JPH0797672B2 - Laser optical axis adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) In a laser amplifying device in which a plurality of laser devices using metal vapor or gas as a laser medium are arranged in series as a laser amplifier and used, It relates to a device for adjusting.

(Prior Art) A laser amplifying device which uses a plurality of laser devices, one as a laser oscillator and the other as a laser amplifier to obtain a high laser output as a whole, has a configuration as shown in FIG. .

The laser oscillator 11 emits a laser beam 20 by means of a resonator including a total reflection mirror 13a and a partial reflection mirror 13b.

The laser beam 20 has its optical axis adjusted by the two total reflection mirrors 14a and 14b, enters the laser amplifier 12, and is emitted as a laser beam 21 whose laser output is increased by the amplifier. Even if the number of laser amplifiers is larger, the above configuration is repeated.

In order to maintain the maximum laser output in such a laser amplifying device, it is necessary that the optical axis of the laser beam is accurately adjusted to the geometrical axis of the laser amplifier.

However, in reality, the laser optical axis often deviates from the initial value due to vibration, thermal causes, etc.Therefore, it is necessary to readjust the total reflection mirrors 14a and 14b appropriately to align the optical axis with the normal position. Becomes

Conventionally, the method of automatically adjusting the laser optical axis has been as shown in FIG.

The reflecting mirror 15b is used as a partial reflecting mirror so that a part of the laser beam 20 is transmitted and made incident on the two-dimensional position detector 16a. The position detector 16a detects the displacement when the optical axis of the incident beam deviates from the position where it should be normal, and the control device
The angle of the reflecting mirror 15a is changed via 17a so that the laser beam 20 is adjusted to enter the normal position of the position detector 16. Similarly, the reflecting mirror 15b emits the laser amplifier 12,
Based on the deviation of the beam position transmitted through the partial reflection mirror 15c and incident on the position detector 16b, the reflection mirror 15b is passed through the control device 17b.
Adjust the angle of.

(Problems to be solved by the invention) In such a conventional configuration, since the reflecting mirrors 15b and 15c use mirrors having a reflectance of about 95% instead of 100% reflecting mirrors, the output laser beam is changed as the number of adjustment points increases There was a problem of loss.

[Structure of Invention]

(Means for Solving the Problems) The present invention relates to a copper vapor laser amplification device equipped with a laser oscillator, a laser amplifier, and a total reflection mirror for adjusting a laser optical axis from the oscillator to the amplifier. The helium neon reference laser having a different wavelength from is incident in parallel with the laser optical axis, the laser optical axis adjustment total reflection mirror to totally reflect the copper vapor laser wavelength,
A dichroic mirror is selected so that the reference laser wavelength can be partially transmitted, and the position of the reference laser that has been partially transmitted is detected by a position detector, and when the beam position shifts, the laser optical axis adjusting total reflection mirror A laser optical axis adjusting device comprising a control device for adjusting an angle.

(Operation) According to the present invention, the reflecting mirrors 2a, 2b, 2c are the laser beams 20, 21.
On the other hand, since it can be configured by a total reflection mirror, there is an effect that there is no loss of laser output from the laser amplification device.

(Example) FIG. 1 shows an example of the present invention.

The laser beam 20 from the laser oscillator 11 is reflected by the reflecting mirrors 2a, 2
After being reflected by b, it is incident on the laser amplifier 12, and the amplifier output beam 21 is reflected by the reflecting mirror 2c.

The reference laser 1 is installed outside the total reflection mirror 13a of the laser oscillator 11, and the reference laser beam 3 is passed on the central axis of the laser beam 20.

The wavelength of the reference laser beam 3 is 62 for helium-neon.
By selecting a wavelength different from the wavelength (510 nm, 578 nm) of the laser beam 20 of the laser oscillator 11 as 9 nm,
It is possible to add the following functions to the mirror existing in the laser beam.

The dichroic mirrors (dichroic mirrors) are adopted for the reflecting mirrors 13a and 13b, and the reflecting mirrors 13a and 13b function as a total reflecting mirror and a partial reflecting mirror for the laser beam 20, respectively, but those having a function of transmitting the reference laser beam 3 are selected. did.

The reflecting mirrors 2a, 2b and 2c also use dichroic mirrors and function as total reflecting mirrors for the laser beams 20 and 21, but those having a function of partially transmitting the reference laser beam 3 are selected.

As a result, the laser beam axis adjustment is performed by the reference laser beam 3
On the other hand, it is possible to perform the same method as the method described in the conventional example based on FIG.

Since the reflecting mirrors 2a, 2b, 2c can be configured as total reflecting mirrors for the laser beams 20, 21, there is no loss of laser output from the laser amplification device.

When the laser oscillator 11 and the laser amplifier 12 are copper vapor lasers (wavelength 510 nm), HeN is used as the reference laser 1.
By using a laser (wavelength 629nm),
Since they are separated by 50 nm or more, it is possible to use them for optical axis adjustment while totally reflecting the copper vapor laser beam and partially transmitting the HeNe reference laser beam.

〔The invention's effect〕

As described above, in the present invention, since the reflecting mirrors 2a, 2b, 2c can be configured by total reflecting mirrors for the laser beams 20 and 21, the effect that there is no loss of laser output from the laser amplification device is obtained. Play.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing the principle of a laser amplifier, and FIG. 3 is a block diagram showing a conventional laser optical axis adjusting device. 1 ... Reference laser, 2a, 2b, 2c ... Reflector 3 ... Reference laser beam 3 ', 3 "... Partial transmission reference laser beam 11 ... Metal vapor or gas laser oscillator 12 ... Metal vapor Or gas laser amplifier 13a, 13b …… Metal vapor or gas laser resonator mirror 14a, 14b …… Reflector, 15a …… Total reflector 15b, 15c …… Partial reflector 16a, 16b …… Two-dimensional position detector 17a, 17b ... Control device for laser beam correction

Claims (1)

[Claims] 1. A copper vapor laser amplification apparatus comprising a laser oscillator, a laser amplifier, and a total reflection mirror for adjusting the laser optical axis from the oscillator to the amplifier, for helium neon reference having a wavelength different from the copper vapor laser wavelength. A laser is incident parallel to the laser optical axis, the laser optical axis adjusting total reflection mirror is totally reflected at the copper vapor laser wavelength, and the dichroic mirror is selected so that the reference laser wavelength can be partially transmitted. A laser optical axis adjusting device comprising a controller for detecting the position of the transmitted reference laser with a position detector and adjusting the angle of the laser light axis adjusting total reflection mirror when the beam position is deviated. .