Tomotaka Katsura

Improvement in UV Optical Properties of CsLiB6O10 by Reducing Water Molecules in the Crystal

We investigated the effects of water molecules in CsLiB6O10 (CLBO) crystals on UV optical properties. Our results show that long-term heat treatment is necessary to adequately remove water molecules from inside the crystal. The reducing the number of water molecules contained in the crystal improves the transmittance at 266 nm. In addition, the long-term heat-treated crystal can generate three-times higher 266-nm output without bulk damage than a normal sample.

Micro processing in glass substrates with pulsed CO 2 lasers

While glass is a good candidate material for interposer application, technology for formation of Through-Glass-Vias (TGVs) at high throughput and low cost is required. In this paper, we introduce micro processing technology with high-peak-power pulsed CO2 lasers which realizes high throughput at low initial and operating cost. Since the wavelength of the CO2 lasers is 9.3 microns, it is said to be difficult to drill holes with the diameters smaller than 40 microns. With a surface treatment technique of the substrate and fine tuning of the laser conditions, small holes with the diameter of 25 microns can be drilled.

Enhanced UV Laser-Induced Damage Tolerance in CsLiB 6 O 10 by Reducing Water Molecule Impurities in the Crystal Volume

We revealed the harmful effects of water molecules in CsLiB6O10crystal volume on ultraviolet light generation. The reduction of impurities results in lowering nonlinear absorption at 266 nm and significantly enhancing the laser-induced damage tolerance.