JPH10223949A - Solid-state laser oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make stable laser machining possible, by eliminating the temperature rises of mirror holders, etc., caused by leakage light from a pumping lamp. SOLUTION: A pumping lamp 9 which emits stimulating light and a laser rod 11 which makes laser oscillation by absorbing the stimulating light from the lamp 9 are housed in a pumping chamber 5. On the outside of the chamber 5, a rear mirror 13 which is faced oppositely to one end face of the rod 11 and an output mirror 15 which is faced oppositely to the other end face of the rod 11 are provided. Shielding plates 27 which shield leakage light from the chamber 5 are provided on both end sides of the chamber 5, and an optical path hole 29 is formed through each plate 27. The leakage light of the stimulating light of the pumping lamp 9 from the chamber 5 is shielded by the plates 27, and the temperature rises of the holders 17 and 19 of the mirrors 15 and 13 are prevented. Since the stimulating light passes through the optical path holes 29 of the plates 27 and resonates between the mirrors 15 and 13, a laser beam LB is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state laser oscillation device, and more particularly to a solid-state laser oscillation device capable of preventing a temperature rise of a mirror holder or the like due to leakage light of an excitation lamp.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2 and FIG.
The pumping chamber 103 includes a plurality of excitation lamps 105 for irradiating excitation light with a voltage from a power supply (not shown), and a plurality of excitation lamps 1.
A laser rod 107 containing a laser medium made of a solid material for absorbing the excitation light from the laser beam 107 is stored.

[0003] At the outside on both sides of the pumping chamber 103, a rear mirror 109 facing one end face of the laser rod 107 and an output mirror 111 facing the other end face of the laser rod 107 are provided. The rear mirror 109 and the output mirror 111 are supported by mirror holders 113 and 115, respectively. Further, a shutter 117 for blocking the laser beam LB is provided in front of the laser beam LB oscillated from the output mirror 111 for safety.

[0004]

Incidentally, in the conventional solid-state laser oscillation device 101, the pumping chamber 103 is usually made of an acrylic plate,
With the flash of No. 5, a wide range of wavelengths from visible light to ultraviolet light comes out of the pumping chamber 103.

For this purpose, the leakage light of the excitation lamp 105 is transmitted to the output mirror 111 as shown by the dotted lines in FIGS.
And mirror holders 113 and 115 of the rear mirror 109
, Causing the beam mode to change.

Incidentally, in the case of a solid-state laser, the laser medium (rod) generates heat due to optical excitation and an internal temperature difference due to heat dissipation to the surroundings, so that a thermal lens effect occurs.
A hemispherical optical resonator such as a gas laser cannot be used, and a laser rod originally has poor homogeneity as compared with a gas, and thus tends to have multiple transverse modes.

The laser rod 107 and the output mirror 1
When the distance between the lens 11 and the rear mirror 109 is increased,
As shown in FIG. 4, there is a problem that an unstable output region A is likely to appear due to the thermal lens effect, which adversely affects laser processing performance.

Further, when exchanging the excitation lamp 105, the pumping chamber 103 must be opened. At that time, since dust and the like from the outside air easily adhere to the end face of the laser rod 107, there is a problem that the laser output and the beam mode are reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to eliminate a rise in the temperature of a mirror holder or the like due to leakage light of an excitation lamp and perform stable laser processing. An object of the present invention is to provide a solid-state laser oscillation device.

[0010]

According to a first aspect of the present invention, there is provided a solid-state laser oscillating device for irradiating an excitation light with a voltage from a power supply, and an excitation light from the excitation lamp. A laser rod containing a laser medium made of a solid material for absorbing and oscillating a laser is housed in a pumping chamber.Outside on both sides of the pumping chamber, a rear mirror opposed to one end surface of the laser rod and the In a solid-state laser oscillation device provided with an output mirror facing the other end surface of a laser rod, leakage of excitation light in the pumping chamber is provided between the pumping chamber and the rear mirror and between the pumping chamber and the output mirror. A shielding plate for shielding light is provided, and a laser beam excited by the laser rod is provided on each shielding plate. Beam is characterized in that is provided with an optical path hole passing through.

