JPH0812498A - Substitution type garnet crystal material for solid laser - Google Patents

Abstract

PURPOSE:To produce a material for a solid laser, excitable with an AlGaAs semiconductor laser capable of oscillating at 0.8mum wavelength and having an oscillating wavelength within the range of 0.98-1.04mum without making the oscillation unstable by the disturbance from the exterior such as return light. CONSTITUTION:This substitution type garnet crystal contains at least ytterbium or lutetium and neodymium as constituent elements in the substitution type garnet crystal represented by the general formula R3A5O12 (R comprises an optional combination of one or more elements selected from yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and bismuth; A comprises an optional combinations of one or more elements selected from aluminum, scandium and gallium).

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 crystal material used as a pumping light source for an optical amplifier used in the field of optical communication.

[0002]

In the field of optical communication, as a signal for optical communication,
Light in the wavelength band of 1.3 μm and light in the wavelength band of 1.55 μm are used. The signal light is transmitted using an optical fiber, but if the signal light propagates for about 50 km or more, it is inevitable that the loss during that time cannot be ignored and the intensity gradually decreases. Therefore, it is necessary to amplify the optical signal during transmission, but it is desirable to directly amplify the optical signal in order to transmit information at an ultrahigh speed. At that time, an optical amplifier is required.

Among optical amplifiers, 1.3 μm is required in the 1.3 μm band, which is the wavelength range for subscribers.
An optical amplifier for a band, which decomposes trivalent praseodymium ion which is a rare earth element in a fluoride optical fiber and uses its stimulated emission to amplify light, is promising and is under development. There is.

FIG. 13 is an energy diagram of praseodymium. In the figure, a is excitation light, b is laser light, c is level ³ H ₄ , d is level ³ H ₅ , e is level ³ H ₆ ,
f is the level ³ F ₂ , g is the level ³ F ₃ , h is the level ³ F ₄ , and i is the level
¹ G ₄ is shown. In the 1.3 μm band optical amplifier, light is absorbed by utilizing the transition of ³ H ₄ → ¹ G ₄ having a center wavelength of about 1.02 μm, and ¹ G ₄ → ³ having a center wavelength of 1.30 μm.
It is characterized in that signal light in the 1.3 μm band is amplified by utilizing stimulated emission of H ₅ .

The 1.3 μm band optical amplifier requires an external light source of 1.02 μm wavelength for exciting praseodymium ions. As the external excitation light source, a device that has a high output, a stable oscillation wavelength, a long life, a low price and a small size is desirable. Further, in the 1.55 μm band optical amplifier, optical amplification is performed by stimulated emission of erbium ions dispersed in a quartz optical fiber, but an external excitation light source of 0.98 μm wavelength is used for optical absorption of erbium ions. ing. As an external excitation light source, it is quite the same that a high output, stable oscillation wavelength, long life, low cost and small size element are desirable.

The InGaAs semiconductor laser diode is being developed to satisfy these requirements. However, InGaAs semiconductor laser diodes
Regarding the wavelengths of 1.02 μm and 0.98 μm, there is still a problem in the stability of the oscillation wavelength, and the mass production system has not been improved yet, and the unit price is increasing. In addition, there is a problem in practical use that the operating life is short. Another problem is that an optical isolator is required to stabilize the oscillation wavelength.

The optical isolator is used to block the reflected return light of the light emitted from the semiconductor laser. This is to prevent the reflected wavelength of the reflected light from being amplified again in the resonator of the semiconductor laser so that the oscillation wavelength becomes unstable due to the influence of the light having different phases. However, as the isolator for light near 1 μm, a magnetic garnet material used for an isolator for communication wavelength (1.3 μm or 1.55 μm) causes a large loss, so a special semiconductor material such as HgCdMnTe is used. Although it is manufactured using this material, it is difficult to grow a large crystal, and if the composition deviates even a little, the characteristics are extremely changed, so that it is difficult to manufacture and the material is very expensive.

On the other hand, solid-state lasers have good wavelength stability. For example, titanium sapphire laser
It is known as a solid-state laser capable of changing the wavelength in the range of 0.7 to 1.1 μm, and is widely used at the laboratory level. At the experimental stage, titanium sapphire laser may be used to investigate the characteristics of the optical fiber for the optical amplifier, but there are the following problems in using it for a practical amplifier.

