Richard Maulini

US Patent:

8014430, Sep 6, 2011

Filed:

Feb 27, 2009

Appl. No.:

12/395576

Inventors:

Alexei Tsekoun - Los Angeles CA, US
Richard Maulini - Los Angeles CA, US
Arkadiy Lyakh - Los Angeles CA, US
Laurent Diehl - Cambridge MA, US
Qijie Wang - Cambridge MA, US
Federico Capasso - Cambridge MA, US

Assignee:

President and Fellows of Harvard College - Cambridge MA

International Classification:

H01S 5/00

US Classification:

372 45012, 372 4401

Abstract:

A quantum cascade laser utilizing non-resonant extraction design having a multilayered semiconductor with a single type of carrier; at least two final levels ( and ) for a transition down from level ; an energy spacing Egreater than E; an energy spacing Eof about 100 meV; and an energy spacing Eabout equal to E. The carrier wave function for level overlaps with the carrier wave function for level. Likewise, the carrier wave function for level ′ overlaps with the carrier wave function for level. In a second version, the basic design also has an energy spacing Eof about 90 meV, and levels and ′ do not have to be spatially close to each other, provided that level has significant overlap with both these levels. In a third version, there are at least three final levels (, and ) for a transition down from level. Each of the levels , and has a non-uniform squared wave function distribution.

US Patent:

8068524, Nov 29, 2011

Filed:

Dec 28, 2010

Appl. No.:

12/980164

Inventors:

Arkadiy Lyakh - Marina del Ray CA, US
Alexei Tsekoun - Los Angeles CA, US
Richard Maulini - Los Angeles CA, US

Assignee:

Pranalytica, Inc. - Santa Monica CA

International Classification:

H01S 3/04

US Classification:

372 34, 372 36

Abstract:

A submount for a semiconductor laser. The submount has a layer of silicon carbide (SiC) and a layer of aluminum nitride (AlN) deposited on the layer of SiC. The submount is bonded to the InP-based laser by a hard solder applied to the AlN layer. Preferably, the thickness of the AlN layer is ten to twenty microns, the thickness of the SiC layer is two hundred fifty microns, and the solder is a gold-tin (AuSn) eutectic. The semiconductor laser may be a quantum cascade laser (QCL). Similar combinations of submount materials can be found for other semiconductor laser material systems and types.

US Patent:

8121164, Feb 21, 2012

Filed:

Dec 22, 2010

Appl. No.:

12/976856

Inventors:

Arkadiy Lyakh - Marina del Rey CA, US
Richard Maulini - Los Angeles CA, US
Alexei Tsekoun - Los Angeles CA, US

Assignee:

Pranalytica, Inc. - Santa Monica CA

International Classification:

H01S 5/00

US Classification:

372 4401, 372 4501

Abstract:

A quantum cascade laser (QCL) having a bias-neutral design and a semiconductor with multiple layers of AlInAs/InGaAs. The first active region barrier has a thickness of less than fourteen angstroms, and the second active region barrier has a thickness of less than eleven angstroms. The lower active region wavefunction overlaps with each of the injector level wavefunctions. Also, the laser transition is vertical at a bias close to roll-over. The injector level ′ is above a lower laser level , the injector level ′ is below the lower laser level , and the active region level is confined to the active region. The lower laser level is separated from the active region level by the energy of the LO phonon. The remaining active region states and the remaining injector states are either above the lower laser level or significantly below the active region level.

US Patent:

20080159341, Jul 3, 2008

Filed:

Jun 22, 2007

Appl. No.:

11/821528

Inventors:

Ilya Dunayevskiy - Los Angeles CA, US
Manu Prasanna - Marina del Rey CA, US
Rowel C. Go - Carson CA, US
Alexei Tsekoun - Los Angeles CA, US
Michael Pushkarsky - San Diego CA, US
Richard Maulini - Los Angeles CA, US

International Classification:

H01S 3/10
H01S 3/108
G01N 21/00
H01S 3/104

US Classification:

372 20, 372 23, 372102, 356437, 372 36

Abstract:

Methods and apparatus for broad tuning of single wavelength quantum cascade lasers and the use of light output from such lasers for highly sensitive detection of trace gases such as nitrogen dioxide, acetylene, and vapors of explosives such as trinitrotoluene (TNT) and triacetone triperoxide (TATP) and TATP's precursors including acetone and hydrogen peroxide. These methods and apparatus are also suitable for high sensitivity, high selectivity detection of other chemical compounds including chemical warfare agents and toxic industrial chemicals. A quantum cascade laser (QCL) system that better achieves single mode, continuous, mode-hop free tuning for use in L-PAS (laser photoacoustic spectroscopy) by independently coordinating gain chip current, diffraction grating angle and external cavity length is described. An all mechanical method that achieves similar performance is also described. Additionally, methods for improving the sensor performance by critical selection of wavelengths are presented.

