Title:
OPTICAL WAVELENGTH METER
Document Type and Number:
WIPO Patent Application WO2004085980
Kind Code:
B1
Abstract:
An optical wavelength meter for measuring wavelength of an optical beam includes two periodic out of phase fine optical filters (44, 45), using, for example Fabry Perot etalon filters, Fizeau filters, fibre Bragg gratings or photonic crystals. The phases of the periodic responses are arranged such that a peak (5109 or trough (511) of one response coincides with a slope (522) of the other response so that a slope portion of a response may always be chosen for measurement. A coarse filter (43) is provided to unambiguously define on which cycle of the periodic response of the fine filters a measured wavelength lies. Synchronized clock signals are provided to measure output of the filters using, for example, photodiodes (421, 422, 423, 424), at a rate of (1,000 to 10,000) wavelength measurements per second.
More Like This:
Inventors:
O'GORMAN NEAL (IE)
O'DOWD RONAN (IE)
O'DOWD RONAN (IE)
Application Number:
PCT/EP2004/003010
Publication Date:
November 25, 2004
Filing Date:
March 22, 2004
Export Citation:
Assignee:
TSUNAMI PHOTONICS LTD (IE)
O'GORMAN NEAL (IE)
O'DOWD RONAN (IE)
O'GORMAN NEAL (IE)
O'DOWD RONAN (IE)
International Classes:
G01J9/02; (IPC1-7): G01J9/02
Download PDF:
Previous Patent: MEHTOD AND DEVICE FOR OPTO-ACOUSTICAL IMAGERY
Next Patent: THERMOWELL AND A METHOD OF MEASURING THE TEMPERATURE OF A PIPE
Next Patent: THERMOWELL AND A METHOD OF MEASURING THE TEMPERATURE OF A PIPE