JPH03274780A - Gas laser device - Google Patents

Abstract

PURPOSE:To prevent deviation of alignment of an optical system even if an operation is continued for a long time by securing a fan, a motor of a vibration source on a second surface plate, and disposing the plate on a first surface plate secured to an optical system through vibration absorbing means. CONSTITUTION:A gas laser tube 1 and a motor 3 for driving a fan 2 for circulating laser gas contained in the tube 1 are secured on a surface plate 10 (second surface plate). An optical system 6 such as a front mirror, a rear mirror, an etalon, etc., for a laser oscillation, a wavelength control, and a position detector 11 for detecting the relative position between the system 6 and the tube 1 are provided on a surface plate 7 (first surface plate). Pneumatic spring (air suspension) 20 is mounted as vibration absorbing means between the plates 7 and 10 thereby to insulate the vibration of the plate 10 in which vibration sources such as the fan 2, the motor 3, etc., are secured from the system 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-output gas laser device such as an excimer laser that requires cooling the gas in the laser tube by circulating it, and particularly relates to a fan and a gas laser device for gas circulation. The present invention relates to a vibration isolation structure for a gas laser device equipped with a motor for driving the fan.

[Conventional technology]

Conventional technology for this type of gas laser device is shown in FIGS. 2 and 3.

In these figures 2 and 3, 1 is a gas laser tube, 2
is a fan for circulating laser gas, 3 is fan 2
4 is a radiator for cooling the circulated laser gas; 5 is an optical window that transmits laser light and is sealed so that the laser gas inside does not leak; 6
7 is an optical system for controlling laser oscillation and wavelength, 7 is a surface plate for fixing the laser device, and 8 is a vibration isolating rubber for preventing the laser device from receiving vibrations from a floor 9 or the like.

The laser gas receives energy through a discharge between electrodes (not shown) and converts a portion of it into light. The light is amplified between the front and rear mirrors included in the optical system, and is emitted as a laser beam. At this time, most of the received energy is converted into heat, which is circulated by the fan 2 and cooled by the radiator 4.

[Problem to be solved by the invention]

In the conventional laser device shown in FIG. 2, the gas laser tube 1 and the optical system 6 are fixed on the same surface plate 7, so the vibrations of the motor 3 and fan 2 are directly transmitted to the optical system 6. Become.

For this reason, when the operation continues for a long time, the alignment of the optical system 6 (relative position and angular relationship of optical elements) shifts, resulting in a decrease in laser output and a shift in wavelength. Therefore, it is conceivable to perform optimal position control on all optical systems 6 using a control means such as a pulse motor, but if such control is performed on all optical elements, the device becomes complicated. Not only is this expensive, but the control is also complicated. Also, if the vibration becomes intense,
The control could not keep up and eventually the equipment had to be stopped.

Furthermore, as shown in FIG. 3, there is a device in which the optical system 6 is integrated with the laser tube 1, but this is still the same in that the alignment of the optical system is shifted due to the vibration of the laser tube 1.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a gas laser device equipped with an anti-vibration structure that can prevent misalignment of the optical system even after long-term operation.

[Means to solve the problem]

In this invention, an optical system for laser oscillation is fixed on a first surface plate, and a second surface plate is fixed on this first surface plate via a vibration absorbing member such as an air spring, Furthermore, a gas laser tube having a built-in fan for circulating laser gas and a motor for driving the fan are fixed on the second surface plate.

[Effect]

According to this configuration, the fan or motor as a vibration source is fixed on the second surface plate, and this second surface plate is placed on the first surface plate fixed to the optical system via the vibration absorbing means. are doing.

That is, between the vibration source and the optical system, the first. A second surface plate and a vibration absorbing member are also interposed.

〔Example〕

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 1 is the first of the constituent elements shown in FIG.

Components that are the same as those shown in FIG. 2 are given the same reference numerals.

