We propose to demonstrate an eye-safe laser source for a DIAL CO2 sensor that meets or exceeds all topic requirements for a high-pulse-energy laser with good beam quality, transform-limited spectrum, and efficiency >25%. Our approach will use a cavity-dumped resonator to directly generate Nd 1.4-micron pulsed output, and injection seeding for spectral narrowing. This approach, while based on established technology, is innovative in finding an optimal solution from uncommon elements. Our design allows us to start with a well-behaved four-level laser instead of the problematic quasi-three-level lasers like Er:YAG and Er:glass (fiber). Moreover, it avoids the loss in efficiency that comes from using an OPO pumped by the common 1-micron Nd or Yb laser to generate eye-safe near-IR output. We also propose to demonstrate that our laser performance is tolerant of high-temperature operation, making passive cooling possible with major advantages in overall size, weight, wall plug efficiency, and power scalability.
