Abstract: A state of attenuation in total internal reflection is detected by the use of a measuring apparatus having a measuring unit and a reference unit and a measuring system which corrects result of detection by the measuring unit on the basis of result of detection by the reference unit and measures the change of a state of attenuation in total internal reflection on the basis of the corrected result of detection by the measuring unit. The difference in sensitivity between the measuring unit and the reference unit is detected before initiating the measurement of the change of a state of attenuation in total internal reflection, and result of measurement by the measuring system is calibrated on the basis of the difference in sensitivity between the measuring unit and the reference unit.

Abstract: A state of attenuation in total internal reflection is detected by the use of a measuring apparatus having a measuring unit and a reference unit and a measuring system which corrects result of detection by the measuring unit on the basis of result of detection by the reference unit and measures the change of a state of attenuation in total internal reflection on the basis of the corrected result of detection by the measuring unit. The difference in sensitivity between the measuring unit and the reference unit is detected before initiating the measurement of the change of a state of attenuation in total internal reflection, and result of measurement by the measuring system is calibrated on the basis of the difference in sensitivity between the measuring unit and the reference unit.

Abstract: A solid-state laser crystal constituting a laser-diode-excited solid-state laser apparatus or an optical fiber constituting a fiber laser apparatus or fiber laser amplifier is doped with one of Ho3+, Sm3+, Eu3+, Dy3+, Er3+, and Tb3+ so that a laser beam is emitted from the solid-state laser crystal or the optical fiber, or incident light of the fiber laser amplifier is amplified, by one of the transitions from 5S2 to 5I7, from 5S2 to 5I8, from 4G5/2 to 6H5/2, from 4G5/2 to 6H7/2, from 4F3/2 to 6H11/2, from 5D0 to 7F2, from 4F9/2 to 6H13/2, from 4F9/2 to 6H11/2, from 4S3/2 to 4I15/2, from 2H9/2 to 4I13/2, and from 5D4 to 7F5. The above solid-state laser crystal or optical fiber is excited with a GaN-based compound laser diode.

Abstract: A semiconductor-laser-pumped solid state laser includes a solid state laser medium doped with a rare earth element such as neodymium and a semiconductor laser which emits a pumping laser beam for pumping the solid state laser medium. A pumping light incident side end face of the solid state laser medium is fixed to a holder.

Abstract: A semiconductor laser pumped solid state laser includes a solid laser medium, a semiconductor laser which radiates a pumping laser beam for pumping the solid laser medium, and a light entrance optical system which converges the pumping laser beam in the solid laser medium. The semiconductor laser is disposed with its beam radiating axis inclined to the optical axis of the light entrance optical system so that the pumping laser beam travelling from the semiconductor laser to the solid laser medium and a laser beam reflected at the pumping light inlet side end face of the solid laser medium travel different optical paths. A light-shielding plate which intercepts the laser beam reflected at the pumping light inlet side end face of the solid laser medium is provided between the semiconductor laser and the solid laser medium.

Abstract: In a laser-diode-pumped solid state laser, a solid laser crystal is pumped by a pumping laser beam emitted from a laser diode and a harmonic of light emitted from the pumped solid laser crystal is caused to make laser oscillation by a resonator structure containing therein a nonlinear optical crystal. The electric current to be poured into the laser diode is controlled so that the pumping laser beam emitted from the laser diode is kept at an output level at which the pumping laser beam cannot cause the harmonic of light emitted from the solid laser crystal to make laser oscillation though pumping the solid laser crystal.

Abstract: A laser-diode-pumped solid state laser in which a solid state laser crystal is pumped by a light beam produced by a laser diode and which is not lower than 10 W in the internal power of the resonator includes a temperature control circuit which keeps the inside temperature of a resonator at a predetermined temperature and, a wavelength selector which is disposed in the resonator and selects one of a plurality of oscillation modes in the resonator, thereby making the laser oscillate in a single mode. The wavelength selector has characteristics such that the increase in temperature of the wavelength selector due to absorption of a laser beam is smaller than a value such that when the temperature of the wavelength selector changes by the value or more, the oscillation mode selected by the wavelength selector changes.

Abstract: A laser diode pumped solid laser comprises an optical module comprising a laser diode, a solid laser crystal, which is excited by a laser beam produced by the laser diode, and a resonator. An electronic cooling device has a cooling surface, on which the optical module is placed, and a heat radiating surface. An inner case housing houses the optical module therein on the cooling surface of the electronic cooling device. An outer case housing houses the inner case housing and the electronic cooling device therein and supports the electronic cooling device via its heat radiating surface. A temperature sensor detects the temperature in the region inside of the inner case housing. A control circuit controls the electronic cooling device in accordance with an output of the temperature sensor and thereby keeps the temperature in the region inside of the inner case housing at a predetermined target value.