Quantum Cascade Laser Spectrometer

Short Name or Variable Name

Note: Effective August 1, 2018, the Quantum Cascade Laser Spectrometer is no longer requestable through the NSF Lower Atmosphere Observing Facilities Deployment Pool.

  • There are two separate components to this instrument, both using quantum-cascade tunable infrared laser differential absorption spectroscopy. One module measures CO2 with an accuracy of 0.1 ppm and a time response of one second. The second measures CO, CH4, and N2O, also with the response time of one second. The two instruments share a single aircraft rack. The instrument uses an infrared tunable quantum cascade laser. Detection is via a compact long-path cell. Two lasers are configured to measure CO, CH4, and N2O, at 1 Hz frequency and with very high precision (better than 0.5, 1.0, and 0.1 ppb Hz-1/2, respectively). A second short-path cell of a new design provides high-precision CO2 measurements (better than 0.1 ppm Hz-1/2 ) using a third QC-laser.
    • (Top left)  Long-path, dual laser, CO_CH4_N2O sensor. Flight hardware with the long-path cell, dual laser assemblies, dual detectors (in one housing), etc., on the shock-mounted optical bench.
    • (Top right)  Assembly showing the purged pressure housing.
    • (Bottom)  CO2 HAIS sensor. Flight hardware of the optical module showing (1) dual detector, (2) dual 4 cm cells, (3) QCL laser assembly.


The QCLS in a GV rack as installed for flight.


Calibration Methods

in-flight calibration uses standards carried in gas cylinders

Primary External Contacts
Steve Wofsy, Harvard University
Lead Contact
Steve Wofsy, Harvard University