T. Fujioka

High-efficiency operation of chemical oxygen-iodine laser using nitrogen as buffer gas

High-efficiency operation of supersonic chemical oxygen-iodine laser (COIL) with an advanced jet-type singlet oxygen generator using nitrogen as buffer gas was demonstrated. Laser output was remarkably increased when buffer gas was cooled with liquid nitrogen. The effects of buffer gas temperature on the characteristics of the oxygen-iodine laser medium was discussed. A net chemical efficiency of 23.4% was obtained at 405 W when the chlorine molar flow rate was 19 mmol/s.

Trace NO/sub 2/ detection with Yb fiber laser pumped mid-IR difference frequency generation

A novel high power Yb fiber laser pumped cw narrow-linewidth tunable mid-IR coherent source based on a difference frequency generation (DFG) in a periodically poled LiNbO/sub 3/ (PPLN) crystal for trace gas detection was demonstrated.

An experimental study on a cylindrical multi-pass cell

A new type multi-pass cell was demonstrated for absorption spectroscopy. This cell is useful when performing gas measurement. Moreover, the optical characteristic of a cell was verified.

Instantaneous measurement of NH/sub 3/ and NO/sub x/ by using near- and mid-infrared coherent light sources

Instantaneous measurement of NH/sub 3/ and NO/sub x/ both in near-infrared (near-IR) and mid-infrared (mid-IR) region provided by single difference frequency generation device is demonstrated.

An intelligent gas detector based on Raman scattering spectroscopy pumped by power build-up cavity

Intelligent gas detection to monitor Hydrogen concentration based on stokes Raman scattering was demonstrated. Power Build-up Cavity (PBC) as a light source, Avalanche Photo Diode (APD) was employed. The detection limit was lower than 200ppm.

Dual gas (NH 3 and NO 2 ) laser absorption measurement by tailored signal and idler wavelength in difference frequency mixing process

Absorption measurements of NH3in 1.53 μm wavelength region and NOx in 3.46 μm wavelength region are performed at the same instant by using single optical gas sensing system based on difference frequency generation (DFG).

An ultra-compact NO2 detector based on cavity ringdown spectroscopy using a laser diode pumped power build-up cavity

A novel gas detector to monitor nitrogen dioxide (NO2) concentration based on continuous-wave cavity ringdown spectroscopy was demonstrated. A sensitivity of 2 × 10^-7cm^-1was achieved using a compact laser diode power build-up cavity.

A characteristic analysis of laser resonators

Some resonators were two-dimensionally analyzed zed using a partially coherent input field. The calculation based on the Fresnel-Kirchhoff integral formula showed the applicability of new type resonators to high-power and high-quality laser.

Measurement of transient absorption change of NO/sub 2/ at 3.46 /spl mu/m using difference frequency generation

Rapid NO/sub 2/ detection by mid-infrared coherent light source based on difference frequency generation that used a fiber laser as pumping source was demonstrated. High resolution spectroscopic measurements of NO/sub 2/ are reported.

NH/sub 3/ detection under water vapor influence by mid-IR source based on Yb fiber laser pumped difference frequency generation

NH/sub 3/ detection in water vapor contained gas mixture with mid-IR light source at 3 /spl mu/m based on difference frequency generation was demonstrated. High spectral resolution measurements of NH/sub 3/ avoiding interference of water are reported.