JPH0212981A - Piezoelectric lens insertion type solid state laser resonator - Google Patents

Abstract

PURPOSE:To realize the stabilization of an optical output by disposing a piezoelectric concave lens system, continuously compensating a thermal lens effect and holding an optimum resonant state. CONSTITUTION:Focal lengths of piezoelectric concave lenses 2, 4 are varied in response to an output power from a resonator formed of a rear mirror 1, the lens 2, a laser rod 3, the lens 4, and front mirror 5, and so composed as to hold an optimum resonant state. A piezoelectric material employs a piezoelectric lens of a PLZT transparent material to spectrally separate a light by the shape change of the lens. That is, the light incident to the mirror 1 is distributed to lights having different frequencies and low energy lights, matched under phase matching conditions by an optical resonator 3, the focal length is condensed by the lens 4, and a coherent light of necessary frequency can be output by the optical filter 5.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to improvements in solid-state laser resonators used in laser processing, optical measurement, and the like.

(Prior Art) FIG. 2 is an overall configuration diagram of a solid-state laser resonator according to the prior art. By placing nonlinear optical elements (Limb's) (6) between a pair of optical resonators (7),
The light (ν1) is placed in an oscillation state by the generation mechanism of the effect (optical parametric effect) of a nonlinear optical element.The light control optical system (9) (ν,)
(pumping frequency 0.53 μm) is separated, and the necessary light (ν2) (output frequency 0.96 μm) and unnecessary light (ν, ) (idler frequency 1.18 μm) are passed straight through an optical filter (8 ) by passing the light (ν2
) becomes oscillating. In other words, a high-energy photon is split into two low-energy photons and released. (Fundamentals of Optoelectronics IM: Keigaku Publishing, January 1984, p. 80) In this way, since optical parametric effects can be used to adjust coherent light, the following application methods are being considered as light control technology. There is. One method is to detect the internal beam shape and output of the light during oscillation by monitoring the beam shape and intensity inside the resonator with a beam splitter, and the data on the beam diameter and light intensity are stored in a computer. Optimize by calculating the internal beam shape and output of the input light. In this case, the control system is composed of a piezo micrometer and a pulse meter.

Instead of such a method of controlling the optical system using a beam splitter system, a method of controlling light using a piezoelectric module has also been considered.

(Problem to be solved by invention) However, in the conventional technology, a method is adopted in which the end face of the laser rod is machined into a concave surface, but with this method, the laser input increases and a thermal lens effect must occur to some extent. Because there are optical phenomena that overcompensate, they tend to act as concave lenses.

In the conventional optical system as described above, since only the output power is monitored, fluctuations in gain are fed back to the adjustment of the optical system, resulting in unstable output of the control system.

(Means and effects for solving the problem) In view of this, the present invention continuously compensates for the thermal lens effect of the laser rod by using a piezoelectric concave lens between the rear mirror and the front mirror of the solid-state laser resonator. This enables oscillation from low power.

(Example) The present invention will be described below with reference to an example shown in FIG.

In Figure 1, a rear mirror (1), a piezoelectric concave lens (2)
), a laser rod (3), a piezoelectric concave lens (4), and a front mirror (5). It is configured to maintain A piezoelectric lens made of a PLZT-based transparent material is used as the piezoelectric material, and light is separated into lights by changing the shape of the piezoelectric lens. In other words, the light (νo+) that enters the rear mirror (1) passes through the piezoelectric concave lens (A) (2), and the light (ν.2) and the light (ν.
ν. , ) is distributed into low-energy light called optical resonator ( ).
After adjusting the phase matching conditions in 3), the piezoelectric concave lens (B)
(2), the focal length is focused by the optical filter (5
) can output coherent light (ν., ) at the required frequency.

Since the method of the present invention has controllability in phase matching conditions, etc., it can be widely applied in the field of optoelectronics, including the above-mentioned laser processing and optical measurement.

(Effects of the Invention) The solid-state laser resonator according to the present invention can realize stabilization of optical output by arranging a piezoelectric concave lens system to continuously compensate for thermal lens effects and maintain an optimum resonance state.

[Brief explanation of the drawing]

Fig. 1 Overall configuration diagram showing an embodiment of the present invention Fig. 2 Overall configuration diagram according to conventional technology - Rear mirror - Piezoelectric lens (A) - Laser rod - Piezoelectric lens (B) - Front mirror - Nonlinear optical element (LiNb0s ) ・Optical resonator・Optical filter・Light control optical system Fig. 1 Fig. 2 ν1 C1: Pumping frequency (0.53 μm) C2: Output frequency (0.96 μm)

Claims (1)

[Claims] A piezoelectric lens-inserted solid-state laser resonator characterized in that a piezoelectric concave lens with a variable focal length is inserted between a rear mirror and a front mirror of the solid-state laser resonator to compensate for the thermal lens effect of the laser rod.