Diode-pumped solid-state laser oscillator
View Patent ↗A diode-pumped solid-state laser oscillator optically pumps a laser medium. The oscillator has at least one pumping light source that emits light in a predetermined wavelength band, and a laser medium that absorbs light in the wavelength band. In the wavelength band, the optical absorption index of the laser medium increases with an increase in wavelength, and the optical radiation energy of the light source decreases with an increase in wavelength. Thus, with respect to wavelength changes, an increase in the optical absorption index is cancelled out by a decrease in the radiation energy, making the stability of the laser output less dependent on the temperature of the optical pumping medium or laser medium.
1. A diode-pumped solid-state laser oscillator comprising:
a laser medium configured to absorb light in a band of a wavelength and have an optical absorption index that increases with an increase in wavelength;
at least two pumping light sources, each of which is configured to emit light at the wavelength, and have optical output power that decreases at the wavelength with an increase in temperature, in which the wavelength increases with an increase in temperature; and
a switch configured to switch one of the light sources to another light source in accordance with changes in temperature of an operating environment at a temperature point at which a change in an integral of a product that constitutes optical energy absorbed by the laser medium is made smaller using said another light source.
2. A diode-pumped solid-state laser oscillator comprising:
a laser medium that absorbs light at a pair of first and second wavelengths of different absorption bands, in which at the first wavelength an optical absorption index increases according to an increase in wavelength, and at the second wavelength an optical absorption index decreases according to an increase in wavelength;
a switch; and
plural pairs of first and second pumping light sources that emit light in said first and second selected wavelengths at different temperatures, one pair being switched by said switch to another pair in accordance with changes in temperature of an operating environment at a temperature point at which a change in an integral of a product that constitutes optical energy absorbed by the laser medium is made smaller using said another pair.
3. A diode-pumped solid-state laser oscillator comprising:
a plurality of pumping light sources configured to emit light in a plurality of selected wavelength bands, respectively;
a laser medium configured to absorb light of each wavelength; and
a switch,
wherein a temperature dependency of a summation of integrals of a product of spectrum intensity distribution of each of the pumping light sources and optical absorption index distribution of the laser medium over a spectrum of each pumping light source, which integrals are in terms of wavelength, is lower than a temperature dependency of an integral of a product of spectrum intensity distribution of any one of the pumping light sources and the optical absorption index of the laser medium, which integral is in terms of wavelength, and
wherein said plurality of pumping light sources comprise plural sets of pumping light sources, each set of pumping light sources emits light in a plurality of selected wavelength bands at different temperature ranges, and one set is switched by said switch to another set in accordance with changes in temperature of an operating environment at a temperature point at which a change in an integral of a product that constitutes optical energy absorbed by the laser medium is made smaller using said another set.
4. A diode-pumped solid-state laser oscillator comprising:
at least one pumping light source configured to emit light in a selected wavelength band and have optical output power decreasing in said selected wavelength band with an increase in temperature, in which wavelength of the light increases with an increase in temperature;
a laser medium configured to absorb light in said wavelength band and have an optical absorption index, said laser medium having a wavelength distribution which increases with an increase in wavelength in said selected wavelength band;
a Peltier thermal insulation element in contact with said at least one pumping light source; and
a control device configured, with respect to heat removal from said at least one pumping light source, to control a light-source temperature in response to environmental temperature by adjustment of thermal conductivity of the Peltier thermal insulation element to a high or low value in a high- or low-temperature environment,
wherein said at least one pumping light source comprises a set of pumping light sources having higher temperature than the environmental temperature.
5. A diode-pumped solid-state laser oscillator comprising:
at least one pair of first and second pumping light sources configured to emit light in a pair of first and second selected wavelength bands, respectively;
a laser medium configured to absorb light in said pair of selected wavelength bands and have an optical absorption index, said laser medium having a wavelength distribution that decreases in said first selected wavelength band with an increase in wavelength and increases in said second selected wavelength band with an increase in wavelength;
a Peltier thermal insulation element in contact with said pair of first and second pumping light sources having higher temperature than environmental temperature; and
a control device configured to control with respect to heat removal from at least one pumping light source and to control a light-source temperature in response to the environment temperature by adjustment of thermal conductivity of the Peltier thermal insulation element to a high or low value in a high- or low-temperature environment.
6. A diode-pumped solid-state laser oscillator comprising:
a plurality of pumping light sources configured to emit light in a plurality of selected wavelength, bands, respectively;
a laser medium configured to absorb light of each wavelength;
a Peltier thermal-insulation element in contact with said plurality of pumping light sources having higher temperature than environmental temperature; and
a control device configured to control with respect to heat removal from at least one pumping light source and to control a light-source temperature in response to the environmental temperature by adjustment of thermal conductivity of the Peltier thermal-insulation element to a high or low value in a high- or low-temperature environment,
wherein a temperature dependency of a summation of integrals of a product of spectrum intensity distribution of each of the pumping light sources and optical absorption index distribution of the laser medium over a spectrum of each pumping light source, which integrals are in terms of wavelength, is lower than a temperature dependency of an integral of a product of spectrum intensity distribution of any one of the pumping light sources and the optical absorption index of the laser medium, which integral is in terms of wavelength.