JP2001111149A - Solid laser device and measuring device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology of oscillating a high output by a laser oscillator using a laser medium obtained by doping ions as a 3-level laser. SOLUTION: Excited lights squeezed by a lens are incident on an end face of Tm: YAG rods 3, 3a from a different direction from a laser optical axis. When the end faces of the Tm: YAG rods 3, 3a are formed vertically to the laser optical axis, LD bars 9a to 9d are installed vertically to a plane made by an optical axis of the laser optical axis and the excited light from the LD bars 9a to 9d. Furthermore, when the end faces of the Tm: YAG rods 3, 3a are formed at an arbitrary angle to the laser optical axis, the LD bars 9a to 9d are installed in parallel to a plane made by the laser optical axis and a perpendicular line of a laser medium end face.

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 pumped by a semiconductor laser, which has high efficiency and excellent environmental resistance, and a measuring apparatus using the laser light.

[0002]

2. Description of the Related Art A laser medium used for a laser called a so-called three-level laser such as Er, Ho and Tm is:
It shows absorption characteristics for the oscillation wavelength. Therefore, in order to improve the oscillation efficiency of a laser oscillator equipped with a YAG rod (an example of a solid-state laser medium) doped with these ions, it is indispensable to reduce the absorption with respect to the oscillation wavelength.

FIGS. 10 (a) and 10 (b) are schematic diagrams of a laser oscillator using a YAG rod which is usually doped with these three-level ions. FIG. 10A is a front view, and FIG. 10B is a side view.

This laser oscillator is side-pumped,
The outer diameter of the G rod 33 is several mm. The YAG rod 33 is provided in a flow tube 35 through which a cooling water 34 circulates. Outside the flow tube 35, laser diodes (hereinafter, referred to as LDs) 36a to 36d, which are semiconductor lasers that emit excitation light at an angle of 90 degrees, are provided in parallel with the YAG rod 33.

Since the YAG rod 33 is used by side-pumping the laser medium here, the non-pumped portion 37 is used.
Those not doped with ions are joined to a and 37b. This is because it is necessary to increase the ion concentration in order to favorably absorb the excitation light from the LDs 36a to 36d. On the other hand, as the ion concentration increases, the absorption increases, but the absorption loss also increases. In particular, the absorption loss in the non-excited part is large. Therefore, the non-excited portions 37a and 37b are diffusion-bonded to those not doped with ions to reduce the absorption loss of the YAG rod 33.

On the other hand, in the case of end-face excitation, as shown in FIG. 11, YAG doped with ions serving as a three-level laser is used.
Since the absorption length can be increased in the optical axis direction of the rod 33a, a decrease in the excitation efficiency can be prevented even if the ion concentration is reduced. In this case, the excitation LD light from the LD 36e is transmitted to the YAG rod 33a.
Since it is necessary to condense the light on the end face, a lens duct 38 is provided between the LD 36e and the YAG rod 33a to condense light having a square cross section. Further, a mirror coating is applied to the end surface of the YAG rod 33a to provide a mirror 39.
Used as Note that a mirror 40 for a resonator is provided on the other end surface side of the YAG rod 33a.

[0007]

However, in the case of the above-described side-surface excitation, the ion-doped YAG rod and the undoped YAG rod are joined by diffusion bonding, so that both boundary surfaces serving as the junction are formed. It is necessary to perform mirror finishing, and its production requires high cost. Moreover,
In the case of low-order mode oscillation, matching between the excitation distribution and the oscillation beam profile is poor.

Further, in the case of the above-described end-face pumping, the output of the pumping light easily oscillates up to a level of several W, so that pumping with good matching with the beam is possible. It is difficult to output.

In order to increase the output power, it is difficult to focus the excitation light on the end face of the laser medium with a 1 cm bar LD in which the emission points for emitting the excitation light are arranged in a line. Must be used. If a high-power LD bar formed by assembling LDs is used, the coating of the condensing optical system and the laser medium becomes special, so that an increase in cost is inevitable.

