JPS6348884A - Laser resonator - Google Patents

Abstract

PURPOSE:To obtain a laser resonator, in which alignment is easy and aligning quantity can be remarkably decreased even if the attaching state of a returning mirror is changed, by constituting the returning mirror so as to have two reflecting surfaces forming a right angle. CONSTITUTION:Laser light repeats reflections between an output mirror 1 and a rear mirror 2 by way of a returning mirror 3b. Thus the laser light is amplified. Part of the light is transmitted through the output mirror 1 and taken out. Even if the returning mirror is deviated in the direction of alpha, incident light 4 and reflecting light 5 can always keep a parallel state. The reflecting light is slightly deviated by the deviation of the direction Y and the direction theta. The deviation is a parallel movement. Since the length of a light path is long, said devaition is minute and negligible in comparison with the deviation of angles. In the resonator using such a returning mirror, deformation in the direction does not affect the alignment of the laser, even if the attaching angle of the returning mirror is changed due to thermal effect and the like. Only the deformation in the direction beta is considered. Therefore, the attaching structure is simple and the change in alignment can be made small.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a laser resonator using a multiple folding method.

(Prior Art) FIG. 6 shows the configuration of a laser resonator using the multiple folding method. The laser beam is amplified by being repeatedly reflected between the output mirror 1 and the rear mirror 2, and a portion of the laser beam is transmitted through the output mirror and extracted. At this time, the degree of amplification increases as the distance between the output mirror and the rear mirror (hereinafter referred to as optical path length) increases, so it is necessary to increase the optical path length in order to obtain a large output. Therefore, by inserting a folding mirror 3a in the middle and reversing the direction of the optical path, the device a is made smaller.

(Problem to be solved by the invention) On the other hand, the output mirror and mirror must face each other accurately, and the position adjustment (mainly angle adjustment) of each mirror for this purpose is called alignment. In this case, it is naturally necessary to align the folding mirrors used for this, and this task becomes more complicated as the number of folding mirrors increases. Also, if the resonator is deformed due to temperature changes, etc.
Attaching a folding mirror causes a drop in output due to even the slightest change in angle.

The present invention is intended to solve the above-mentioned problems, and its purpose is to provide a laser resonator that is easy to align and can significantly reduce the amount of alignment required even when the state changes by attaching a folding mirror. There is a particular thing.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a laser resonator that uses folding mirrors to reverse the optical path direction of laser light and increase the optical path length, in which the folding mirrors are arranged at right angles to each other. (Function) With this configuration, the adjustment of the folding mirror becomes easy, and when the resonator is deformed due to temperature changes, the amount of alignment of the folding mirror is reduced. significantly reduced.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. In FIG. 1, a laser beam is repeatedly reflected and amplified between an output mirror 1 and a rear mirror 2 via a folding mirror 3b, and a portion of the laser beam is transmitted through the output mirror 1 and extracted. The folding mirror 3b has the function of reversing the optical path by 180°, and the resonator can be made smaller.

Referring to FIGS. 2 and 3, the relationship between incident light and reflected light of the folding mirror in this embodiment is shown.

In a conventional folding mirror, when the mirror shifts in the α direction or in the β direction, the reflected light shifts by twice as much, but with the folding mirror of this embodiment, even if it shifts in the α direction, the incident light 4 and the reflected light 5 are always parallel. can be kept. Note that in this folding mirror, the reflected light is slightly shifted due to shifts in the Y direction and the Y direction, but this shift is a parallel shift and the optical path length is long, so it is minute compared to the angular shift and can be ignored.

These relationships are shown in Table 1.

Table 1 In a resonator using such a folding mirror, even if the mounting angle of the folding mirror changes due to thermal effects, deformation in the α direction has no effect on laser alignment, and deformation in the β direction Since it is only necessary to consider the above, the installation structure is simple and changes in alignment can be reduced.

Further, even at the time of initial adjustment, it is only necessary to adjust the β direction during installation, which is less complicated than in the past.

FIG. 4 shows a laser resonator configuration as another embodiment.

This is an example in which the optical path of the laser beam is reversed twice. Also the fifth
Figures (a) and (b) show other embodiments of the folding mirror.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a laser resonator in which the alignment of the folding mirror is easy and the amount of frying required can be significantly reduced even in response to changes in the mounting state.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a laser resonator according to an embodiment of the present invention, Fig. 2 is a diagram for explaining the relationship between the folding mirror shown in Fig. 1 and the laser beam, and Fig. 3 is a diagram illustrating the relationship between the folding mirror and the laser beam. 4 is a diagram for explaining the amount of deviation of reflected light, FIG. 4 is a configuration diagram of a laser resonator according to another embodiment of the present invention, and FIG.
), (b) is a block diagram of another embodiment of the folding mirror. 1... Output mirror 2... Rear mirror 3a, 3b... Returning mirror 4... Incident light 5... Reflected light 6... Returning mirror body 7... Total reflection mirror 8... Mirror Holding agent Patent attorney Rule Ken Chika Yudo Hirofumi Mitsumata Figure 1 Figure 2 Figure 3 Figure 4 (α) (b) Figure 5

Claims (1)

[Claims] A laser resonator that uses a folding mirror to reverse the optical path direction of a laser beam and increase the optical path length, wherein the folding mirror is configured to have two reflective surfaces that are perpendicular to each other.