Segment side-pumped Q-switched Nd:YAG laser

Abstract

In the design of conduction-cooled lasers, a side-pumped configuration is an attempt to solve the space conflict between pump and heat removal. The pump radiation always competes with the heat removal and mechanical support device for the lateral surface of a laser rod. This space conflict can be addressed by a segment side-pumped configuration in which circular laser diode arrays and heat-conducting rod holders alternate periodically along the length of the laser rod. This scheme permitted 11 Hz operation of a 190 mJ Q-switched laser at the wavelength of 1064 nm without the use of liquid cooling for both the laser rod and laser diode arrays and the corresponding optical-optical conversion efficiency of 23.1%. Thus, it has great potential to be used in compact and miniature laser systems.

A seven-parameter BRDF model for retro-reflection

“…Based on experimental data measured by the in-plane BRDF measurement setup, the comparative results of the BRDF calculated by the five-parameter BRDF model (shown as curves) optimized by the hybrid artificial bee colony algorithm [20] and measured by the BRDF measurement setup (shown as discrete points) of three kinds of samples (sample #1, aluminum plate with coating of brown paint; sample #2, aluminum plate with coating of light green paint, sample #3, aluminum plate with coating of bottle green paint) are shown in figure 1. The incident angles are 0,25,35.…”

“…The BRDF experimental data has a small retro-reflection peak due to backreflected when the incident angle equals the scattering angle. To assess the performance of the seven-parameter BRDF model, the hybrid artificial bee colony algorithm [20] was used to fit the undetermined parameters in the five-parameter and the seven-parameter BRDF model based on the experimental data. We chose the least-mean-square error (LMSE) between the experimental and the calculated data calculated by the two different BRDF models as an objective function.…”

Optical Interferometric MEMS Accelerometers

“…[ 107 ] In the above scheme, although a large amount of wavelength change can be realized through temperature, its timeliness is poor due to the hysteresis of temperature transfer. Based on this, Qiaoyun Wang [ 97 ] et al. combined a laser and a tuned Fabry‐Perot filter to form a tuned fiber laser ( Figure a).…”

Thermo-Optic Numerical Research on Segmented Circular LD Arrays Side-Pumping a Nd:YAG Laser Rod

“…Finally, the heat is removed by the segmented holders. This scheme reduces the thermal lensing caused by the radial temperature gradient and has been demonstrated in applications of Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) [10] and Raman [11,12] lasers. However, no detailed comparative research has yet been conducted on the temperature distributions and thermo-optic effects in laser rods between this scheme and the other side-pumping schemes under the same cooling boundary conditions.…”