Further, since the excitation light is incident and excited from the direction coaxial with the laser optical axis, it is difficult to install a mirror constituting the resonator, and it is necessary to perform a special treatment on the end face of the laser medium and use it as a mirror. is there.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and is a laser oscillator using a YAG rod doped with ions to be a three-level laser. It aims to provide technologies that can perform analysis and analysis.

[0012]

According to a first aspect of the present invention, there is provided a semiconductor laser as a pumping means and a pair of reflecting mirrors disposed on the optical axis of laser oscillation with a solid-state laser medium interposed therebetween. In the solid-state laser device, the excitation light from the semiconductor laser is incident from an end face of the solid-state laser medium at a predetermined angle with respect to the optical axis of the laser oscillation, and the solid-state laser medium Is a solid-state laser device characterized in that both end faces are inclined parallel to each other at a predetermined angle with respect to the optical axis of the laser oscillation.

According to the second aspect of the present invention,
In a solid-state laser device formed of a pair of reflecting mirrors and a semiconductor laser serving as an excitation unit, which are disposed on the optical axis of laser oscillation so as to sandwich the solid-state laser medium, excitation light from the semiconductor laser is: A solid-state laser, which is incident at an angle from the end face of the solid-state laser medium with respect to the optical axis, and wherein the optical axis of the excitation light and the optical axis of the laser oscillation form a Brewster angle. Device.

According to the third aspect of the present invention,
The solid-state laser medium is a solid-state laser device, wherein a side surface of the medium is coated with a coating for reflecting the excitation light.

According to a fourth aspect of the present invention,
The solid-state laser medium is a solid-state laser device, wherein a side surface of the medium is bonded to a metal heat sink over the entire circumference.

According to the fifth aspect of the present invention,
The solid-state laser device described above, and a light-receiving unit that receives light reflected, scattered, or transmitted by the object to be measured by the laser light emitted from the solid-state laser device, and performs measurement based on the result of the light reception. A measuring device for performing measurement on an object.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an LD showing an embodiment of the present invention.
It is a schematic block diagram of an excitation solid-state laser oscillation device. FIGS. 2A and 2B are schematic structural views of an LD pumping module constituting a part of the LD pumped solid-state laser oscillation device. FIG. 2A is a front view and FIG. ) Is a side view thereof. That is, the LD excitation module 2 is provided so as to sandwich the pair of resonator mirrors 1a and 1b provided on the optical axis.

The LD excitation module 2 is provided with a Tm: YAG rod 3 as a solid-state laser medium on the optical axis.
The end surface of the Tm: YAG rod 3 is cut such that the perpendicular to the end surface is at a Brewster angle with respect to the central axis (optical axis) of the rod, and both end surfaces are parallel to each other. Also, T
The outer peripheral surface of the m: YAG rod 3 is provided with a reflective coating 4 of Au, Ag, or Cu so as to reflect the excitation light into the Tm: YAG rod 3.

The Tm: YAG rod 3 is entirely set in a metal heat sink 5. The heat sink 5 is connected to the radiation fins 11 via the heat pipe 6, and the temperature of the heat sink 5 is controlled by a temperature controller (not shown).

Therefore, the heat generated in the Tm: YAG rod 3 is conducted to the metal heat sink 5 adhered to the entire periphery of the side surface of the Tm: YAG rod 3, and is further transported to the radiation fins by the heat pipe 6. , Tm: YAG rod 3 is always maintained at a predetermined temperature.

Further, the Tm: YAG rod 3 is mounted on a shaft provided in a direction perpendicular to both end surfaces of the Tm: YAG rod 3.
In order from the side, spherical lenses 7a and 7b, cylindrical lenses 8a and 8b, and an LD bar 9 having a length of about 1 cm.
a and 9b are provided respectively. In addition, these spherical lenses 7a and 7b and cylindrical lenses 8a and 8b
The set of the LD bars 9a and 9b having a length of about 1 cm is not always required to be provided on both end faces of the Tm: YAG rod 3, and if only one has sufficient output, it may be provided on only one.

