Gas imaging with wavelength modulation spectroscopy and a micromirror array

Chris Hovde; Shin-Juh Chen; Kristen A. Peterson; Mark Paige

doi:10.1117/12.630770

4 November 2005 Gas imaging with wavelength modulation spectroscopy and a micromirror array

Chris Hovde, Shin-Juh Chen, Kristen A. Peterson, Mark Paige

Proceedings Volume 5995, Chemical and Biological Standoff Detection III; 59950I (2005) https://doi.org/10.1117/12.630770
Event: Optics East 2005, 2005, Boston, MA, United States

Abstract

Backscatter gas imaging uses laser absorption spectroscopy to detect the presence of a gas by illuminating a region with light from an infrared laser and imaging the returned light. Contrast can be enhanced by comparing the back-scattered intensity on and off the absorption feature. Wavelength modulation spectroscopy can provide just such a capability, but the detector signal must be processed with a lock-in amplifier, which is incompatible or prohibitively expensive with most array detectors. Images can be recorded using a single photodiode by spatially modulating the laser or the detected image. This paper describes initial experiments to demonstrate the feasibility of a combined wavelength- and spatially- modulated gas imager. It is based on a single near-infrared laser, a single detector, lock-in detection, and a commercial micromirror array. The gases imaged include water vapor, mono-deuterated water vapor, acetylene and hydrogen cyanide. Doppler imaging is demonstrated using heterodyne detection and spatial image modulation.

Citation Download Citation

Chris Hovde, Shin-Juh Chen, Kristen A. Peterson, and Mark Paige "Gas imaging with wavelength modulation spectroscopy and a micromirror array", Proc. SPIE 5995, Chemical and Biological Standoff Detection III, 59950I (4 November 2005); https://doi.org/10.1117/12.630770

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available