US Patent:

20110102788, May 5, 2011

Filed:

Nov 1, 2010

Appl. No.:

12/917399

Inventors:

IIya Dunayevskiy - Los Angeles CA, US
Manu Prasanna - Marina del Rey CA, US
Rowel C. Go - Carson CA, US
Alexei Tsekoun - Los Angeles CA, US
Michael Pushkarsky - San Diego CA, US
Richard Maulini - Los Angeles CA, US

International Classification:

G01J 3/30
G01J 3/00

US Classification:

356318, 356300

Abstract:

Methods and apparatus for broad tuning of single wavelength quantum cascade lasers and the use of light output from such lasers for highly sensitive detection of trace gases such as nitrogen dioxide, acetylene, and vapors of explosives such as trinitrotoluene (TNT) and triacetone triperoxide (TATP) and TATP's precursors including acetone and hydrogen peroxide. These methods and apparatus are also suitable for high sensitivity, high selectivity detection of other chemical compounds including chemical warfare agents and toxic industrial chemicals. A quantum cascade laser (QCL) system that better achieves single mode, continuous, mode-hop free tuning for use in L-PAS (laser photoacoustic spectroscopy) by independently coordinating gain chip current, diffraction grating angle and external cavity length is described. An all mechanical method that achieves similar performance is also described. Additionally, methods for improving the sensor performance by critical selection of wavelengths are presented.

US Patent:

20110103411, May 5, 2011

Filed:

Nov 1, 2010

Appl. No.:

12/917383

Inventors:

Ilya Dunayevskiy - Los Angeles CA, US
Manu Prasanna - Marina del Rey CA, US
Rowel C. Go - Carson CA, US
Alexei Tsekoun - Los Angeles CA, US
Michael Pushkarsky - San Diego CA, US
Richard Maulini - Los Angeles CA, US

International Classification:

H01S 3/10
H01S 3/098
H01S 3/13

US Classification:

372 19, 372 29021, 372 20

Abstract:

Methods and apparatus for broad tuning of single wavelength quantum cascade lasers and the use of light output from such lasers for highly sensitive detection of trace gases such as nitrogen dioxide, acetylene, and vapors of explosives such as trinitrotoluene (TNT) and triacetone triperoxide (TATP) and TATP's precursors including acetone and hydrogen peroxide. These methods and apparatus are also suitable for high sensitivity, high selectivity detection of other chemical compounds including chemical warfare agents and toxic industrial chemicals. A quantum cascade laser (QCL) system that better achieves single mode, continuous, mode-hop free tuning for use in L-PAS (laser photoacoustic spectroscopy) by independently coordinating gain chip current, diffraction grating angle and external cavity length is described. An all mechanical method that achieves similar performance is also described. Additionally, methods for improving the sensor performance by critical selection of wavelengths are presented.

US Patent:

20110103412, May 5, 2011

Filed:

Nov 1, 2010

Appl. No.:

12/917406

Inventors:

Ilya Dunayevskiy - Los Angeles CA, US
Manu Prasanna - Manna del Ray CA, US
Rowel C. Go - Carson CA, US
Alexei Tsekoun - Los Angeles CA, US
Michael Pushkarsky - San Diego CA, US
Richard Maulini - Los Angeles CA, US

International Classification:

H01S 3/10

US Classification:

372 20

Abstract:

Methods and apparatus for broad tuning of single wavelength quantum cascade lasers and the use of light output from such lasers for highly sensitive detection of trace gases such as nitrogen dioxide, acetylene, and vapors of explosives such as trinitrotoluene (TNT) and triacetone triperoxide (TATP) and TATP's precursors including acetone and hydrogen peroxide. These methods and apparatus are also suitable for high sensitivity, high selectivity detection of other chemical compounds including chemical warfare agents and toxic industrial chemicals. A quantum cascade laser (QCL) system that better achieves single mode, continuous, mode-hop free tuning for use in L-PAS (laser photoacoustic spectroscopy) by independently coordinating gain chip current, diffraction grating angle and external cavity length is described. An all mechanical method that achieves similar performance is also described. Additionally, methods for improving the sensor performance by critical selection of wavelengths are presented.

US Patent:

20110103416, May 5, 2011

Filed:

Nov 1, 2010

Appl. No.:

12/917376

Inventors:

Ilya Dunayevskiy - Los Angeles CA, US
Manu Prasanna - Marina del Rey CA, US
Rowel C. Go - Carson CA, US
Alexei Tsekoun - Los Angeles CA, US
Michael Pushkarsky - San Diego CA, US
Richard Maulini - Los Angeles CA, US

International Classification:

H01S 3/04

US Classification:

372 36, 372 4501

Abstract:

Methods and apparatus for broad tuning of single wavelength quantum cascade lasers and the use of light output from such lasers for highly sensitive detection of trace gases such as nitrogen dioxide, acetylene, and vapors of explosives such as trinitrotoluene (TNT) and triacetone triperoxide (TATP) and TATP's precursors including acetone and hydrogen peroxide. These methods and apparatus are also suitable for high sensitivity, high selectivity detection of other chemical compounds including chemical warfare agents and toxic industrial chemicals. A quantum cascade laser (QCL) system that better achieves single mode, continuous, mode-hop free tuning for use in L-PAS (laser photoacoustic spectroscopy) by independently coordinating gain chip current, diffraction grating angle and external cavity length is described. An all mechanical method that achieves similar performance is also described. Additionally, methods for improving the sensor performance by critical selection of wavelengths are presented.