The LD bars 9a and 9b having a length of about 1 cm
Are provided with light-emitting points 10a, 10b,... Arranged in a straight line as shown in FIG.
a and 10b are long (about 100 μm) in the direction parallel to the LD bars 9a and 9b and short (about 1 μm) in the vertical direction. Therefore, the divergence angle of the excitation light emitted from the LD bars 9a, 9b is 10 degrees with respect to the direction parallel to the LD bars 9a, 9b.
The degree is about 35 degrees, and the characteristic is about 35 degrees in the vertical direction. The LD bars 9a and 9b are connected to an LD driver 12 to control light emission of the LD.

The LD bars 9a, 9b are provided by the cylindrical lenses 8a, 8b installed in parallel with the LD bars 9a, 9b.
The component of the excitation light in the vertical direction having a large divergence angle emitted from 9b is collimated (spread angle adjustment). Next, the excitation light is collected by the spherical lenses 7a and 7b. FIG.
In the case of the present embodiment shown in (a) and (b), spherical lenses 7a and 7b having a focal length f = 10 mm are used.

As shown in FIG. 4A, the LD bar 9a,
The components of the excitation light in the direction parallel to 9b are spherical lenses 7a,
7b, the light is condensed by only a plurality of light emitting points 10a, 10b
.., The converging diameter is about 3 mm on the end surface of the Tm: YAG rod 3 due to the wavefront aberration. On the other hand, FIG.
As shown in the figure, the divergence angle of the excitation light component in the direction perpendicular to the LD bars 9a and 9b is adjusted to about 9 degrees by a rod lens having a diameter of 5 mm, and Tm: YAG is adjusted by the spherical lenses 7a and 7b.
The light is focused to about 1.5 mm on the end face of the rod 3.

Therefore, the Tm: YAG rod 3 has an elliptical shape with a major axis of 3 mm and a minor axis of 15 mm on the end surface. When viewed from the center axis of the Tm: YAG rod 3, the diameter is 1 mm.
It becomes a 5 mm circle. The excitation light incident on the Tm: YAG rod 3 propagates through the Tm: YAG rod 3 while being reflected by the side surface of the Tm: YAG rod 3 and is absorbed. Excitation light incident at an incident angle of 19 degrees with respect to the perpendicular to the end face changes its angle to about 10 degrees with respect to the perpendicular to the end face by refraction, and transmits through the end face. 61.10 = 5 with respect to the laser optical axis
The angle is one degree.

Here, as shown in FIG. 5, the radius of the incident beam is ω, Tm: the radius of the YAG rod 3 is r, and Tm:
The angle between the perpendicular of the end face of the YAG rod 3 and the laser optical axis is θ,
Assuming that the incident angle and the transmission angle of the excitation light are ηn and φ, the excitation light (beam diameter 2
ω) does not re-enter the end face and is reflected at the side face,
The following conditions are satisfied for the diameter of the m: YAG rod 3 and the beam diameter of the excitation light at the end face of the Tm: YAG rod 3. Note that the spread of the excitation light is ignored.

(Equation 1) Further, the following relationship holds between the incident angle η and the transmission angle の of the excitation light.

N1 · sin η = n2 · sinψ (2) where n1: incident side refractive index (= 1), n2: laser medium refractive index (= 1.82).

In the case of the present embodiment, equation (1) indicates that r ≧ 2
ω, and the diameter of the Tm: YAG rod 3 is φ6 mm (r =
3 mm) or more, the excitation light is almost Tm: YAG
The light propagates through the rod 3 and is efficiently excited.

