Ling H Liu

US Patent:

52873773, Feb 15, 1994

Filed:

May 6, 1993

Appl. No.:

8/058997

Inventors:

Tadashi Fukuzawa - Tokyo, JP
Ling Y. Liu - White Plains NY
Emilio E. Mendez - Croton-on-Hudson NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01S 319

US Classification:

372 45

Abstract:

The present invention is the use of coupled quantum wells in the active region of a semiconductor laser to modulate the frequency and amplitude of the light output of the laser. In a particular embodiment of the present invention the coupled quantum wells are contained in a graded index of refraction semiconductor double heterostructure laser. The active region of this tunable laser consists of two quantum wells having a width of approximately 50 Angstroms or less which are separated by a barrier layer having a width of approximately 20 Angstroms or less. The quantum well material is intrinsic GaAs and the barrier layer is Al. sub. x Ga. sub. 1-x As wherein x=0. 23. The active region is surrounded by the double heterostructure in which one side is doped p-type and the second side is doped n-type. The resulting laser is a p-i-n type structure. A reverse bias with respect to the flat band voltage of the p-i-n structure is applied across the p-i-n structure which modulates both the frequency and the intensity of the laser output.

US Patent:

20200025706, Jan 23, 2020

Filed:

Aug 31, 2016

Appl. No.:

16/329254

Inventors:

- Morris Plaiins NJ, US
Ling LIU - Morris Plains NJ, US
Feng LIANG - Morris Plains NJ, US

International Classification:

G01N 27/30
G01N 27/38
G01N 27/403

Abstract:

Methods and systems for identifying contamination of an electrochemical sensor () and cleaning the electrochemical sensor () are provided. A method may comprise scanning the sensor () for the first time using CV to generate a reference set of readings; scanning the sensor () for the second time after the sensor () has been employed; comparing a second set of readings from the second CV scan to the reference set of readings; when the second set of readings is different from the reference set of readings, determining that the sensor () potential has shifted; scanning the sensor () for the third time to clean one or more elements of the sensor (); scanning the sensor () for the fourth time; comparing a fourth set of readings from the fourth CV scan to the second set of readings; and determining that the potential of the sensor () has shifted due to pollution of the sensor (), and/or that the sensor () can be further cleaned.

US Patent:

20190317043, Oct 17, 2019

Filed:

Jul 12, 2016

Appl. No.:

16/317097

Inventors:

- Morris Plains NJ, US
Yuzhong YU - Morris Plains NJ, US
Ling LIU - Morris Plains NJ, US

Assignee:

Honeywell International Inc. - Morris Plains NJ

International Classification:

G01N 27/407
G01N 27/30

Abstract:

An electrochemical hydrogen cyanide sensor () comprises a housing () comprising an opening () allowing gas to enter the sensor (); an electrolyte disposed within the housing (); a plurality of electrodes in contact with the electrolyte within the housing (), wherein the plurality of electrodes comprise a working electrode () and a counter electrode (), and wherein the electrodes comprise a metal catalytic material; and a filter () operable to cover the opening () of the housing (), and prevent hydrogen sulfide from reaching the electrodes, wherein the filter () comprises silver sulfate layered onto a polytetrafluoroethylene support material.