Concentration

1. What is the doping concentration of crystal？ The doping concentration of crystal refers to the percentage of the mass of doped rare earth elements to the total mass. 2. How to express the impurity concentration of crystal？ 2.1 Mass percent concentration Mass percent concentration (mass fraction, m/m): most commonly used. It refers to the mass of solute contained in per 100 g of solution. Mass percentage concentration = (solute mass (g) / solution mass (g)) × 100% = solute mass (g) / (solute mass (g) + solvent mass (g)) × 100%. 2.2 Volume fraction Volume fraction (volume fraction, V/V): …

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Schematic-diagram-of-focal-length-changes-caused-by-weak-absorption-of-materials

Jan 31 2023February 1, 2023

Weak absorption test of crystalline materials

1. Why measure weak absorption? The absorption of optical material or optical film will directly affect the performance of optical system.The material has thermal lensing effect. As shown in the schematic diagram of focal length change caused by weak absorption of materials, when a lens is irradiated by a strong laser, the medium can periodically convert the absorbed energy into heat energy, which increases the temperature of the material itself and the surrounding medium, thus causing the change of its refractive index, resulting in the change of the focal length of the lens, forming the thermal lens effect, resulting in …

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Sep 30 2022April 12, 2023

How to choose Nd: YAG, Nd: YVO4, Nd: YLF, and Nd: Glass?

Nd: YVO4 and Nd: YAG are the industry’s most mature solid-state laser media. The absorption wavelength of the Nd-doped laser gain medium is mainly around 0.8 um, which is suitable for direct semiconductor pumping. The output wavelength has three bands of 0.9 um, 1.0 um, and 1.3 um. Among them, 0.9 and 1.3 um are quasi-three levels with low efficiency. The wavelength of 1.3 μm is suitable for two-photon microscopy and communication. The wavelength of 0.9 μm has an absorption peak of water molecules, which is suitable for atmospheric detection. Industrial processing is mainly used in the 1um band, with …

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Jul 27 2022April 12, 2023

Phase matching angle

1. Phase matching The physical essence of phase matching is to make the frequency doubled light excited by the fundamental frequency light at each point along the crystal have the same phase when propagating to the emitting surface, so that they can interfere with each other and enhance each other, so as to achieve a good frequency doubling effect. 2. Constraints of phase matching In order to realize the effective conversion of nonlinear wavelength, it is necessary to meet the conservation of photon energy and photon momentum at the same time in the process of nonlinear optics. Photon momentum conservation …

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Crystals