PROCEEDINGS ARTICLE | August 28, 2010
Proc. SPIE. 7808, Infrared Remote Sensing and Instrumentation XVIII
KEYWORDS: Infrared sensors, Carbon dioxide, Sensors, Spectroscopy, Remote sensing, Oxygen, Sensor networks, Laser spectroscopy, Absorption spectroscopy, Photoacoustic spectroscopy
We describe our novel instrumentation architectures for infrared laser spectrometers. Compact, power
efficient, low noise modules allow for optimized implementation of cell phone sized sensors using
VCSELs, diode, and quantum cascade laser sources. These sensors can consume as little as 0.3W with full
laser temperature (<0.001K/Hz1/2) and current control (<2ppm/Hz1/2 noise), photodiode preamplification
(<2pA/Hz1/2 noise floor, 1MΩ transimpedance), and digital lock-in amplification with 3 independent
channels. We have implemented sensors based on laser absorption spectroscopy, photoacoustic
spectroscopy, and Faraday rotation spectroscopy using the openPHOTONS systems, with performance
rivaling standalone laboratory measurement instrumentation. Additionally, as openPHOTONS is an open
source software repository, this instrumentation can be quickly adapted to new optical configurations
and applications. Such modules allow the development of flexible sensors, whether implementing
closed path spectrometers, open path perimeter monitoring, or remote backscatter based sensors. This
work is also the enabling technology for wireless sensor networks (WSN) of precision sensors, a
desirable sensing paradigm for long term, wide area, precision, temporally and spatially resolved
studies. This approach can complement existing remote sensing and mapping technologies including
satellite observations and sparse networks of flux towers.
