JPS62291189A - He-ne gas laser apparatus - Google Patents

Abstract

PURPOSE:To stabilize a laser output by providing a light-receiving element for receiving a laser beam reflected by a beam splitter and by providing in a power source a circuit for controlling a current flowing through a solenoid coil on the basis of a signal from the light-receiving element. CONSTITUTION:Based on an output signal of a light-receiving element 8, a control circuit 10 for controlling a current flowing through a solenoid coil 9, which is disposed in a power source, controls an output value by a discharge current in an Ar laser, for instance. In the case when a laser output value is varied due to some cause, the variation is detected by a beam splitter 5 and the light-receiving element 8, and when a laser output turns lower than a prescribed value, the current flowing through the solenoid coil 9 is increased so that the output is restored to the prescribed output value. Thereby the intensity of a magnetic field is increased and the output value is raised. When the laser output increases, on the other hand, the current is reduced to execute a control so as to lower the output to the prescribed output value. By this method, the output value can be maintained at a prescribed level.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a He--Ne gas laser device, and particularly to a structure for stabilizing laser output.

[Conventional technology]

Conventionally, this type of He-Ne gas laser device consists of a gas laser tube, a casing for holding and fixing the gas laser tube, and a power source.In order to suppress fluctuations in laser output due to environmental changes such as changes in ambient temperature, The above-mentioned casing was constructed using a material such as Invar, which has a low coefficient of thermal expansion.

[Problem that the invention seeks to solve]

In the conventional He-Ne gas laser device described above, the laser tube is held and fixed in order to suppress fluctuations in laser output caused by misalignment of the mirror due to environmental changes such as changes in ambient temperature. A material with a low coefficient of thermal expansion was used for the housing. However, with this configuration alone, the temperature range in which changes in laser output can be suppressed is narrow, and if unnecessary force is applied to the housing from the outside and the mirror adjustment shifts considerably, it is difficult to suppress the change in laser output due to this. It is completely impossible to suppress this, and there are drawbacks such as the fact that it cannot be used in applications that require high output stability.

[Means for solving problems]

The present invention provides a He-Ne gas laser device that includes a gas laser tube, a housing for holding the gas laser tube, and a power source, in which a solenoid coil is attached to a narrow tube portion of the gas laser tube to reflect a portion of the laser beam. The power source is equipped with a beam spiriter, a light-receiving element for receiving the laser light reflected by the beam spiriter, and a control circuit that controls the current flowing through the solenoid coil based on the signal from the light-receiving element. Features.

〔Example〕

Next, the present invention will be explained using the drawings.

FIG. 1 shows a schematic diagram of an embodiment of the present invention. In Fig. 1, 1 is a laser tube, 2 is a housing made of Af, etc., 3 is a power supply,
4 is a laser beam, 5 is a beam spiriter, 6.7 is a laser beam transmitted and reflected by the beam spiriter 5, 8 is a light receiving element such as a solar cell that receives the laser beam 7, 9 is a discharge part of the laser tube 1 In other words, the solenoid coil wound around the thin tube part,
Reference numeral 10 denotes a control circuit disposed inside the power supply that controls the current flowing through the solenoid coil 9 based on the output signal of the light receiving element 8, and is generally used, for example, to control the output value using the discharge current in Ar lasers, etc. This is the same control circuit as the one above, and these constitute the He-Ne gas laser device.

The operation of the He-Ne gas laser device of the present invention will be explained. For He-Ne gas laser, 632.8o
It is known that the oscillations at 3.39 μm and 3.39 μm have competitive oscillation characteristics, and among these, the oscillation at 3.39 μm is known to depend on the strength of the applied magnetic field. Therefore, when a current is applied to the solenoid coil 9 attached to the thin tube and a magnetic field is applied, the 3.39 μm oscillation changes depending on the strength of the applied magnetic field, and the output value at the 632.8 ohm wavelength is shown in Figure 2. It changes like this. In the present invention, this development is utilized to stabilize the laser output of 632.8 ohm. Now, if the laser output value fluctuates for some reason, the fluctuation is detected by the beam spiriter 5 and the light receiving element 8. For example, if the laser output drops below the specified value, the solenoid is activated to maintain the specified output value. By increasing the current flowing through the coil 9 from a value Ip corresponding to the normal operating point l-P shown in FIG. 2, the magnetic field strength is increased and the output value is increased. Conversely, when the output increases, the current Ip
The output value can be kept constant by controlling the output value to decrease to a specified output value.

Although an example of an internal mirror type laser tube is shown in the above embodiment, it is clear that an external mirror laser tube may be used as the laser tube, and this embodiment does not limit the present invention. .

〔Effect of the invention〕

As described above, the He-Ne gas laser device according to the present invention can suppress fluctuations in laser output caused by environmental changes such as wide-ranging changes in ambient temperature, as well as changes in laser output that occur when unnecessary force is applied to the housing. It also has the advantage of being able to easily obtain a constant output value.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of one embodiment of the present invention, Figure 2 is a He-N
It is a figure which shows the relationship between the laser output value of 632.8 om wavelength, and a solenoid current in an e-gas laser. In the figure, 1 is a laser tube, 2 is a housing, 3 is a power supply, 4 is a laser beam, 5 is a beam spiriter, 6 is a transmitted laser beam,
7 is a reflected laser beam, 8 is a light receiving element, 9 is a solenoid coil, and 1o is a control circuit. =6-

Claims (1)

[Claims] In a He-Ne gas laser device having a gas laser tube, a housing for holding the gas laser tube, and a power source, a beam splitter is provided that attaches a coil to a thin tube part of the gas laser tube to separate a part of the laser beam; A He-Ne gas laser device comprising: a light receiving element that receives laser light separated by a beam splitter; and a control circuit that controls a current flowing through a solenoid coil based on a signal from the light receiving element.