When the excitation light propagates through the Tm: YAG rod 3, the side surface is circular, so that the excitation light always propagates through the same optical path as viewed from the laser optical axis. That is, each time the incident excitation light is reflected on the side surface, the excitation light passes through the position (range) first condensed on the end face, as viewed from the laser optical axis direction, so that the excitation distribution is near the center of the Tm: YAG rod 3. It shows a characteristic having a peak. Therefore, excitation matching with an oscillation beam having a Gaussian profile seen in low-order mode oscillation or the like is performed.

Although the LD bars 9a and 9b are used one by one, efficient excitation can be achieved by using a stacked LD (not shown) in which the LD bars 9a and 9b are stacked as necessary. Become.

Tm: YAG which is an excited laser medium
The rod 3 oscillates with two resonator mirrors 1a and 1b provided with the Tm: YAG rod 3 interposed therebetween. At this time, since the end face of the Tm: YAG rod 3 is cut to the size of the Brewster angle, oscillating light with linearly polarized light is obtained.

Next, a modification of the above embodiment will be described. The basic configuration itself of the LD-pumped solid-state laser device is the same as that shown in FIG. 1, but the internal configuration of the LD-pumped module constituting a part of the LD-pumped solid-state laser device is different.

FIGS. 6A and 6B are schematic structural views of the LD excitation module, and FIG. 6A is a front view of FIG.
(B) is a side view thereof. That is, the LD excitation module 2a is provided with a pair of resonator mirrors (not shown) provided on the optical axis.

The LD excitation module 2a has T on the optical axis.
An m: YAG rod 3a is provided, and both end surfaces of the Tm: YAG rod 3a are cut in a direction perpendicular to the optical axis. Further, the excitation light is applied to the outer peripheral surface of the Tm: YAG rod 3a.
A reflection coating 4a of Au, Ag, Cu, or the like is applied so as to reflect the light into the YAG rod 3a.

The entire Tm: YAG rod 3a is installed in a metal heat sink 5a. The heat sink 5a is connected to the radiating fins 11a via a heat pipe 6a, and the temperature of the heat sink 5a is controlled by a temperature controller (not shown).

Therefore, the heat generated in the Tm: YAG rod 3a is thermally conducted to the metal heat sink 5a adhered to the entire periphery of the side surface of the Tm: YAG rod 3a, and is further transported to the radiation fins by the heat pipe 6a. Tm: Y
The AG rod 3a is always maintained at a predetermined temperature.

Further, Tm: Tm is located on the optical axis at both end surfaces of the YAG rod 3a at a predetermined angle (Brewster angle).
m: spherical lenses 7c, 7 sequentially from the YAG rod 3a side
d, cylindrical lenses 8c and 8d and length 1c
About m LD bars 9c and 9d are provided, respectively. The set of the spherical lenses 7c and 7d, the cylindrical lenses 8c and 8d, and the LD bars 9c and 9d having a length of about 1 cm does not necessarily need to be provided on both end surfaces of the Tm: YAG rod 3a. If it is sufficient, it may be installed on only one side.

The LD bars 9c and 9d having a length of about 1 cm
Are provided with light-emitting points 10a, 10b,... Arranged in a straight line as shown in FIG.
are long in the direction parallel to the LD bars 9c and 9d (about 100 μm) and short in the vertical direction (about 1 μm). Therefore, the divergence angle of the excitation light emitted from the LD bars 9c and 9d is 1 in the direction parallel to the LD bars 9c and 9d.
At about 0 degree, the characteristic is different from about 3a5 degree in the vertical direction. The LD bars 9c and 9d are connected to an LD driver 12 to control the light emission of the LD.

The LD bars 9c, 9d are provided by the cylindrical lenses 8c, 8d installed in parallel with the LD bars 9c, 9d.
The component of the excitation light in the vertical direction having a large divergence angle emitted from 9d is collimated (spread angle adjustment). Next, the excitation light is collected by the spherical lenses 7c and 7d. As shown in FIGS. 4A and 4B, in the case of the present embodiment, spherical lenses 7c and 7d having a focal length f = 10 mm are used.