First, an argon gas laser is usually used to excite a titanium sapphire laser. Therefore, the entire laser becomes extremely large. And it can be very expensive. As a candidate that can solve these problems, a solid-state laser that can be excited by an existing inexpensive, stable, and high-power semiconductor laser is considered. At present, one of the candidates is expected to be Yb:
It is a YAG laser. Yb: Y ₃ Al ₅ O ₁₂ (Yb: YA
G) The laser is a promising laser whose room temperature continuous oscillation at 1.03 μm has been confirmed recently. To oscillate, 0.943 or 0.968 μm of external excitation light satisfying the optical absorption of ytterbium ions is required. is necessary. Such external pumping light is a choice between using the tunable solid-state laser described above or using a special semiconductor laser.
The tunable solid-state laser has the above-mentioned problems and cannot withstand the demand for small size and low cost. Further, if a semiconductor laser having a special wavelength is used for pumping, it is more advantageous to use a semiconductor laser having a desired wavelength range from the beginning, and there is no problem.
The Yb: YAG laser has an oscillation threshold of 300 mW.
It is too big to be put to practical use.

As described above, in the conventional type laser,
To be used practically as an external excitation light source for optical amplification,
There were many issues.

[0011]

As described above, the conventional solid-state laser can be excited by an existing semiconductor laser which is inexpensive and can easily obtain a high output, and has an emission wavelength of 0.98 μm.
There was no solid-state laser in the range of m to 1.04 μm, in which oscillation was not unstable due to external disturbance such as returning light.

Therefore, an object of the present invention is to produce AlGa oscillating at an existing wavelength of 0.8 μm that is inexpensive and can easily obtain high output.
Can be excited by an As semiconductor laser and has an oscillation wavelength of 0.98
It is intended to provide a material for a solid-state laser which is in the range of μm to 1.04 μm and whose oscillation does not become unstable due to external disturbance such as returning light.

[0013]

In order to solve the above-mentioned problems, the substitutional garnet crystal material for solid-state laser according to the present invention has a general formula represented by R ₃ A ₅ O ₁₂ , R is yttrium,
1 selected from lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, bismuth
A substitutional garnet crystal composed of any combination of one or more elements, wherein A is any combination of one or more elements selected from aluminum, scandium and gallium, at least neodymium and lutetium It is characterized in that it is contained as its constituent element.

The substitutional garnet crystal material for a solid-state laser according to the present invention has a general formula of R ₃ A ₅ O ₁₂ and R
Is yttrium, lantern, cerium, praseodymium,
Neodymium, samarium, europium, gadolinium,
It consists of any combination of one or more elements selected from terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and bismuth, and A is one selected from aluminum, scandium and gallium. A substitutional garnet crystal composed of any combination of the above elements is characterized by containing at least neodymium and ytterbium as its constituent elements.

That is, 0.98 μm to 1.04 μm
Substitution obtained by substituting a part of the rare earth elements constituting the garnet crystal with a combination of neodymium and lutetium or a combination of neodymium and ytterbium as a material for a solid-state laser for a practical pumping light source in the wavelength range to A type garnet crystal material is provided.

More specifically, as the first substitution type garnet crystal material, the general formula is represented by R ₃ A ₅ O ₁₂ , and R is yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, eurobium, It consists of any combination of one or more elements selected from gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and bismuth, where A is aluminum, scandium,
A substitutional garnet crystal, which is composed of an arbitrary combination of one or more elements selected from gallium and which contains at least neodymium and lutetium as its constituent elements, has an oscillation wavelength in the wavelength region of 0.98 μm to 1.04 μm. Is a substitutional garnet crystal material for a solid-state laser,

As the second substitution type garnet crystal material, the general formula is represented by R ₃ A ₅ O ₁₂ , R is yttrium,
1 selected from lanthanum, cerium, praseodymium, neodymium, samarium, eurobium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, bismuth
It is composed of any combination of one or more elements, and A is composed of any combination of one or more elements selected from aluminum, scandium and gallium.
0.98 μm in a substitutional garnet crystal containing at least neodymium and ytterbium as its constituent elements
Is a substitutional garnet crystal material for a solid-state laser, which has an oscillation wavelength in a wavelength range from 1 to 1.04 μm,

The third substitutional garnet crystal material is a substitutional garnet crystal material for a solid-state laser, characterized in that either or both of calcium and magnesium are added to the first substitutional garnet crystal material. .

