Paul J. Schroeder

Dual Frequency Comb Spectroscopy of High Temperature Water Vapor: Absorption Model Development for Combustion Sensors

Absorption linestrength and lineshape parameters are extracted from measurements of pure water absorption between 6800 and 7200cm-1 from room temperature to 1300K using a dual frequency comb spectrometer with point spacing of 0.0033cm-1.

MULTISPECTRAL FITTING VALIDATION OF THE SPEED DEPENDENT VOIGT PROFILE AT UP TO 1300K IN WATER VAPOR WITH A DUAL FREQUENCY COMB SPECTROMETER

PAUL JAMES SCHROEDER, Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA; MATTHEW J. CICH, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA; JINYU YANG, Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA; BRIAN DROUIN, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA; GREG B RIEKER, Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA.

Dual-Comb spectroscopy for GHG quantification

Near-infrared frequency-comb spectroscopy is a powerful tool with which to measure concentrations of gasses relevant to combustion and atmospheric monitoring (CO2, CH4, H2O, HDO) over meter and kilometer scale paths.

Combustion Diagnostics and Chemical Sensing with Frequency Comb Lasers

Recent advancements in robust frequency comb laser design have enabled the first industrial implementations of dual-comb gas sensors. As an example, we demonstrate dual-comb spectroscopy in the exhaust of a 16 MW stationary gas turbine.

Large amplitude wavelength modulation spectroscopy for sensitive measurements of broad absorbers

We demonstrate wavelength modulation spectroscopy of CO 2 at >30 atm using a fast-scanning MEMS laser. The technique shows promise for sensitive measurements of species with broadband absorption features, such as high-pressure gases and large molecules.

Precision Atmospheric Trace Gas Monitoring with Frequency Comb Lasers

Accurate monitoring of trace gases requires high sensitivity, drift-free instruments. Dual frequency comb spectroscopy is a promising technique for kilometer-scale open-path monitoring of trace gases, owing to its low systematic uncertainty, high stability, and absorption-model-based calibration.

Micro Cryogenic Coolers With Mixed Refrigerants

A number of small electronic devices benefit from micro-scale low temperature operation. Recently we have developed micro cryogenic coolers (MCCs) using a low-pressure, mixed-refrigerant Joule-Thomson cycle. The cryocoolers utilizes a MEMS-enabled gas compressor coupled to a micro cold stage. Two cold stages have been developed: one which uses a fiber-enabled heat exchanger assembled to a micro-machined throttling valve, and another which uses a MEMS-based heat exchanger. A microcompressor has been developed which uses MEMS-based check valves coupled to a membrane, which is actuated with a mechanically amplified piezoelectric amplifier. The compressor measures a volume 15 mL, can generate a pressure ratio of 6:1 and a maximum flow-rate of 60 standard mL/min. The complete cryocooler has reached low temperatures of 177 K, although temperature instability has been an issue, due to 2-phase flow through the micro-channels. This paper will cover the development and testing of the micro cryogenic cooler, as well as an analysis of the micro channel flow. A proper understanding of the micro-channel flow allows us to design refrigerant mixtures to improve the cooling power, and modify the cooler to eliminate temperature instabilities.Copyright