JPH0563269A - Pulse semiconductor laser-pumped solid-state laser device - Google Patents

Abstract

PURPOSE:To provide a pulse semiconductor laser pumped solid-state laser device by increasing the number of repeated pulses to increase the mean output power with a relatively simplified structure. CONSTITUTION:A pulse semiconductor laser pumped solid-state laser device includes a plurality of pumping pulse semiconductor laser apparatuses are oscillated, shifted in their oscillation timing to each other. Output pulsed laser beam L1 is yielded for each oscillation of these pumping pulse semiconductor laser devices 2, 3. Hereby, although there are employed as the pumping pulse semiconductor laser apparatuses 2, 3 ones where energy and a pulse repetition number both per one pulse area identical to those of prior art, a pulse number of pumping pulsed laser beam L0 applied to a solid laser medium 1 is made substantially plural times. Thus, the repetition pulse number of the resulting output pulsed laser L1 light is made plural times, and hence the mean output power is made plural times.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulsed semiconductor laser pumped solid-state laser device for obtaining pulsed output laser light by using pulsed laser light emitted from a pulsed semiconductor laser device as pumping light.

[0002]

2. Description of the Related Art A pulsed semiconductor laser pumped solid-state laser device that obtains pulsed output laser light by using pulsed laser light emitted from a pulsed semiconductor laser device as pumping light is described in, for example, the literature [MKReed et al., Opt. .Lett., Vo
l.13, pp204-206 1988] are known.

The device disclosed in the above document has a length of 31 m.
An Nd: YAG slab laser medium having a plate shape of m, a width of 6 mm, and a thickness of 4.6 mm, and having Brewster cut at both end surfaces was arranged in a laser resonator, and the light emitting area was 4 ×.
Average power 3.8 W at 10 mm (pulse width 200 μs,
Pulse energy 76μJ, pulse repetition number 50H
The pulsed laser light of average power 0.59 W (pulse width 150 μs, pulse energy 11.8 μJ, pulse repetition rate 50 Hz) is obtained by pumping with the two-dimensional pulsed semiconductor laser array of z). In this case, the wavelength of the pump laser light is 807 nm and the wavelength of the output laser light is 1.06 μ.
m.

[0004]

By the way, the pulsed semiconductor laser pumped solid-state laser device is often used in a laser processing device, but when a device having a larger average output power of output laser light is desired depending on the processing application. Not a few. To increase the average output power, it is necessary to increase the energy per pulse or increase the number of pulse repetitions. To this end, the average power of the pumping pulse semiconductor laser device, that is, 1
There is a need to increase the energy per pulse or the pulse repetition rate, but this has limitations. For example,
When the two-dimensional pulse semiconductor laser array is used as the excitation pulse semiconductor laser device as in the above-mentioned conventional example, the above-mentioned value is almost close to the limit.

The present invention has been made under the background described above, and a pulse semiconductor laser pumped solid-state laser capable of increasing the number of pulse repetitions and increasing the average output power with a relatively simple structure. It is intended to provide a device.

[0006]

In order to solve the above-mentioned problems, the present invention provides (1) a pulsed laser light for excitation emitted from a pulsed semiconductor laser device for excitation is arranged in a laser resonator. A pulsed semiconductor laser pumped solid-state laser device which irradiates a solid-state laser medium and excites the solid-state laser medium to obtain an output pulsed laser beam, wherein a plurality of pumping pulse semiconductor laser devices are provided, and the plurality of pumping pulses are provided. The semiconductor laser device is oscillated at mutually different oscillation timings, and output pulse laser light is obtained for each oscillation of the plurality of excitation pulse semiconductor laser devices. (2) In the pulsed semiconductor laser pumped solid-state laser device having the configuration 1, the pumping pulsed semiconductor laser device is a two-dimensional pulse laser device. It is obtained by a configuration in which characterized in that a semiconductor laser array.