In the first and third substitutional garnet crystal materials, the occupancy rate of neodymium is 1 of the whole rare earth elements.
% Or more, and the occupancy rate of lutetium is preferably 30% or less of the whole rare earth element. In the third substitutional garnet crystal material, the occupancy rate of neodymium is 1% or more of the whole rare earth element, and lutetium is The occupancy rate is 30% or less of the whole rare earth element, and the addition amount of each of the added calcium or magnesium alone, and the total addition amount of the added calcium and magnesium are preferably the same as that of lutetium.

Further, in the second substitution type garnet crystal material, the occupancy rate of neodymium is 1% of the whole rare earth elements.
As described above, the occupancy rate of ytterbium is preferably 40% or less of the whole rare earth element.

Further, the rare earth constituent elements other than neodymium, ytterbium and lutetium are desirably those in which one or more elements selected from lanthanum, gadolinium and yttrium are arbitrarily combined.

[0022]

The garnet crystal is represented by the general formula R ₃ A ₅ O ₁₂ , and it is possible to substitute the R portion with a rare earth element and the A portion with aluminum, scandium or gallium. In the present invention, in the composition of various substitution type garnet crystals that have been subjected to such substitution, a part of R is further substituted with another rare earth element such as neodymium, and a part of A is substituted with aluminum, scandium and gallium, respectively. It is possible to In the present invention, among the compositions of various substitution type garnet crystals having such substitution, R
A substitution type garnet crystal material containing either a combination of neodymium and lutetium or a combination of neodymium and ytterbium as an essential condition is used in the part.

The energy level of the substituting element causes splitting when a field created by a neighboring atom or atomic group is sensed. The field is called a ligand field, which is determined by changing the host crystal system. The quantum field changes, and the energy level of the substituting element shifts by an amount corresponding to the property of the energy level. Therefore, the oscillation wavelength can be shifted within a certain range by appropriately selecting the crystal system of the host. For example, in a garnet crystal, the ligand field greatly changes depending on whether A is mostly aluminum or gallium. Therefore, for light in the vicinity of 1 μm, 0.98 μm to 1.04 μ is sufficient.
It is possible to select the oscillation wavelength within the range of m.

Furthermore, the absorption wavelengths can be set to some extent by absorption based on a plurality of substituting elements, and further the absorbed energy can cause internal conversion between the same atoms,
By utilizing quantum mechanical interaction such as intersystem crossing that occurs between different atoms, it can be successfully distributed to the oscillating upper level of the light emitting atom, and inversion distribution between the oscillating levels can be created.

Since the substitutional garnet crystal material for solid-state laser according to the present invention contains neodymium as a rare earth element, the absorption transition from the ground level to ⁴ F _5/2 results in an inexpensive 0.81 μm wavelength AlGaAs. It can be excited by a semiconductor laser, and from the non-emission transition to the ⁴ F _3/2 level, the non-emissive neodymium ion is automatically emitted to the trivalent ytterbium ion or the tetravalent lutetium ion by the interaction between dipoles. Energy transfer, and it is possible to form a population inversion for stimulated emission of ytterbium or lutetium ions in the ² F _5/2 level around 1 μm.

By appropriately selecting the constituent ratio of gallium, aluminum and scandium which are the constituent elements of A, it is possible to selectively oscillate at a desired wavelength within the range of 0.98 μm to 1.04 μm. In conventional garnet crystals for solid-state lasers that use neodymium as the active ion, the content of neodymium should be set to the whole rare earth in order to avoid concentration quenching caused by increasing the content of neodymium ion in consideration of absorption / emission efficiency. It was selected around 1%. However, the role of neodymium ions in the present invention is not to emit light in a deviated state, but to efficiently absorb 0.81 μm excitation light and transfer energy to nearby ytterbium ions or lutetium ions. That is, the content is preferably such that light emission by itself does not easily occur, and is selected as 1% or more of the whole rare earth element.