Therefore, since the leakage light of the excitation light of the excitation lamp from the pumping chamber is shielded by the shielding plate, the temperature rise of the rear mirror holder and the output mirror holder is prevented, and the positions of the output mirror and the rear mirror are stabilized. Therefore, a stable laser beam can be obtained.

According to a second aspect of the present invention, there is provided the solid-state laser oscillation device according to the first aspect.
The laser rod is characterized in that both end surfaces of the laser rod and the optical path holes of the respective shield plates are connected by a beam cover having a through hole through which a laser beam can pass.

Therefore, when exchanging the excitation lamp, the pumping chamber is opened. However, since the space between both end faces of the laser rod and the optical path holes of the respective shield plates is protected by the beam cover, the pump rod is opened at the end face of the laser rod. Makes it harder for outside dust to adhere, and the laser output and beam mode are stable.
Stable laser processing can be obtained. Further, the life of the laser rod can be extended.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the solid-state laser oscillation device of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, for example, a YAG laser oscillating device 1 as a solid-state laser oscillating device according to the present embodiment includes a base 3 and a pumping chamber 5 provided on the base 3 in a YAG laser oscillating device. A plurality of excitation lamps 9 for irradiating excitation light with a high voltage from a power supply 7 and a YAG rod 11 (laser rod) that absorbs the excitation light from the plurality of excitation lamps 9 and oscillates laser.

The YAG rod 11 contains a laser medium made of a solid material for absorbing the excitation light from the excitation lamp 9 and oscillating the laser. This laser medium is YA
Nd in which neodymium ion (Nd2 +) is mixed as an active substance into a host crystal of G (Yttrium Alminium Garnet)
-YAG.

The end surface of the YAG rod 11 is usually machined into a plane perpendicular to the optical axis, and the surface accuracy of the end surface is λ /
Polished to about 10 and an anti-reflection film is deposited. However, there are also rods whose end faces are cut obliquely and rods which are processed and polished into a concave shape, and are not particularly limited.

The excitation lamp 9 is a straight discharge tube mainly filled with Xe or Kr gas, but there is also a spiral discharge tube, and there is no particular limitation.

Outside the pumping chamber 5, a rear mirror 13 facing one end of the YAG rod 11 and an output mirror 15 facing the other end of the YAG rod 11 are respectively provided on the base 3 with a mirror holder. 1
The mirror holders 17 and 19 are fixed on the base 3. Although the output mirror 15 and the rear mirror 13 are plane mirrors in the example of the present embodiment, a concave mirror and sometimes a convex mirror can be used, and there is no particular limitation.

The YAG rod 11 is a four-level laser transition, and when irradiated with excitation light from an excitation lamp 9, the YAG rod 11 absorbs light having a wavelength of 500 to 900 nm and is excited to an excitation level. This excited level quickly shifts to a lower level because its lifetime is short. The life of this level is about 300μsec
Since the lifetime of the lower level is as short as 1 nsec, population inversion is obtained between these two energy levels, and laser transition occurs.

The pumping light pumped by the YAG rod 11 resonates between the output mirror 15 and the rear mirror 13 to generate a standing wave, which passes through the output mirror 15 and is oscillated by a laser. .

On the base 3, a shutter 21 is provided in front of the optical path of the laser beam LB of the output mirror 15, and this shutter 21 is provided for safety when it is necessary to shut off laser oscillation. It is a device provided in.

On the base 3, an output mirror cover 23 which covers the output mirror 15 and a shutter 21 which are supported by a mirror holder 19 for dustproofing and safety.
And a rear mirror cover 25 that entirely covers the rear mirror 13 supported by the mirror holder 17. The output mirror cover 23 and the rear mirror cover 25 are made of a metal plate or the like.

The wall surface of the rear mirror cover 25 on the pumping chamber 5 side and the wall surface of the output mirror cover 23 on the pumping chamber 5 side shield the leakage light of the excitation light from the excitation lamp 9 in the pumping chamber 5. The shielding plate 27 is provided with a laser beam LB oscillated by the YAG rod 11.
An optical path hole 29 through which the light passes is provided.

