Title :
MEMS scanning mirror used as an laser external modulator for photoacoustic spectroscopy
Author :
Li, Li ; Thursby, Graham ; Stewart, George ; Uttamchandani, Deepak
Author_Institution :
Univ. of Strathclyde, Glasgow, UK
Abstract :
We present a novel MEMS application aimed at laser based gas sensing. A low-cost MEMS based external intensity modulator for a laser diode source has been realised and applied to photoacoustic spectroscopy. By using a MEMS based modulator, pure intensity modulation of the laser emission is achieved without the accompanying wavelength modulation which occurs with diode current modulation. This reduces measurement error. We describe the use of the optical MEMS modulator/photoacoustic technique to recover the profile of the 1535.4nm absorption line of acetylene at 100pm concentration in the photoacoustic cell. Based on initial results, we predict a sensitivity of ~1ppm with this system.
Keywords :
gas sensors; intensity modulation; measurement by laser beam; micro-optomechanical devices; micromirrors; optical modulation; optical scanners; optical sensors; photoacoustic spectroscopy; semiconductor lasers; MEMS scanning mirror; gas sensing; intensity modulation; intensity modulator; laser diode; laser external modulator; measurement error; photoacoustic spectroscopy; Gas lasers; Micromechanical devices; Mirrors; Optical fibers; Optical modulation; Optical sensors;
Conference_Titel :
Optical MEMS and Nanophotonics (OPT MEMS), 2010 International Conference on
Conference_Location :
Sapporo
Print_ISBN :
978-1-4244-8926-8
Electronic_ISBN :
978-1-4244-8925-1
DOI :
10.1109/OMEMS.2010.5672157