[0007]

According to the above-described structure 1, a plurality of pumping pulse semiconductor laser devices are provided, and the plurality of pumping pulse semiconductor laser devices are oscillated at mutually different oscillation timings. Since the output pulsed laser light is obtained for each oscillation, even if the pulsed semiconductor laser device for excitation has the same energy per pulse and the same number of pulse repetitions as the conventional one, it can be used for excitation to the solid laser medium. The number of pulses of pulsed laser light can be substantially multiplied. Therefore, the number of repetitive pulses of the output pulsed laser light that is obtained can be increased multiple times, and eventually the average output power can be increased multiple times.

According to the configuration 2, by using a two-dimensional pulse semiconductor laser array as the excitation pulse semiconductor laser device, it is possible to obtain a stronger output pulse laser light.

[0009]

1 is a diagram showing the configuration of a pulsed semiconductor laser pumped solid-state laser device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the oscillation timing of a pumped pulsed semiconductor laser device and output pulsed laser light. .. An embodiment of the present invention will be described in detail below with reference to these drawings.
In this embodiment, a two-dimensional pulse semiconductor laser array is used as the excitation pulse semiconductor laser device.

In FIG. 1, reference numeral 1 is a solid-state laser medium,
Reference numeral 2 is a first excitation pulse semiconductor laser device, reference numeral 3 is a second excitation pulse semiconductor laser device, reference numeral 4 is a control device, reference numeral 5 is a total reflection mirror, and reference numeral 6 is an output mirror. The total reflection mirror 5 and the output mirror 6 form a laser resonator.

The solid-state laser medium 1 is an Nd: YAG slab laser medium that oscillates at a wavelength of 1.06 μm, and has a plate shape with a length of 31 mm, a width of 6 mm, and a thickness of 4.6 mm, and both end surfaces are optical axes. Brewster cut to form a predetermined angle with respect to. Front and back surfaces (hereinafter referred to as main surfaces) 1 having a large area of this solid-state laser medium 1
Reference numerals a and 1b are total reflection surfaces, and the resonant laser light is repeatedly reflected by these surfaces alternately and travels along the zigzag optical path in the solid-state laser medium 1 to enter from both end surfaces 1c and 1d. Total reflection mirror 5 that emits to form a laser resonator
And the output mirror 6 are reciprocated. In addition, the main surface 1a,
Reference numeral 1b also serves as an incident surface of the excitation laser light, and the first excitation pulse semiconductor laser device 2 and the second excitation pulse semiconductor laser device 3 are arranged at positions facing these surfaces, respectively.

Both the first excitation pulse semiconductor laser device 2 and the second excitation pulse semiconductor laser device 3 have an emission area of 4 × 10 mm and an average output power of 3.8 W (pulse width 2
This is an AlGaAs two-dimensional pulse semiconductor laser array capable of oscillating at 00 μs, pulse energy of 76 μJ, and pulse repetition rate of 50 Hz). Oscillation control of the first excitation pulse semiconductor laser device 2 and the second excitation pulse semiconductor laser device 3 is performed by the control device 4.

The control device 4 includes a first excitation pulse semiconductor laser device 2 and a second excitation pulse semiconductor laser device 3.
In addition, the pulse drive current required for pulse oscillation is alternately supplied, and both are oscillated and driven while controlling the oscillation timing of both.

The total reflection mirror 5 which constitutes one of the laser resonators is a plane mirror which totally reflects the laser light having a wavelength of 1.06 μm, and the output mirror 6 which constitutes the other of the laser resonators is A reflective film made of a dielectric multilayer film is formed on the surface of the concave surface of a glass body having a concave lens shape arranged so that the concave surface faces the laser medium 2, and the reflectance with respect to the output laser light L ₁ becomes 90%. Like this,
By setting the radius of curvature of the concave surface to 3 m, the total reflection mirror 5 constitutes a laser resonator having a resonator length of 150 mm.

