ABSTRACT
A unique ultranarrowband fiber-optic phase-shifted Fabry-Perot Bragg grating filter for atmospheric water vapor lidar measurements was designed, fabricated, and successfully tested. Customized optical fiber Bragg gratings were fabricated so that two transmission filter peaks occurred: one (89% transmission, 8 pm FWHM) near the 946-nm water vapor absorption line and the other peak (80% transmission, 4 pm FWHM) at a region of no absorption. Both transmission peaks were within a 2.66-nm stop band. Demonstration of tension tuning to the 946.0003-nm water vapor line was achieved, and the performance characterization of custom-made optical fiber Bragg grating filters are presented. These measurements are successfully compared to theoretical calculations using a piecewise-matrix form of the coupled-mode equations.
ABSTRACT
An all solid-state Ti:sapphire laser differential absorption lidar transmitter was developed. This all-solid-state laser provides a compact, robust, and highly reliable laser transmitter for potential application in differential absorption lidar measurements of atmospheric ozone. Two compact, high-energy-pulsed, and injection-seeded Ti:sapphire lasers operating at a pulse repetition frequency of 30 Hz and wavelengths of 867 and 900 nm, with M2 of 1.3, have been experimentally demonstrated and their properties compared with model results. The output pulse energy was 115 mJ at 867 nm and 105 mJ at 900 nm, with a slope efficiency of 40% and 32%, respectively. At these energies, the beam quality was good enough so that we were able to achieve 30 mJ of ultraviolet laser output at 289 and 300 nm after frequency tripling with two lithium triborate nonlinear crystals.
ABSTRACT
Two compact, high-pulse-energy, injection-seeded, 30-Hz frequency-doubled Nd:YAG-laser-pumped Ti: sapphire lasers were developed and operated at infrared wavelengths of 867 and 900 nm. Beams with laser pulse energy >30 mJ at ultraviolet wavelengths of 289 and 300 nm were generated through a tripling of the frequencies of these Ti:sapphire lasers. This work is directed at the replacement of dye lasers for use in an airborne ozone differential absorption lidar system. The ultraviolet pulse energy at 289 and 300 nm had 27% and 31% absolute optical energy conversion efficiencies from input pulse energies at 867 and 900 nm, respectively.
