Multiple Remote Transmitter-Receiver Terahertz Spectroscopy System for Combustion Monitoring & High Speed Imaging

We propose to develop and construct a terahertz imaging and spectroscopy system capable of utilizing up to eight pairs of remote fiber coupled transmitters and receivers with simultaneous data acquisition. This system will enable the construction and testing of a linear array capable of high speed THz imaging. Additionally, this system will be configurable for simultaneous rapid spectroscopic measurements in multiple remote locations. The fiber optic coupled design allows the remote terahertz modules to be placed near harsh environments, such as combustion chambers, to measure thermal or species spatial profiles. In addition to demonstrating an increase an imaging speed, we propose to utilize the deliverable system at WPAFB to develop spectroscopic monitoring applications, such as determining temperature in combustion environments, through the measurement of the Boltzmann distribution of water vapor lines from 0.5 to 3 THz. A successful completion of tasks in year two will lead to a measurement in the 20-atm test rig in the High-Pressure Combustor Research Facility (HPCRF). The architecture of the system will allow the same terahertz modules to be employed in wideband time domain measurements (powered by a femtosecond laser) or in narrowband frequency domain measurements (powered by a optical heterodyne laser source).