As shown in FIG. 4A, the LD bar 9c,
The component of the excitation light in the direction parallel to 9d is a spherical lens 7c,
Although the light is condensed only at 7d, a plurality of light emitting points 10a, 10b
.., Tm: YAG due to wavefront aberration
On the end surface of the rod 3a, the condensing diameter is about 3 mm. on the other hand,
As shown in FIG. 4B, the divergence angle of the excitation light component in the direction perpendicular to the LD bars 9c and 9d is adjusted to about 9 degrees by a rod lens having a diameter of 5 mm, and the sphericity of the spherical lenses 7c and 7d.
m: Focused on about 1.5 mm on the end surface of the YAG rod 3a.

Accordingly, on the end surface of the Tm: YAG rod 3a, the rod has an elliptical shape with a major axis of 3 mm and a minor axis of 15 mm.
When viewed from the center axis of the Tm: YAG rod 3a, it becomes a circle having a diameter of 15 mm. Excitation light that has entered the Tm: YAG rod 3a propagates through the Tm: YAG rod 3a and is absorbed while being reflected by the side surface of the Tm: YAG rod 3a. Excitation light incident at an incident angle of 19 degrees with respect to the perpendicular to the end face changes its angle to about 10 degrees with respect to the perpendicular to the end face by refraction, and transmits through the end face. 6 for laser beam axis
1.10 = 51 degrees.

Therefore, similar to the above embodiment,
The excitation light that is the excitation light by the LD bars 9c and 9d is T
m: 15 m in diameter when viewed from the center axis of the YAG rod 3a
m. The excitation light that has entered the Tm: YAG rod 3a propagates through the Tm: YAG rod 3a and is absorbed while being reflected on the side surface of the Tm: YAG rod 3a. Therefore, the excited laser medium is provided with the laser medium interposed therebetween. Laser oscillation occurs in the two resonator mirrors 1a and 1b thus obtained,
At that time, since the optical axis of the Tm: YAG rod 3a and the optical axis of the excitation light are set to form a Brewster angle, oscillation light with linearly polarized light is obtained.

As described in the above embodiments, in the LD bar used in the present invention, a plurality of light emitting points for emitting excitation light are provided in a bar having a length of about 1 cm in a straight line. . Therefore, when light is condensed by a spherical lens, the pattern shape at the light condensing point is an ellipse whose major axis is the direction of the bar. Therefore, when the end face of the laser medium is formed perpendicular to the laser optical axis, by installing the LD bar perpendicular to the plane formed by the laser optical axis and the excitation optical axis, the LD bar is viewed from the laser optical axis direction. The profile on the end face of the laser medium becomes circular, and efficient excitation matching the shape (mode) of the oscillation beam can be obtained.

The excitation light incident on the Tm: YAG rod propagates through the Tm: YAG rod while being reflected by the reflection surface coated on the side surface, so that it is efficiently absorbed even if the ion doping amount is reduced. Is done.

When the end face of the Tm: YAG rod is formed at an arbitrary angle with respect to the laser optical axis, the LD bar is set in parallel with the plane formed by the laser optical axis and the perpendicular to the laser medium end face. As a result, an elliptical condensing profile is formed on the end face of the Tm: YAG rod, and the profile viewed from the laser optical axis direction is circular, so that efficient excitation matching the shape (mode) of the oscillation beam can be obtained.

As described above, it is possible to obtain excitation with good matching with the oscillation beam without using a special optical system, and since the laser optical axis and the excitation optical axis are not coaxial,
A normal mirror or the like can be used. In other words, it is possible to excite the oscillation beam with good matching properties, and to obtain a laser beam with high efficiency and high output even without a special optical system or coating.

The cooling of the Tm: YAG rod is
m: Since it can be cooled by heat conduction to a solid using the entire circumference of the side surface of the YAG rod, it can be used for lasers mounted on airplanes and satellites that have severe operating environment conditions, and is a measurement device that performs outdoor measurements. In this case, good measurement can always be performed without being affected by the measurement environment. They are widely applicable to commonly used measurements, for example,
It is a measurement of distance, wind speed, or particle distribution in the atmosphere.

