Yin Tao Wang

US Patent:

20120268743, Oct 25, 2012

Filed:

Nov 23, 2011

Appl. No.:

13/303648

Inventors:

Yin Wang - Princeton NJ, US
Gerard P. Wysocki - Princeton NJ, US
Feng Xie - Painted Post NY, US

International Classification:

G01N 21/25
F21V 13/12
F21V 13/10

US Classification:

356417, 362233

Abstract:

A system and process for automatically characterizing a plurality of external cavity semiconductor laser chips on a semiconductor laser bar separated from a semiconductor wafer. The system includes a diffraction grating and a steering mirror mounted on a rotary stage for rotating the diffraction grating through a range of diffraction angles. A laser bar positioning stage for automatically aligning each laser chip in a laser bar with the diffraction grating. Reflecting a laser beam emitted from a laser chip in a laser bar with diffraction grating and steering mirror to the laser analyzer. Automatically rotating the diffraction grating through a range of diffraction angles relative to the laser beam and automatically characterizing the laser optical properties such as spectra, power, or spatial modes with the laser analyzer at each diffraction angle.

US Patent:

20140268148, Sep 18, 2014

Filed:

Mar 17, 2014

Appl. No.:

14/215739

Inventors:

Yin Wang - Princeton NJ, US
Gerard Wysocki - Princeton NJ, US

Assignee:

THE TRUSTEES OF PRINCETON UNIVERSITY - Princeton NJ

International Classification:

G01J 4/04
G01N 21/21

US Classification:

356364

Abstract:

A dual-modulation Faraday rotation spectroscopic (FRS) system is disclosed. The FRS system uses an FRS sample cell configured to subject a sample to a low frequency modulated magnetic field. The system includes a polarized laser light source configured to generate a high frequency wavelength-modulated light beam incident on the sample, the high frequency wavelength-modulated light beam being modulated at a higher frequency than the low frequency modulated magnetic field. A polarizer is configured to receive from the sample a transmitted light beam having a modulated polarization having a polarization rotation and translate the modulated polarization of the transmitted light beam into an intensity modulated beam. A photodetector is configured to detect the intensity modulated beam and generate a photodetector signal. A dual demodulator is coupled to the photodetector and is configured to demodulate the photodetector signal.