When a combination of neodymium and lutetium is contained, the addition of either calcium or magnesium improves the luminous efficiency. The reason is as follows.

Calcium and magnesium normally substitute at a position occupied by an ion having a trivalent valence while taking a divalent valence, and as a result, electrically neutrality cannot be maintained. In other words, most of lutetium changes its valence from normal trivalent to tetravalent in order to maintain electrical neutrality. Such a valence control method is generally called electric value compensation. By increasing the number of lutetium ions having a tetravalent valence, the efficiency of the solid-state laser is dramatically improved. Incidentally, the lutetium ion, which usually has a valence of 3, does not participate in the light emission in the infrared region at all.

The occupancy of each substituting element is as follows: neodymium is 1% or more of the total rare earth elements, lutetium is at most 30% or less, and ytterbium is at most 4%.
About 0% or less is desirable. Neodymium, ytterbium,
When lanthanum, gadolinium, or yttrium is selected as the constituent element of R other than lutetium, the threshold value becomes particularly low when a laser is manufactured. This is because lanthanum, gadolinium and yttrium have no absorption in the wavelength range of 0.98 to 1.04 μm.

The present invention is based on the above-mentioned features.
It is possible to provide a substitutional garnet crystal material for a solid-state laser, which has an oscillation wavelength in the wavelength range of m to 1.04 μm.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0032]

Example 1 Examples 1-1 to 1-1 shown below
In No. 5, a bulk single crystal of the substitutional garnet crystal material for a solid-state laser of the present invention was produced by the Czochralski method. Further, the bulk single crystal is
In order to evaluate the characteristics as a laser material, one surface is processed into a flat surface, one surface is a spherical surface with a radius of 5 cm, and a disk with a thickness of 1.5 mm. About 99% is applied to the flat surface at a wavelength of 0.98 to 1.04 μm. The spherical surface was coated with a reflectance of about 97%. FIG. 1 shows Examples 1-1 to 1-21 according to the present invention.
A measurement system for evaluating the characteristics of the substitutional garnet crystal material for solid-state laser as a laser material is shown. An AlGaAs semiconductor laser having a wavelength of 0.808 μm was used as the excitation light source. The excitation light 3 emitted from the semiconductor laser 1 is coupled to the lens 2,
While converging through 2 ′ and 2 ″, the light enters the disk 4 of the substitutional garnet crystal material for solid-state lasers of Examples 1-1 to 1-21 and emits light 5 from the disk 4 with an optical spectrum analyzer 6. The laser oscillation characteristics were evaluated by observing.

[0033]

Example 1-1] This example embodiment the composition formula as shown in _{1 R 3-XY Nd X Lu} Y A 5-Z Ga Z O 1 2 and R _3-XY
Nd _X Lu _Y A1 _5-ZW A2 _W Ga _Z O ₁₂ (X = 0.13
Y = 0.80, Z = 0.17, W = 2.00, A and A1 are Al, A2 is Sc, R is La, Ce, Pr, B
i, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er,
A garnet crystal material for a laser of the present invention represented by any one of Tm and Yb) was produced, and the laser oscillation characteristics were investigated using the measurement system shown in FIG. Table 1
A threshold value represented by the laser oscillation wavelength of the substitutional garnet crystal material for solid-state laser of the present embodiment in which R, A, A1 and A2 are appropriately selected and the light intensity of the excitation light source which is the minimum required for laser oscillation. The elements shown below are shown. Any of the substitutional garnet crystal materials for solid-state lasers of this example are 0.9.
Laser oscillation was performed at a wavelength in the range of 8 to 1.04 μm. In addition, any of the materials of this example oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional materials. Particularly, when R is set to La, Gd, and Y, the threshold value is low. This is because La, Gd, and Y do not have absorption near the oscillation wavelength.