Since each measuring method is a commonly used laser measuring method, its outline will be described.
When the distance is measured, this laser measuring method is performed by measuring Δt as shown in FIG. In other words, based on the time until the laser light emitted (transmitted) from the above-described LD-excited solid-state laser device is reflected or scattered in the measured object and returns (receives),
The measurement of the object to be measured is performed.

FIG. 8 shows a configuration diagram of a distance measuring system using the solid-state laser of the present invention.

The laser transmitter 14 includes the above-described LD pumped solid-state laser device 21 and the laser power source 2 for supplying power thereto.
2, and a transmission circuit unit 23 for controlling the power supply is provided. A part of the laser light emitted from the LD-pumped solid-state laser device 21 is transmitted through the mirror 20 to the optical sensor A2.
4 and the rest is emitted to a target (object to be measured) 25. The reflected (scattered) light from the target 25 is received by the optical sensor B18 via the receiving optical system 26 and the filter 19 of the control system 29. The gain of the received light signal obtained by the optical sensor B18 is controlled by the preamplifier 27 and the receiving circuit unit 28, and amplification is performed (these signals correspond to the control system 29). Distance measurement is performed based on the difference between the light receiving times of the optical sensor A24 and the optical sensor B18.

The actual distance measurement is performed as follows. LD
The excitation solid-state laser is pulse-oscillated and irradiated to a target whose distance is to be measured. The reflected (scattered) light from the target is received. The apparatus is provided with a detector that detects a part of the laser light when transmitting the laser, and a detector that receives the reflected light. The detected transmission optical signal has a time difference Δt from the reception optical signal.
And the distance L can be obtained by the following equation.

L = c × Δt / 2 where c is the speed of light.

Next, FIG. 9 shows the configuration of a speed measuring system using the fixed laser device of the present invention. The functions of the components denoted by the same reference numerals as those in FIG. 8 are the same. A part of the laser light emitted from the LD pumped solid-state laser 21 is reflected by the mirrors 20a and 20b and is reflected by the optical sensor C24.
c, and the rest is emitted to the target (measured object) 25 at the frequency f. The reflected (scattered) light from the target 25 is received by the receiving optical system 2 at a frequency f + Δf (Hz).
6. The optical sensor C2 via the filter 19 and the mirror 20b
4c. The frequency distribution of the received signal obtained by the optical sensor C24c is analyzed by the spectrum analyzer 31, and the gain is controlled by the receiving circuit unit 28 (these correspond to the control system 29a). The speed of the target 25 can be measured from the frequency difference Δf (Hz) obtained by the optical sensor C24c.

The actual measurement is performed as follows. LD
The laser light obtained by continuously oscillating the excited solid-state laser is divided into two parts, and one of them is irradiated to a target whose air velocity or the like (wind velocity in the case of air) is to be measured. The reflected light from the target is received, summed with the other transmitted light divided into two, and incident on the photodetector. If the target has a speed relative to the laser device, the received light undergoes a frequency shift due to the Doppler effect. This is so-called interference. By measuring the frequency difference Δf (Hz) with a spectrum meter, the relative speed of the target can be measured.

Similarly, by changing the light receiving optical system, the target is irradiated with laser light, transmitted light and reflected light are detected, and the concentration of molecules existing in the optical path and absorbing at the laser light wavelength is measured. You can also.

The measurement of the distance and the object as described above is often performed outdoors, and the measurement system can be easily configured by using the solid-state laser device of the present invention.

In each of the above embodiments, a rod-shaped Tm: YAG having a diameter of φ6 mm is used as the solid-state laser medium.
However, the present invention does not depend on the material, shape, and size of the laser medium, and the same effect can be obtained as long as laser oscillation can be performed even with a laser medium having a polygonal cross section (including a slab laser).