In this gas laser device, the surface plate 10 (second surface plate)
A motor 3 for driving a gas laser tube 1 and a fan 2 for circulating the laser gas contained in the gas laser tube 1 is fixed on the top. 4 is a heat exchanger, 5 is an optical window, 8 is a vibration-proof rubber, and 9 is a floor.

Also, on the surface plate 7 (first surface plate), there is an optical system 6 such as a front mirror and a rear mirror etalon for laser oscillation and wavelength control, and the relative position of these optical systems 6 and the gas laser tube 1 is detected. A position detector 11 is provided.

An air spring (air suspension) 20 as a vibration absorbing means is installed between the surface plate 7 and the surface plate 10, and this air spring 20 causes the fan 2. A surface plate 10 to which a vibration source such as a motor 3 is fixed is vibration-insulated from an optical system 6.

Therefore, fan 2. Even if the motor 3 vibrates, this vibration will not propagate to the optical system 6.

On the other hand, since the optical system 6 is firmly fixed on the surface plate 7, it is less likely to be out of alignment due to the influence of heat, and can continue to oscillate with a constant power.

The misalignment of other optical elements can also be kept within a control range, and the configuration of the laser device can be simplified.

The position detection device 11 detects the vertical and horizontal positions of the gas laser tube 1 by optically detecting, for example, a mark written on the side surface of the gas laser tube 1 or a light emitting body 12, and outputs the detection output to the pneumatic controller 30 manually. Since the position detection device 11 is fixed on the common surface plate 7 with the optical system 6, the output of the position detection device 11 ultimately represents the relative position between the optical system 6 and the gas laser tube 1. Become.

The pneumatic controller 30 calculates the deviation of the detected output of the position detecting device 11 from a reference value (the detected output value of the position detecting device 11 when the gas laser tube 1 and the optical system 6 are normally positioned), and calculates the deviation from this deviation. Both relative positional deviations are detected, and the air pressure of each air spring 20 is adjusted and controlled so that this deviation becomes zero. That is, this air spring adjustment control prevents misalignment between the optical axis of the laser and the optical axis of the optical system 6.

In this manner, according to this embodiment, the vibration source is vibration-insulated from the optical system, so that misalignment of the optical system and other optical elements can be kept within an allowable range.

Note that the position detector 11 is not limited to the one shown in the embodiment, and any method may be used as long as it can detect the relative position between the gas laser tube 1 and the optical system 6. .

〔Effect of the invention〕

As explained above, according to the present invention, vibration isolation is achieved by the vibration source, the optical system, and the vibration absorption means in the gas laser device, so misalignment of the optical system and misalignment of the optical axis are suitably prevented, and The quality of laser light is less likely to deteriorate (shifting the center wavelength or changing the transverse mode),
Furthermore, not only the device configuration is simplified, but also the power and wavelength control are simplified, and other excellent effects are achieved.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIGS. 2 and 3 are schematic diagrams of the prior art. DESCRIPTION OF SYMBOLS 1... Gas laser tube, 2... Fan, 3... Motor, 4... Heat exchanger, 5... Optical window, 6... Optical system, 7.10... Surface plate, 8... Anti-vibration rubber, 9...
floor, 11... position detection device, 20... air spring, 3
o...Air pressure controller Fig. 2 0 Fig. 1 Fig. 3

Claims (3)

[Claims] (1) An optical system for laser oscillation is fixed on a first surface plate, a second surface plate is fixed on this first surface plate via a vibration absorbing member, and further, an optical system for laser oscillation is fixed on the first surface plate. A gas laser device characterized in that a gas laser tube having a built-in fan for circulating laser gas on a panel and a motor for driving the fan are fixed. (2) The gas laser device according to claim (1), wherein the vibrating member is an air spring. (3) a position detecting means for detecting the relative position between the gas laser tube on the second surface plate and the optical system on the first surface plate; and adjusting the air pressure of the air spring according to the output of the position detecting means. The gas laser device according to claim 2, further comprising: an air pressure adjusting means for adjusting.