JPS6017913Y2 - Light stabilized gas laser device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas laser device, and particularly to a light-stabilized gas laser device that can provide stable output.

Conventionally, as shown in FIG. 1, this type of device includes a gas laser tube 10, an output side mirror 11 and a high-reflection mirror 12, which are arranged at both ends of the tube and constitute a resonator mirror, and this high-reflection mirror 12. Detects a small amount of laser light 13 that has passed through the laser beam, and converts it from the photoelectric conversion element 16 that controls the excitation power source 15 via the amplifier 14, and outputs discharge light having a certain relationship with the laser output 17 from the photoelectric conversion element 16. It is configured to obtain a stable laser output 17 by controlling according to the signal.

By the way, in the case of a small output laser device, the absolute amount of the laser beam 13 passing through the high reflection mirror 12 is very small.

Normally, the transmittance of the high reflection mirror 12 is between 0.05% and 0.05%.
02%, and the transmittance of the output side mirror 11 is from several % to 1.5%.
That's about it.

Here, for an argon ion laser with an output of 10 rrlW, if the transmittance of the output side mirror 11 is 3% and the high reflection side mirror 12 is 0.05%, the laser beam 13 transmitted through the high reflection side mirror 12 is 0.0005.

10mW x −=0.17mW.

Laser output: 0.03 When stabilizing operation is started when the light level reaches the rated output of 1710, an optical signal strength of 1110 of 0.17 mW, that is, 17 μW is required.

If such a small optical signal intensity is taken as the operating intensity, the intensity of the discharge light 18 generated due to discharge excitation of the gas laser tube 10 becomes a problem.

In other words, as shown in FIG. 2, although this discharge light 18 is smaller in density than the laser light 13, it is
Since it acts on the entire light-receiving surface of the laser beam 13, the ratio of the area of the entire light-receiving surface to the area irradiated with the laser beam 13 becomes larger.

Therefore, the converted signal is supplied together with the converted signal of the laser beam 13 as a control signal for the excitation power source 15.

This discharge light, which is extremely unstable both in terms of spectrum and intensity, is superimposed on the control signal as noise, making it impossible to perform stable control, especially in low-output laser devices. This may be difficult, or there may be too many noise components.

As a countermeasure against this problem, as seen in Japanese Utility Model Publication No. 44-18589, there is an example in which a filter for extracting monochromatic light is provided between the reflecting mirror and the detector.

However, in this case, it is necessary to separately prepare an optical filter, which has a disadvantage in terms of economy, which hinders its practical use.

The present invention eliminates such drawbacks by providing a dielectric multilayer film on the outer surface of the high-reflection mirror of the internal mirror gas laser tube to suppress light with wavelengths outside the reflection band of the high-reflection mirror. The object of the present invention is to provide a practical optically stabilized gas laser device that suppresses light and therefore removes noise components and can operate stably.

An embodiment of the present invention will be described below with reference to FIG.

In addition, in this embodiment, as shown in FIG. 3, a derivative having spectral characteristics that suppresses light of wavelengths outside the reflection band of the high reflection mirror is attached to the outer surface of the high reflection mirror 61 of the internal mirror gas laser tube 60. A multilayer film 62 is provided.

This dielectric multilayer film 62 will be explained below with reference to FIGS. 4 to 6.

First, as shown in FIG.
An argon ion laser tube with many spectra in the wavelength band from nm to 500 nm, and a high reflection mirror 61
As shown in FIG. 7, a mirror having characteristics as shown by a in FIG.
A silicon solar cell with sensitivity from 400 nm to 11 QQ nm is used.

Under this condition, 4201 m in the discharge spectrum
to 500 nm is 99.8% with the high reflection mirror 61.
The light is reflected and is not supplied to the photoelectric conversion element 23.

Also, for spectra shorter than 420r1m,
Since this is outside the sensitivity of the photoelectric conversion element 23, there is no problem with the noise level.

The spectrum in question is a wavelength longer than 5500 nm transmitted through the high reflection mirror 61 and the longest spectrum emitted from the laser tube 60, that is, 920 nm.
That's about it.

Although the amount of light emitted with a wavelength between 5501 m and 920 nm is small, it poses a problem as described in the description of the conventional example.

Therefore, as the dielectric multilayer film 62 formed on the high reflection mirror 61, as shown by b in FIG. It is possible to suppress the light that causes

Specifically, the high reflection film for He-NeLz-zer and 82
This can be achieved by forming double layers of high reflection films with center wavelengths in the vicinity of 0.01 m to 830 nm.

With this configuration, the present invention makes it possible to stabilize the laser output with a signal with fewer noise components by using the existing high-reflection mirror without installing a new optical filter glass. Laser output can be obtained.

[Brief explanation of the drawing]

Figure 1 shows the constituent countries for explaining conventional equipment, Figure 2 a,
b is the same〈A partial configuration diagram and a diagram showing the received light spectrum for explaining the conventional device, Figure 3 is the constituent country for explaining one embodiment of the present invention, and Figures 4 to 6 are for the present invention. FIG. 2 is a diagram showing the power and strength characteristics of the constituent countries for explaining one embodiment of the present invention. In the figure, 14 is an amplifier, 15 is an excitation power source, 17 is a laser output, 23 is a photodetector, 60 is an internal mirror gas laser tube, 61 is a high reflection mirror, 62 is a dielectric multilayer film, and 27a
is a laser beam.

Claims (2)

[Scope of utility model registration request] (1) A device that detects a laser beam outputted after passing through a high-reflection mirror of an internal mirror gas laser oscillation unit with a photodetector, and feeds back the signal to the laser oscillation unit to stabilize the laser output, A light-stabilized gas laser device characterized in that a dielectric multilayer film having spectral characteristics that suppresses light of wavelengths outside the reflection band of the high-reflection mirror is formed on the outer surface of the high-reflection mirror. (2) Utility model registration claim 1, characterized in that a dielectric multilayer film having high reflection characteristics is formed on the outer surface of the high reflection mirror on the longer wavelength side than its reflection band. Light-stabilized gas laser device.