Description:
The primary objective is to develop a narrow-band, tunable, diode-pumped solid-state (DPSS) pulsed laser system operating in the eye-safe infrared region around 1.6 micrometers in wavelength. Such laser systems are in demand for remote sensing of fugitive emissions, which can cost millions of dollars to industry, as well as for sensing and mitigation of pollutants for regulatory requirements and research. These applications demand high repetition rates (1 kHz – 10 kHz) and high-energy (>1 mJ) pulses.
Currently available commercial technologies for generating laser light in this region include telecommunications lasers using erbium-doped fibers, and optical parametric oscillators pumped by two additional laser systems. The former are limited in pulsed power output by nonlinear processes within the fiber, and the latter are complex and limit the field-portability of remote sensing instruments. The development of a system with orders of magnitude higher pulse energy than telecommunications lasers and lower complexity than optical parametric oscillator-based systems is necessary to advance these limitations.
Diode-pumped solid-state lasers using erbium ions embedded in a crystal matrix (such as YAG or YVO4), which have emission lines in the appropriate spectral region, have been developed and demonstrated to be suitable for both high-energy and high-repetition rate pulse production[1-6]. The grantee will develop and commercialize a system, or set of systems, optimized for remote sensing applications.
The project outcome should be a turnkey, environmentally robust DPSS Er-ion based laser system with high mode quality, high pulse energy, and high repetition frequency. The pulse duration should be in the tens of nanoseconds and the linewidth should be as close to transform limited as is practical. A state-of-the-art optical parametric oscillator based system can generate pulses of several tens of mJ at a 100 Hz repetition rate when pumped with a high-power Nd:YAG [7]. The project outcome should have comparable pulse energies and have a variable repetition rate exceeding 1 kHz and not exceeding 20 kHz. The laser should be capable of being reconfigured for a variety of spectroscopic lines and targets (for example, the 1570 nm CO2absorption range as well as the 1645 nm CH4range). There should also be fine tunability of the laser to densely sample points across a typical absorption feature. This tuning could be achieved, for example, by seeding with a tunable diode laser.
Phase I activities and expected results:
1) Design of laser platform including material selection
2) Performance modeling of laser platform
3) Feasibility study of use of laser design for detection of CH4and CO2.
Phase II activities and expected results:
1) Construction of laser system
2) Performance characterization of laser system
3) Environmental testing of laser system
4) Demonstration of absorption spectroscopy on at least one spectroscopic target using the laser
On a case-by-case basis, NIST may provide technical experts to work with Phase I and Phase II awardees and may consult and provide input through discussions.
