhang - Fairfax VA, US
Priyalal S. Wijewarnasuriya - Germantown MD, US

H01L 31/054
H01L 31/068

Method and system for wavelength thermophotovoltaic (WTPV) power generation. In one embodiment, the system comprises a refractory waveguide that collects broadband infrared light generated by a heat source; a filter that filters the collected broadband infrared light to generate narrow-band infrared light; and a thermophotovoltaic (TPV) converter, thermally de-coupled from the heat source, that receives the narrow-band infrared light and converts the received narrow-band infrared light to electrical power.