Solid state deep UV laser for Raman detection of CB agents

Raman spectroscopy is a highly effective non-contact laser remote sensing method for detecting and identifying chemicals in every-day field environments. Raman spectroscopy is particularly suited for detecting trace surface contaminants that may indicate the presence of explosives, harmful chemical or biological agents. Contemporary systems, such as the vehicle mounted Joint Contaminated Surface Detector (JCSD), use gaseous KrF excimer lasers operating at 248 nm as the pump laser source. One of the key objections to the KrF laser is the unique maintenance requirements for on-site gas refilling operations that complicate logistics and severely limit that systems reliability. In this SBIR program Arete Associates will develop an efficient, compact, light-weight and rugged diode-pumped solid-state laser alternative. The laser source will be based on a frequency quadrupled Q-switched single-frequency Nd ceramic YAG laser operating on the 946 nm transition to achieve the desired 236 nm output. This method is capable of meeting the desired operating specifications of<30 pm linewidth,>10 mJ pulse energy, 75 Hz pulse repetition rate,>100 ns pulsewidth,<25 lbs,<1800 cu. in and>10,000 hrs operational lifetime. Arete will utilize proprietary single-frequency, injection-seeded, self-aligning, image rotating resonator designs; advanced ceramic YAG materials with custom doping profiles; and efficient cascaded frequency doubling in borate crystals to achieve the desired deep UV output wavelength of 236 nm.