In the above structure, the controller 4 drives the first pumping pulse semiconductor laser device 2 and the second pumping pulse semiconductor laser device 3 so that both the pulse width 20
The solid-state laser medium 1 was excited by alternately oscillating at 0 μs, pulse energy of 76 μJ, pulse repetition rate of 50 Hz, and average output power of 3.8 W. In this case, the mutual oscillation pulses are arranged at equal intervals between the oscillations. Since the interval t of each oscillating pulse is 20 ms, the interval of pulses by both is t / 2 = 10 ms. As a result, the output pulsed laser light L ₁ has a pulse width of 150 μm.
s, pulse energy 11.8 μJ, pulse repetition rate 100 Hz, and average power 1.18 W were obtained. This is exactly twice the average output power of the above-mentioned conventional pulse semiconductor laser pumped solid-state laser device. It should be noted that FIG. 2 is a diagram showing the above oscillation timing.

In the above-mentioned one embodiment, the Nd: YAG rod is used as the solid-state laser medium, but the solid-state laser medium includes Nd: YLF and Nd: gl.
ass, Nd: YVO ₄ , Nd: GGG, Nd: YSG
G, NYAB, NAB, Er: YAG, Er: YLF,
Er: glass or the like may be used. In that case, it is needless to say that conditions such as a laser resonator should be selected according to each laser medium.

The pulsed semiconductor laser device for pumping is also
Other than AlGaAs two-dimensional pulse semiconductor laser array,
For example, AlGaAs type, InGaAs type, AlGaI
An nP single semiconductor laser, a one-dimensional semiconductor laser array, a two-dimensional semiconductor laser array, a surface emitting semiconductor laser, or the like may be used.

Furthermore, although an example using two pumping pulse semiconductor laser devices is given, it is needless to say that by using three or more pumping semiconductor laser devices, an output pulsed laser beam having a stronger average output power can be obtained. Is.

[0019]

As described in detail above, in the semiconductor laser pumped solid-state laser device according to the present invention, a plurality of pumping pulse semiconductor laser devices are provided, and the oscillation timings of the plurality of pumping pulse semiconductor laser devices are shifted from each other. By oscillating and obtaining an output pulsed laser beam for each oscillation of the plurality of pump semiconductor laser devices for excitation, the pulse semiconductor laser device for excitation has the same energy per pulse and the same number of pulse repetitions as the conventional one. It is possible to multiply the number of pulses of the pulsed laser light for excitation to be added to the solid-state laser medium substantially even by using one, and thereby, the number of repetitive pulses of the obtained output pulsed laser light is multiplied. , It is possible to multiply the average output power by multiple times.

[Brief description of drawings]

FIG. 1 is a diagram showing the configuration of a pulsed semiconductor laser pumped solid-state laser device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of oscillation timing according to an embodiment.

[Explanation of Codes] 1 ... Solid-state laser medium, 2 ... First excitation pulse semiconductor laser device, 3 ... Second excitation pulse semiconductor laser device, 4 ...
Control device, 5 ... total reflection mirror, 6 ... output mirror.

Claims (2)

[Claims] 1. A pulsed laser light for excitation emitted from a pulsed semiconductor laser device for excitation is irradiated onto a solid-state laser medium arranged in a laser resonator, and the solid-state laser medium is excited to output pulsed laser light. In the pulsed semiconductor laser pumped solid-state laser device, a plurality of the pumped pulsed semiconductor laser devices are provided, and the plurality of pumped pulsed semiconductor laser devices are oscillated by oscillating the oscillation timings of the pumped pulsed semiconductor laser devices. A pulsed semiconductor laser pumped solid-state laser device, wherein an output pulsed laser beam is obtained for each oscillation of the semiconductor laser device. 2. The semiconductor laser pumped solid-state laser device according to claim 1, wherein the pumping pulse semiconductor laser device is a two-dimensional pulsed semiconductor laser array.