Search

This work investigates a tunable laser absorption spectroscopy technique for the H 2 O concentration by a Tm:YAP solid-state laser. The output wavelength of Tm:YAP laser is tuned by a birefringence filter and an F-P etalon in the laser cavity. The tuning range is from 1910 nm to 1914 nm, the tuning frequency is 1 Hz. With the tunable Tm:YAP laser, we realize a concentration resolution of 10 ppb. Different concentrations of H 2 O vapor are use to test the precision of the system. A maximum relative error of 0.8% is realized. At the same time, we calculate the maximum absolute error to be 0.8 ppm. Up to the authors’ knowledge, it is the first time to report a tunable laser absorption spectroscopy for the gas concentration measurement by a Tm-doped laser. [ABSTRACT FROM AUTHOR]

This work investigates the feasibility of TDLAS technique in the NO concentration measurement for the marine diesel engine. A system in laboratory is devised for the NO steady state measurement. An ICL laser whose center wavelength is 5263 nm is chosen for the detection. With the direct detection method, a resolution about 2 ppm is realized, and the relative error is less than 5%. In contrast to the direct detection method, the harmonic detection method realizes a higher resolution, and the error is better less 3%. Considering with the temperature fluctuation of the diesel emission, the absorption line strength is calculated from 300 K to 500 K. At the same time, the intensity of the 2f signal is measured, which is proportional to the change of the line strength. So a modification can be imported easily to avoid the error produced by the temperature fluctuation. The TDLAS proposed in this work can realize a high precision, high resolution, and transient measurement for the marine diesel emission. [ABSTRACT FROM AUTHOR]

Represented here is an electron-optic Q switch Ho:ScSi 2 O 5 laser. A RTP crystal was employed as the Q-switch element. It is the first time to demonstrate an electron-optic Q switch Ho:ScSi 2 O 5 laser, whose maximum single-pulse energy reaches around 102 mJ, corresponding to a maximum peak power of 2.91 MW. The laser performance is investigated as a function of the different repetition frequencies and incident pump power. We focus on the low frequencies (1, 2, 5, 8, 10, and 20 Hz) in this contribution, aiming to obtain a higher single-pulse energy. The beam quality M 2 factor of the electron-optic Q switch Ho:ScSi 2 O 5 laser is measured by knife-edge method, which is calculated to be 1.24. [ABSTRACT FROM AUTHOR]