抄録
When a laser beam irradiates a sample, a small amount of the incident energy is locally absorbed by the sample along the laser beam. When this local heating occurs, the refractive index of the medium also changes locally along the beam, and the entire medium acts as a lens. This effect is called thermal lens effect. Recently, the application which uses the thermal lens effect to the density measurement etc. starts, And near future, the device which switch from light to light without changing electricity will be expected. In this research, we discuss about various wavelength and modulation frequency noting the expansion for the light switching device using for wavelength division multiplexing and femto second spectroscopic measurement.