In the first embodiment, the end face of the Tm: YAG rod of the laser medium is cut at the Brewster angle, but an end face is formed in which the excitation light is efficiently incident and there is no loss with respect to the laser light. The same effect can be obtained.

Further, a rod lens having a diameter of φ5 mm and a spherical lens having a focal length of f10 mm are used for the focusing system of the excitation light, but if it can be focused in a shape matching the laser beam profile when viewed from the laser optical axis direction. The same effect can be obtained regardless of the configuration, size and arrangement of the condensing optical system, and can be arbitrarily selected.

Further, the LD bar and the Tm: YAG rod are heat-transported using a heat pipe for cooling, and finally the air cooling system is used. However, if the cooling can be performed without affecting the laser performance, the cooling system or the cooling system may be used. The same effect is obtained regardless of the medium.

The LD bar used for excitation was 1 cm
One bar is mounted, and excitation is performed from both end faces. However, the same effect can be obtained even when an LD in which a plurality of 1 cm bars are stacked is used as long as the basic configuration is the same.

[0063]

According to the present invention, a laser oscillator using a laser medium doped with ions to become a three-level laser is provided.
It became possible to oscillate at high output.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an LD-pumped solid-state laser oscillation device according to an embodiment of the present invention.

FIG. 2 (a) is a schematic front view of an LD excitation module,
(B) is the side view.

FIG. 3 is a perspective view of an LD bar.

FIGS. 4A and 4B are diagrams illustrating the spread of light emitted from an LD. FIGS.

FIG. 5 is a diagram illustrating a cross-sectional shape of the excitation light along the optical axis of the laser.

FIG. 6A is a schematic front view of a modification of the LD excitation module, and FIG. 6B is a side view thereof.

FIG. 7 is a schematic diagram of a signal illustrating a principle of distance measurement in the measuring device according to the embodiment of the present invention.

FIG. 8 is a schematic configuration diagram of a distance measuring system according to an embodiment of the present invention.

FIG. 9 is a schematic configuration diagram of a speed measurement system according to an embodiment of the present invention.

FIG. 10 is a schematic view of a conventional side-pumped laser oscillation device.

FIG. 11 is a schematic view of a conventional end-pumped laser oscillation device.

[Explanation of symbols]

1a, 1b: resonator mirror, 2, 2a: LD excitation module, 3, 3a: Tm: YAG rod, 7a to 7d: spherical lens, 8a to 8d: cylindrical lens, 9a to 9a
9d: LD bar, 10a, 10b ...: light emitting point

Claims (5)

[Claims] 1. A solid-state laser device comprising: a pair of reflecting mirrors disposed on an optical axis of laser oscillation with a solid-state laser medium interposed therebetween; and a semiconductor laser serving as an excitation unit. Excitation light is incident at an angle from the end face of the solid-state laser medium with respect to the optical axis of the laser oscillation, and the solid-state laser medium has both end faces with respect to the optical axis of the laser oscillation. A solid-state laser device which is inclined parallel to each other at a predetermined angle. 2. A solid-state laser device comprising: a pair of reflection mirrors disposed on an optical axis of laser oscillation with a solid-state laser medium interposed therebetween; and a semiconductor laser serving as an excitation unit. Excitation light is incident at an angle from the end face of the solid-state laser medium with respect to the optical axis, and that the optical axis of the excitation light and the optical axis of the laser oscillation form a Brewster angle. Characteristic solid-state laser device. 3. The solid-state laser device according to claim 1, wherein the solid-state laser medium is provided with a coating on a side surface thereof to reflect the excitation light. 4. The solid-state laser medium according to claim 1, wherein a side surface of the solid-state laser medium is adhered to a metal heat sink over the entire circumference. Solid state laser device. 5. The solid-state laser device according to claim 1, wherein a laser beam emitted from the solid-state laser device is reflected, scattered, or transmitted by an object to be measured. A measuring device, comprising: a light receiving unit that receives light; and performing measurement on an object to be measured based on a result of the light reception.