Sensing of molecular hydrogen using direct tunable diode laser absorption spectroscopy.

This study presents sensitive and precise measurements of molecular hydrogen using direct tunable diode laser absorption spectroscopy (TDLAS). The S(1) H quadrupole transition at 2122 nm (4713 cm) was investigated using an 11.4-meter multipass cell.

Hydrogen Sensor Based on Tunable Diode Laser Absorption Spectroscopy.

A laser-based hydrogen (H) sensor using wavelength modulation spectroscopy (WMS) was developed for the contactless measurement of molecular hydrogen. The sensor uses a distributed feedback (DFB) laser to target the H quadrupole absorption line at 2121.8 nm.

New Opportunities in Mid-Infrared Emission Control.

Tunable laser absorption spectroscopy (TLAS) has been well accepted as a preferred measurement technique for many industrial applications in recent years, especially for in situ applications. Previously, mainly near-infrared lasers have been used in TLAS sensors. The advent of compact mid-infrared light sources, like quantum cascade lasers and interband cascade lasers, has made it possible to detect gases with better sensitivity by utilizing fundamental absorption bands and to measure species that do not have any absorption lines in the near-infrared spectral region.

High-energy single-longitudinal mode nearly diffraction-limited optical parametric source with 3 MHz frequency stability for CO2 DIAL.

We report on a 2.05 microm nanosecond master oscillator power amplifier optical parametric source for CO2 differential-absorption lidar. The master oscillator consists of an entangled-cavity nanosecond optical parametric oscillator based on a type II periodically poled lithium niobate crystal that provides highly stable single-longitudinal-mode radiation.