Nuditha T Amarasinghe

US Patent:

7313158, Dec 25, 2007

Filed:

Feb 8, 2005

Appl. No.:

11/055128

Inventors:

Gary Alan Evans - Plano TX, US
Taha Masood - Plano TX, US
Steven Gregory Patterson - Plano TX, US
Nuditha Vibhavie Amarasinghe - Richardson TX, US
Jerome K. Butler - Richardson TX, US

Assignee:

Photodigm, Inc. - Richardson TX

International Classification:

H01S 5/00
H01S 3/13
H01S 3/08

US Classification:

372 50124, 372 29016, 372 29023, 372102

Abstract:

A single-mode grating-outcoupled surface emitting (GSE) semiconductor laser architecture is provided. This architecture enables high speed modulation of the GSE laser, which is accomplished by only varying the relative phase of counter propagating waves in the outcoupler grating region of the lasing cavity.

US Patent:

7313159, Dec 25, 2007

Filed:

Dec 23, 2004

Appl. No.:

11/021535

Inventors:

Nuditha Vibhavie Amarasinghe - Richardson TX, US
Taha Masood - Plano TX, US
Steven Gregory Patterson - Plano TX, US
Gary Alan Evans - Plano TX, US

Assignee:

Photodigm, Inc. - Richardson TX

International Classification:

H01S 3/08
H01S 5/00

US Classification:

372102, 372 501, 372 5011, 372 50124

Abstract:

An improved grating-outcoupled surface-emitting semiconductor laser architecture is provided. A second-order grating is placed between two distributed Bragg reflector gratings. The period of the second order grating is positively or negatively detuned from the distributed Bragg reflector selected optical wavelength at which the laser operates. Detuning of the second-order grating towards shorter or longer wavelengths allows kink-free, linear LI curves light output versus forward current) for grating-outcoupled surface-emitting lasers. Due to the detuning of the outcoupler grating, the outcoupled radiation emits two beams that deviate slightly from the normal axis. A design point may then be chosen where the power outcoupled by symmetric and antisymmetric modes cross and where the outcoupled power is independent of the phase variation.

US Patent:

8548022, Oct 1, 2013

Filed:

Apr 25, 2012

Appl. No.:

13/455860

Inventors:

Nuditha Vibhavie Amarasinghe - Richardson TX, US
Cheryl Achtenhagen - Plano TX, US

International Classification:

H01S 5/00

US Classification:

372 4501, 372 5011

Abstract:

The illustrated embodiments provide a system and a method of manufacture for a complex-coupled distributed feedback laser diode. The improved laser diode has a complex-coupled metal grating to enforce the laser to emit in a longitudinal single-frequency and suppress dynamical instabilities. In addition, the improved device uses a transparent conductive cladding layer over the metal grating and makes therefore the need for re-growth redundant.

US Patent:

20040141540, Jul 22, 2004

Filed:

Jan 22, 2003

Appl. No.:

10/348920

Inventors:

Taha Masood - Plano TX, US
Steven Patterson - Plano TX, US
Gary Evans - Plano TX, US
Nuditha Amarasinghe - Richardson TX, US

Assignee:

Photodigm, Inc. - Richardson TX

International Classification:

H01S005/18

US Classification:

372/097000

Abstract:

A laser diode system is provided. The laser comprises first and second reflective gratings at each end of the laser. The laser further comprises an outcoupling grating between the first and second reflective gratings, wherein the outcoupling grating couples light out of the laser. The reflectors and outcoupling grating each have a unique wide-band reflective spectrum. A first laser cavity exists between the first and second reflective gratings. A second laser cavity exists between the first reflective grating and the outcoupling grating. A third laser cavity exists between the second reflective grating and the outcoupling grating, and a fourth laser cavity exists with in the outcoupling region. The overlap of reflective spectra determine the lasing wavelengths that reach resonance within each cavity. Wavelengths resonant in one cavity are suppressed in the others unless a wavelength is resonant in all cavities. This matching of mode intensities causes the outcoupled beam to be confined to a single wavelength.

US Patent:

20080225918, Sep 18, 2008

Filed:

Mar 14, 2007

Appl. No.:

11/686082

Inventors:

Martin Achtenhagen - Plano TX, US
Gary Alan Evans - Plano TX, US
Nuditha Vibhavie Amarasinghe - Richardson TX, US
Taha Masood - Plano TX, US
Jerome K. Butler - Richardson TX, US

International Classification:

H01S 5/026

US Classification:

372 4401, 438 29

Abstract:

A system and a method of manufacture for a semiconductor laser with a continuous waveguide ridge extending the length of the laser. The continuous waveguide ridge is positioned through the center of the optical components of the semiconductor laser. The optical components including the waveguide ridge may be distributed Bragg reflectors (DBRs), outcoupling gratings, and phase controllers. The illustrated embodiments include lateral-grating grating-stabilized edge-emitting lasers and lateral-grating grating-stabilized surface-emitting (GSE) lasers. Both loss-coupled and non-loss-coupled lateral-grating components are illustrated.

US Patent:

20090168820, Jul 2, 2009

Filed:

Dec 28, 2007

Appl. No.:

11/966908

Inventors:

Martin Achtenhagen - Plano TX, US
Nuditha Vibhavie Amarasinghe - Richardson TX, US

International Classification:

H01S 3/042

US Classification:

372 34

Abstract:

A semiconductor laser system comprising a gain region, a gain contact coupled to the gain region, and a distributed Bragg reflector (DBR) having a near side and a far side with respect to the gain region are provided. The DBR reflects a resonant frequency of light back into the gain region. The semiconductor laser system further comprises a heat conducting structure, wherein the heat-conducting structure is positioned to transfer heat in a direction from the near side to the far side of the DBR grating, and an outcoupler, positioned to outcouple the resonant frequency of light from the semiconductor laser system.