[0034]

Example 1-2 This example is the same as Example 1 except that the composition formulas R _3-XY Nd _X Lu _Y A ₅ O ₁₂ and R _3-XY Nd _X Lu are used.
_Y A1 _5-W A2 _W O ₁₂ (X = 0.13, Y = 0.80, W
= 2.00, A and A1 are Ga, A2 is Sc, and R is L
a, Ce, Pr, Bi, Sm, Eu, Gd, Tb, D
y, Ho, Y, Er, Tm, or Yb), a substitutional garnet crystal material for a solid-state laser of the present invention is prepared, and laser oscillation characteristics are measured using the measurement system shown in FIG. It is a survey. Table 2 shows elements for which the lasing wavelength and threshold value of the substitutional garnet crystal material for solid-state laser of the present embodiment, in which R, A, A1 and A2 are appropriately selected, are selected. In the same manner as in Example 1, any of the substitutional garnet crystal materials for solid-state lasers of this Example had a value of 0.
Laser oscillation was performed at a wavelength in the range of 98 to 1.04 μm. In addition, any of the materials of this example oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional materials.

[0035]

[Embodiment 1-3] This embodiment is similar to Embodiment 1,
Compositional formula: Y _3-XY Nd _X Lu _Y Al _5-Z Ga _Z O ₁₂ (X = 0.
13, Y = 0.80), a substitutional garnet crystal material for a solid-state laser of the present invention was produced, and the relationship between laser oscillation characteristics and Ga concentration Z was investigated by using the measurement system shown in FIG. is there. FIG. 2 shows the relationship between the Ga concentration Z and the laser oscillation wavelength and oscillation threshold of the substitutional garnet crystal material for solid-state laser of this example. The lasing wavelength tends to become shorter as the Ga concentration Z increases, but any of the substitutional garnet crystal materials for solid-state lasers of this example have a wavelength of 0.
Laser oscillation was performed at a wavelength in the range of 98 to 1.04 μm. In addition, although the materials of all of the examples have variations depending on the Ga concentration Z, it is difficult to realize with the conventional materials.
It oscillated at a low threshold value of mW or less.

[0036]

[Embodiment 1-4] This embodiment is similar to Embodiment 1,
Composition formula Gd _3-XY Nd _X Lu _Y Al _5-ZW Ga _Z Sc _W O
₁₂ (X = 0.13, Y = 0.80, W = 2.00) The substitutional garnet crystal material for solid-state laser of the present invention represented by the formula ₁₂ was prepared, and laser oscillation was performed using the measurement system shown in FIG. The relationship between the characteristics and the Ga concentration Z is investigated. FIG. 3 shows the relationship between the laser oscillation wavelength, the threshold, and the Ga concentration Z of the substitutional garnet crystal material for solid-state laser of this example. The laser oscillation wavelength tends to become shorter as the Ga concentration Z increases, but any of the laser garnet crystal materials of this example lased at a wavelength in the range of 0.98 to 1.04 μm. In addition, although the materials of all of the present examples varied depending on the Ga concentration Z, they oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional materials.

[0037]

[Embodiment 1-5] This embodiment is similar to Embodiment 1,
Composition formula Y_3-XYVLa_VNd_XLu_YAl_{Five- Z}Ga_ZO₁₂(X
= 0.13, Y = 0.80, Z = 0.17)
Fabrication of substitutional garnet crystal material for solid-state laser of the present invention
Then, using the measurement system shown in FIG.
The relationship between the concentrations v is investigated. FIG. 4 shows the present embodiment.
Laser oscillation wave of substitutional garnet crystal material for solid-state laser
The relationship between the length, the threshold value, and the La concentration v is shown. Laser oscillation wave
The length tends to become shorter as the La concentration v increases.
However, any of the laser garnet crystal materials of this embodiment
Laser oscillation in the wavelength range of 0.98 to 1.04 μm
Was. In addition, any of the materials of the present examples are
Despite variations, it was difficult to achieve with conventional materials
It oscillated at a low threshold value of 100 mW or less.

In the present embodiment 1-5, R _3-XY Nd _X L
In u _Y A _5-Z Ga _Z O ₁₂ , R is Y and La, A is Al,
The garnet crystal material for laser of the present invention having X = 0.13, Y = 0.80, Z = 0.17 has been described, but R is L
a, Ce, Pr, Bi, Sm, Eu, Gd, Tb, D
Any one or more elements of y, Ho, Y, Er, Tm, and Yb, A is one or more elements of Al and Sc, and X, Y, and Z are 0 <X <3. 0 <Y <3,0
Even in the range of ≦ Z ≦ 5, laser oscillation is performed at a wavelength in the range of 0.98 to 1.04 μm at a low threshold value of 100 mW or less by excitation of a 0.8 μm band semiconductor laser as in the case of the material of this example. Needless to say.

