A new tool that has the ability to protect our borders has been recently developed by Northwestern University's Manijeh Razeghi.
Manijeh Razeghi (Credit: Northwestern's McCormick School of Engineering)
A new broad-band tunable infrared laser has been developed in Razeghi's lab, with the support from the Department of Homeland Security. It is a single-chip, all solid-state laser, and offers high-power rapid tuning. This new border protection laser can support drug and explosive detection.
It is possible to rapidly tune these powerful lasers for emitting in the wavelength range that covers the critical "fingerprint" wavelength region where absorption and identification of most molecular features take place by infrared sensing. In experimental demonstrations, the unique spectral fingerprints of gases have been successfully captured by the laser system.
The only moving part in the entire system is the fan used to keep the laser cool. This is a major advantage over existing systems that require mechanical parts to achieve tuning, and we expect to demonstrate remarkable stability.
Manijeh Razeghi, Walter P. Murphy Professor of Electrical Engineering and Computer Science in Northwestern's McCormick School of Engineering
The preliminary, patent-pending results have been presented in the June 8 publication of Scientific Reports. The successful development of the laser is the result of nearly two decades of development work in quantum cascade lasers at Northwestern University's Center for Quantum Devices.
The laser is coupled to a system that comprises of all the tuning software and laser driver electronics that are required for integrating the laser system into a spectroscopy system. A single-aperture spot that is less than 3mm in diameter is produced by the laser. This spot is stable and can be used for standoff detection. With stabilization time of less than 1ms/wavelength, it can also be used for random or linear access scanning.
The Department of Homeland Security Science and Technology Directorate, National Science Foundation, Naval Air Systems Command, DARPA, and NASA supported this research work.