JPH0747892Y2 - Variable output solid state laser oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a solid-state laser oscillator, and more particularly to a variable output solid-state laser oscillator required in the field of laser processing.

[Conventional technology]

Conventionally, when continuously changing the output of a solid-state laser oscillator according to the processing application, the pumping input level was made variable or an output attenuator was used outside the resonator.

[Problems to be solved by the invention]

Among the above-mentioned conventional methods, in the method of changing the pumping input level, the thermal lens effect amount generated in the solid-state laser medium changes, and as a result, the stability condition of the resonator changes and the laser output stability changes with the output level. There is a drawback that.

In addition, the method of adjusting the output by installing a variable transmittance attenuator outside the resonator requires an additional optical attenuating element such as a laser reflecting mirror and a polarizer, which causes a cost increase and an unnecessary laser output. A heat dissipation plate is required to absorb the heat, which has the drawback of increasing the installation space.

Therefore, an object of the present invention is to provide a solid-state laser oscillating device which requires a small number of optical components and which can be continuously varied under stable conditions.

[Means for solving problems]

In the variable output type solid-state laser oscillator according to the present invention, the variable shape aperture mechanism is provided inside the solid state laser resonator having the output mirror and the total reflection mirror, and the variable shape aperture mechanism is electrically controlled outside. In a solid-state laser oscillating device having an aperture drive circuit and variable laser output, the leaked light from the internal output of the oscillator that inevitably passes through the total reflection mirror outside the total reflection mirror is converted into an electric signal. A photodetector is provided, and an arithmetic circuit for computing the output of the photodetector and feeding it back to the aperture driving circuit is provided. By changing the shape of the aperture by such a structure, it is possible to give a desired change to the laser output while keeping the pump input level constant, and to feed back the laser output level to the variable aperture drive circuit.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. Excitation lamp 12 in which solid-state laser rod 11 is driven by laser power supply 13
As a result, the transverse mode laser emission is generated between the laser resonator constituted by the output mirror 14a and the total reflection mirror 14b. The variable shape aperture mechanism (for example, polygonal variable aperture mechanism) 15 is a variable aperture drive circuit.
The shape such as the aperture diameter is electrically controlled by 16 and the diffraction loss for the oscillation transverse mode is controlled. As a result, the output level of the laser output beam 17 can be electrically controlled.

FIG. 2 is a block diagram of a second embodiment of the present invention. In this configuration, the leak light 18 of the oscillator internal output which is inevitably transmitted through the total reflection mirror 14b is monitored by using the photodetector 19, and its electrical output is supplied through the arithmetic circuit 20 to the variable aperture drive circuit 16
By feeding back to, it is possible to perform control such as maintaining a constant value of the laser output and automatically setting to a preprogrammed output level.

[Effect of device]

As explained above, in the solid-state laser according to the present invention, it is possible to control the laser output by controlling the diffraction loss of the resonator by means of the variable shape aperture installed in the resonator. As a result, it is not necessary to change the pump lamp input. It does not cause instability of the laser output and at the same time does not require extra optical parts. Further, since the oscillation output is controlled inside the resonator, unnecessary laser output is not sent out of the resonator. Further, since the laser output level can be fed back, it is possible to maintain the laser output at a constant value and automatically set the output level to a preprogrammed output level.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a variable output solid-state laser device according to the present invention, and FIG. 2 is a block diagram of a second embodiment. Symbol description: 11 …… Solid laser rod, 12 …… Excitation lamp, 13 …… Laser power supply, 14a …… Output mirror, 14b …… Total reflection mirror, 15 …… Variable shape aperture mechanism, 16 …… Variable aperture Drive circuit, 17 ... Laser output beam, 18 ... Leakage light, 19 ... Photodetector, 20 ... Arithmetic circuit.

Claims (1)

[Scope of utility model registration request] 1. A variable shape aperture mechanism is provided inside a solid-state laser resonator having an output mirror and a total reflection mirror,
A solid-state laser oscillating device having an externally provided aperture driving circuit for electrically controlling the variable shape aperture mechanism to make a laser output variable, wherein a transmission unavoidably transmitted through the total reflection mirror to the outside of the total reflection mirror. An output is characterized by being provided with a photodetector for receiving the leak light of the internal output of the device and converting it into an electric signal, and further provided with an arithmetic circuit for computing the output of this photodetector and feeding it back to the aperture drive circuit. Tunable solid-state laser oscillator.