[0039]

Example 1-6 In this example, as shown in Example 1, the composition formula R _3-abc Nd _a Lu _b Ca _c A _{5-d- e} Ga _d Mg _e O was used.
₁₂ and R _3-abc Nd _a Lu _b Ca _c A1 _5-def A2 _f G
a _d Mg _e O ₁₂ (a = 0.1, b = 0.15, c = 0.0
75, d = 1, e = 0.075, f = 2.0, A and A1 are Al, A2 is Sc, R is La, Ce, Pr, B
i, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er,
A substitutional garnet crystal material for a solid-state laser of the present invention represented by one or more elements selected from Tm and Yb) was produced, and the laser oscillation characteristics were investigated using the measurement system shown in FIG. is there. Table 3 shows a threshold value represented by the laser oscillation wavelength of the substitutional garnet crystal material for a solid-state laser of the present embodiment in which R, A, A1 and A2 are appropriately selected and the light intensity of the excitation light source minimum required for laser oscillation. Indicates the selected element. Any of the substitutional garnet crystal materials for solid-state lasers of this example lased at a wavelength in the range of 0.98 to 1.04 μm. In addition, any of the materials of this example oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional materials.

[0040]

[Embodiment 1-7] This embodiment is similar to Embodiment 1,
Compositional formulas R _3-abc Nd _a Lu _b Ca _c A _5-d Mg _d O ₁₂ and R _3-abc Nd _a Lu _b Ca _{c A} 1 _{5-ed A} 2 _e Mg _d O
₁₂ (a = 0.13, b = 0.9, c = 0.4, d = 0.
5, e = 2.0, A and A1 are Ga, A2 is Sc, R
Is La, Ce, Pr, Bi, Sm, Eu, Gd, Tb,
Dy, Ho, Y, Er, Tm, and Yb), a substitution type garnet crystal material for a solid-state laser of the present invention represented by one or more elements) is produced, and the measurement system shown in FIG. 1 is used. This is an investigation of laser oscillation characteristics. R in Table 4
Elements for which the laser oscillation wavelength and the threshold value of the substitutional garnet crystal material for solid-state laser of the present embodiment, in which A, A1 and A2 are appropriately selected, will be shown. In the same manner as in Example 1-6, any of the substitutional garnet crystal materials for solid-state lasers of this example lased at a wavelength in the range of 0.98 to 1.04 μm. In addition, any of the materials of this example oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional materials.

[0041]

[Embodiment 1-8] This embodiment is similar to Embodiment 1,
Compositional formula Y _3-abc Nd _a Lu _b Ca _c Al _{5- de} Ga _d Mg _e
O ₁₂ (a = 0.15, b = 0.5, c = 0.2, e =
0.3), a substitutional garnet crystal material for a solid-state laser of the present invention was produced, and the relationship between the laser oscillation characteristic and the Ga concentration d was investigated using the measurement system shown in FIG.
FIG. 5 shows the relationship between the Ga concentration d and the laser oscillation wavelength and oscillation threshold of the substitutional garnet crystal material for solid-state laser of this example. The lasing wavelength tends to become shorter as the Ga concentration d increases, but in any of the substitutional garnet crystal materials for solid-state lasers of this example, the lasing wavelength is 0.98 to 1.0.
Laser oscillation was performed at a wavelength in the range of 4 μm. In addition, all the materials of the present examples oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional material, although there was variation depending on the Ga concentration d.