Therefore, even if the excitation light from the excitation lamp 9 leaks from the pumping chamber 5, the mirror holders 17 and 19 are not heated because they are shielded by the shielding plate 27. Temperature rise is prevented, and the positions of the output mirror 15 and the rear mirror 13 are stabilized. As a result, a stable laser beam LB is obtained.

Further, a space between the both end surfaces of the YAG rod 11 and the optical path hole 29 of the shielding plate 27 is preferably sealed by a beam cover 33 having a through hole 31 through which a laser beam LB can pass. Are linked together.

Therefore, when replacing the excitation lamp 9 with a new excitation lamp 9, the pumping chamber 5 is opened, but the space between both end surfaces of the YAG rod 11 and the optical path hole 29 of the shielding plate 27 is protected by the beam cover 33. Has been
External dust and the like hardly adhere to the end surface of the YAG rod 11. As a result, the laser output and the beam mode are stabilized.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes. In the present embodiment, a YAG laser oscillation device has been described as an example of a solid-state laser oscillation device, but a ruby laser oscillation device and other solid-state laser oscillation devices may be used.

For example, a ruby laser oscillation device has a ruby rod (laser rod) in which an artificial ruby crystal is formed into a columnar shape and whose both end surfaces are polished, an Xe lamp for excitation (excitation lamp 9), and an optical resonator (output) of a plane mirror. (A mirror and a rear mirror), and a lamp power supply for supplying a high voltage to the excitation lamp. Other components are the same as those of the above-described YAG laser oscillation device.

[0030]

As will be understood from the embodiments of the invention as described above, according to the first aspect of the present invention, the leakage light of the excitation light of the excitation lamp from the pumping chamber is shielded by the shielding plate. In addition, it is possible to prevent the temperature of each rear mirror holder and output mirror holder from rising. Therefore, the positions of the output mirror and the rear mirror are stabilized, so that a stable laser beam can be obtained.

According to the second aspect of the present invention, the pumping chamber is opened each time the excitation lamp is replaced. However, since the space between both end faces of the laser rod and the optical path hole of the shielding plate is protected by the beam cover, External dust and the like hardly adhere to the end surface of the laser rod. As a result, the life of the laser rod can be extended, the laser output and the beam mode can be stabilized, and stable laser processing can be performed.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is a schematic front view including a cross section of a main part of a solid-state laser transmission device.

FIG. 2 is a schematic front view showing a conventional example, including a cross section of a main part of a solid-state laser transmission device.

FIG. 3 is a plan view of FIG. 2;

FIG. 4 is a graph showing the relationship between the laser output and the injected power in the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 YAG laser oscillation device (solid-state laser oscillation device) 5 Pumping chamber 9 Excitation lamp 11 YAG rod (laser rod) 13 Rear mirror 15 Output mirror 17 Mirror holder 19 Mirror holder 23 Output mirror cover 25 Rear mirror cover 27 Shielding plate 29 Optical path hole 31 Penetration Hole 33 Beam cover

Claims (2)

[Claims] An pump lamp for irradiating an excitation light with a voltage from a power supply and a laser rod containing a laser medium made of a solid material for absorbing the excitation light from the excitation lamp and performing laser oscillation. A solid state laser oscillation device housed in a chamber and provided on the outside on both sides of the pumping chamber with a rear mirror facing one end face of the laser rod and an output mirror facing the other end face of the laser rod; And a rear mirror and between the pumping chamber and the output mirror, a shielding plate is provided for shielding leakage light of the excitation light in the pumping chamber, and a laser beam excited by the laser rod is provided on each shielding plate. A solid-state laser oscillation device comprising an optical path hole that passes therethrough. 2. The method according to claim 1, wherein the laser rod is connected between both end faces thereof and the optical path holes of the respective shield plates by a beam cover having a through hole through which a laser beam can pass. The solid-state laser oscillation device according to claim 1.