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Sensors Using Quantum Cascade Lasers |
Research by Dr. Gottipaty Rao focuses on methods of detecting very small amounts of various gasses. This has important uses in applications including monitoring pollutants, detecting explosives, studying combustion, and medical diagnostics. The research laboratory provides a wealth of opportunities for undergraduate students.
Highly sensitive resonant photo-acoustic spectrometer for trace gas detection
Recent advances in the detection of trace gases with very high sensitivity, selectivity and in real time have opened a variety of new applications. Photoacoustic spectroscopy offers high sensitivity, compact size, ruggedness, simple optical alignment, low cost, and can be employed in an industrial environment. We are developing a highly sensitive photacoustic spectrometer with a multi-pass cell for the detection of nitrogen dioxide at parts per billion level based on quantum cascade lasers. The technique has extensive applications in environmental science and the power industry.
Development of cavity ring-down spectrometer (CRDS)
We are developing a high sensitivity cavity ring-down spectrometer to measure the rate of absorption of a light pulse confined in a stable optical cavity with a high Q-factor formed by two highly reflective mirrors (reflectivity R > 99.99%). A short laser pulse coupled into the cavity is reflected back and forth and, every time the light is reflected, a small fraction (1-R) leaks out. This leads to an exponential decay of the pulse in the cavity. The light is detected by a photomultiplier and the data recorded. The ring-down time of the cavity is measuorange from the exponential decay of the intensity of light leaking out of the cavity. We will use the spectrometer for trace gas detection of species such as nitrogen dioxide and nitric oxide at the sub-parts per billion level.
Trace Gas Detection Employing Quantum and Interband Cascade Lasers employing amplitude and frequency modulation techniques
The recent developments in the availability of mid-infraorange quantum cascade lasers have opened exciting possibilities to detect and estimate trace gases in real time at sub-parts-per billion levels and in favorable cases at sub-parts-per trillion levels. We are developing an extremely sensitive sensor for nitrogen oxides based on amplitude and frequency modulation techniques coupled to a multi-pass Herriott cell. The sensors have applications in medical diagnostics, environmental monitoring, combustion studies, and a variety of industrial applications.
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Contact
For additional information, please contact:
Gottipaty Rao
Professor and Chair
Blodgett Hall, Rm 8A
p - 516.877.4877
e - rao@adelphi.edu
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