[0042]

[Embodiment 1-9] This embodiment is similar to Embodiment 1,
Composition formula _{Gd 3-abc Nd a Lu b} Ca c Al 5-def Ga d S
c _e Mg _f O ₁₂ (a = 0.13, b = 0.80, c = 0.
4, e = 2, f = 0.4), a substitutional garnet crystal material for a solid-state laser of the present invention is produced, and the relationship between the laser oscillation characteristic and the Ga concentration d is measured by using the measurement system shown in FIG. It is a survey. FIG. 6 shows the laser oscillation wavelength, threshold value, and Ga of the substitutional garnet crystal material for solid-state laser of this example.
The relationship of the concentration d is shown. The laser oscillation wavelength tends to become shorter as the Ga concentration d increases, but the laser garnet crystal material of any of the present examples has a wavelength of 0.98 to 1.04.
Laser oscillation was performed at a wavelength in the range of μm. In addition, all the materials of the present examples oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional material, although there was variation depending on the Ga concentration d.

[0043]

Example 1-10 This example is similar to Example 1 and has the composition formula Y _3-abcv La _v Nd _a Lu _b Ca _c Al _5-de.
Ga _d Mg _e O ₁₂ (a = 0.13, b = 0.80, c =
0.2, d = 1.0, e = 0.6), a substitutional garnet crystal material for a solid-state laser of the present invention was produced, and laser oscillation characteristics and La concentration were measured using the measurement system shown in FIG. This is a survey of the relationship of V. FIG. 7 shows the relationship between the laser oscillation wavelength, the threshold, and the La concentration V of the substitutional garnet crystal material for solid-state laser of this example. The laser oscillation wavelength is La
Although the concentration V tends to become shorter as the concentration V increases, any of the substitutional garnet crystal materials for solid-state lasers of this example lased at a wavelength in the range of 0.98 to 1.04 μm. Further, all the materials of the present examples oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional materials, although there were variations depending on the La concentration V.

In this Example 1-10, R _3-abc N
_{d a Lu b Ca c A 5} -de Ga d Mg e in O _{1 2} R is Y and La, but A was described the present invention for laser garnet crystal material Al, R is La, Ce, Pr, Bi, S
m, Eu, Gd, Tb, Dy, Ho, Y, Er, Tm,
Any one or more elements of Yb, A is Al, S
Any one or more elements of c, and a, b and d are 0
<A <3,0 <b <3, 0 ≦ d ≦ 5,
As in the case of the material of this example, 0.98 to 0.98 at a low threshold value of 100 mW or less by excitation of a 0.8 μm semiconductor laser.
It goes without saying that laser oscillation occurs at a wavelength in the range of 1.04 μm.

[0045]

EXAMPLES 1-11 This example, composition formula R _3-XY Nd as indicated in Example _{1 X Yb Y A 5-Z} Ga Z O 1 2 and R
_3-XY Nd _X Yb _Y A1 _5-ZW A2 _W Ga _Z O ₁₂ (X = 0.1
3, Y = 0.80, Z = 0.17, W = 2.0, A and A1 are Al, A2 is Sc, R is La, Ce, Pr, B
i, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er,
A garnet crystal material for a laser of the present invention represented by any one of Tm and Lu) was produced, and the laser oscillation characteristics were investigated using the measurement system shown in FIG. Table 5
A threshold value represented by the laser oscillation wavelength of the substitutional garnet crystal material for solid-state laser of the present embodiment in which R, A, A1 and A2 are appropriately selected and the light intensity of the excitation light source which is the minimum required for laser oscillation. The elements shown below are shown. Any of the substitutional garnet crystal materials for solid-state lasers of this example are 0.9.
Laser oscillation was performed at a wavelength in the range of 8 to 1.04 μm. In addition, any of the materials of this example oscillated at a threshold value of 100 mW or less, which was difficult to realize with the conventional materials.

[0046]

EXAMPLES 1-12 This example, in the same manner as in Example 1, the composition formula _{R 3-XY Nd X Yb Y} A 5 O 12 and R _3-XY N
d _X Yb _Y A1 _5-W A2 _W O ₁₂ (X = 0.15, Y = 0.8
0, W = 2.0, A and A1 are Ga, A2 is Sc, R
Is La, Ce, Pr, Bi, Sm, Eu, Gd, Tb,
Dy, Ho, Y, Er, Tm, or any one element of Lu)), a substitutional garnet crystal material for a solid-state laser of the present invention is produced, and laser oscillation characteristics are measured using the measurement system shown in FIG. It is a survey. Table 6 shows the elements for which the laser oscillation wavelength and the threshold value of the substitutional garnet crystal material for solid-state laser of the present example in which R, A, A1 and A2 are selected appropriately are selected. In the same manner as in Example 1-11, any of the substitutional garnet crystal materials for solid-state lasers of this example lased at a wavelength in the range of 0.98 to 1.04 μm. In addition, any of the materials of this example oscillated at a threshold value of 100 mW or less, which was difficult to realize with the conventional materials.

