Effects of side subsurface defects induced by CNC machine on the gain spatial distribution in neodymium phosphate glass

Abstract

The processing method applied to the side surface is different from the method applied to the light pass surface in neodymium phosphate glass (Nd:glass), and thus subsurface defects remain after processing. The subsurface defects in the side surface influence the gain uniformity of Nd:glass, which is a key factor to evaluate the performance of amplifiers. The scattering characteristics of side subsurface defects were simulated by finite difference time domain (FDTD) Solutions software. The scattering powers of the glass fabricated by a computer numerical control (CNC) machine without cladding were tested at different incident angles. The trend of the curve was similar to the simulated result, while the smallest point was different with the complex true morphology. The simulation showed that the equivalent residual reflectivity of the cladding glass can be more than 0.1% when the number of defects in a single gridding is greater than 50.

Monolithic edge-cladding process for the elliptical disk of N31-type Nd-doped high-power laser glass

“…The residual reflectivity of the cladding interface depends mainly on the bubbles and the delaminations generated during the monolithic edge-cladding process by the optimized edge-cladding glass. If there are still subsurface defects, the equivalent residual reflectivity will be up to 10 -3 even if the effects between the defects are ignored [35] . As stated in Section 3.2, the defects can be removed by Step 1 in Figure 1, and so there is no delamination at the cladding interface.…”

Status and development of high-power laser facilities at the NLHPLP

“…This later inspired the actual technical improvements of the SG-II UP nanosecond facility; a high-power laser prototype was launched to further pursue the optimization of the laser design and additionally test the 1ω output potential with investigations of the final optical issues. With some parameters changed by optimization and technical upgrade [55][56][57][58][59][60][61][62][63][64] , the outputs of 16 kJ/5 ns/1ω and 17.5 kJ/20 ns/1ω were achieved based on 16 Nd:glass slabs (11 slabs in the cavity amplifier and 5 slabs in the power amplifier) with 40 mm thickness. More than 100 shots with different pulse widths and energies in the 1ω output were finished in 2016.…”

Optimizing the cleanliness in multi-segment disk amplifiers based on vector flow schemes

“…Due to the increase in laser energy and the expansions of the laser driver's scale, the cleanliness of the working environment with numerous optical elements has greatly affected the construction cycle and operating life of the high power solid-state laser driver [1][2][3][4] . Recent studies have shown that flashlamp illumination is a major factor causing damage to the lasing media (slab or disk) when the contaminant particles deposit onto the surface of the optical element in a multi-segment Nd:glass disk laser amplifier [5][6][7][8] .…”