Fatima Matroodi, Ali Ahmadi, Morteza Zargar Shoushtari, Humberto Cabrera,
Volume 16, Issue 1 (1-2022)
Abstract
Ti-doped tungsten disulfide (WS2) nanosheet-semiconductor is studied for thermo- optical and electronic properties. Thermal diffusivity (D) thermal conductivity (κ) and absorbance were determined as a function of Ti- dopant (0, 7, 14, and 28%). The research focused on the effect of different Ti-dopant concentrations, and we tried to evaluate the thermal parameters using photohermal lens technique as a simple, non-contacting method. The results show an increase in the values of D by 5 times with an increment of Ti-dopant from 0% to 28%. The addition of Ti did not produce any additional phase in the material, although, the separation of the crystallographic planes reduced, indicating the presence of the Ti atoms in the crystal structure.
Saeid Radmard, Ahmad Moshaii, Mohammad Abazari,
Volume 16, Issue 1 (1-2022)
Abstract
This paper presents the design procedure of folded-resonators for high-average power thin-disk lasers (TDLs). Because of the oblique angle of incidence in the laser path inside the resonator, folded resonators introduce astigmatism. Additionally, the dependency of the dioptric power of the active medium on the pump power made the resonator design more complicated. In the first section of this work, the disk thermal lensing was measured using a wavefront sensor, and the measurement procedure was presented and thoroughly discussed. The disk radius of curvature varied between 4.3 m to 6.4 m depending on the pump power. The disk was considered a variable lens inside the resonator based on the measurement results. V-shaped and L-shaped configurations' stability and M2 factor were predicted, optimized, and compared. Astigmatism in the resonator parameters was considered and discussed. While the V-shaped cavity has better beam quality, the L-shaped cavity has less sensitivity to cavity misalignment. The primary approach of this paper was the resonator design of a cavity-dumped disk laser. However, the designed resonator configurations could be utilized in many laser resonators, such as industrial TDLs (to reduce the overall length of the system) and second harmonic-generation in TDLs.
