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 …