[0047]

EXAMPLES 1-13 This example, in the same manner as in Example 1, the composition formula _{Y 3-XY Nd X Yb Y} Al 5-Z Ga Z O 12 (X =
0.1, Y = 1.0), the substitutional garnet crystal material for a solid-state laser of the present invention was produced, and the relationship between the laser oscillation characteristic and the Ga concentration Z was investigated using the measurement system shown in FIG. It is a thing. FIG. 8 shows the relationship between the Ga concentration Z and the laser oscillation wavelength and oscillation threshold of the substitutional garnet crystal material for solid-state laser of this example. The lasing wavelength tends to become shorter as the Ga concentration Z increases, but any of the substitutional garnet crystal materials for solid-state lasers of this example have a wavelength of 0.
Laser oscillation was performed at a wavelength in the range of 98 to 1.04 μm. In addition, although the materials of all of the examples have variations depending on the Ga concentration Z, it is difficult to realize with the conventional materials.
It oscillated at a threshold value of mW or less.

[0048]

EXAMPLES 1-14 This example, in the same manner as in Example 1, the composition formula _{Gd 3-XY Nd X Yb Y} Al 5-ZW Ga Z Sc W O
₁₂ (X = 0.13, Y = 1.2, W = 2.00) The substitutional garnet crystal material for a solid-state laser of the present invention represented by the formula ₁₂ was produced, and laser oscillation was performed using the measurement system shown in FIG. Characteristics and G
The relationship of the a concentration Z is investigated. FIG. 9 shows the relationship between the laser oscillation wavelength, the threshold value, and the Ga concentration Z of the substitutional garnet crystal material for solid-state laser of this example. The laser oscillation wavelength tends to become shorter as the Ga concentration Z increases, but any of the laser garnet crystal materials of this example lased at a wavelength in the range of 0.98 to 1.04 μm. In addition, although the materials of all of the present examples varied depending on the Ga concentration Z, they oscillated at a threshold value of 100 mW or less, which was difficult to realize with the conventional materials.

[0049]

EXAMPLES 1-15 This example, in the same manner as in Example 1, the composition formula _{Y 3-XYV La V Nd X} Yb Y Al 5- Z Ga Z O 12
A substitutional garnet crystal material for a solid-state laser of the present invention represented by (X = 0.13, Y = 1.00, Z = 0.17) was produced, and laser oscillation characteristics were measured using the measurement system shown in FIG. And L
The relationship between the a and the concentration V is investigated. FIG. 10 shows the relationship between the laser oscillation wavelength, the threshold value, and the La concentration V of the substitutional garnet crystal material for solid-state laser of this example. The lasing wavelength tends to become shorter as the La concentration V increases, but any of the substitutional garnet crystal materials for solid-state lasers of this example lased at a wavelength in the range of 0.98 to 1.04 μm. In addition, the material of any of the examples is La
Although there was variation depending on the concentration V, oscillation occurred at a low threshold value of 100 mW or less, which was difficult to realize with conventional materials.

In Example 1-15, R _3-XY Nd _{X was used.}
In Yb _Y A _5-Z Ga _Z O ₁₂ , R is Y and La and A is Al.
The garnet crystal material for a laser according to the present invention has been described. R is La, Ce, Pr, Bi, Sm, Eu, Gd,
Tb, Dy, Ho, Y, Er, Tm, Lu is one or more kinds of elements, A is Al, Sc, and one or more kinds of elements, and X, Y and Z are 0 <X. <3,0 <
Even in the range of Y <3, 0 ≦ Z ≦ 5, as in the case of the material of the present embodiment, 100 is obtained by pumping a 0.8 μm semiconductor laser.
It goes without saying that laser oscillation occurs at a wavelength in the range of 0.98 to 1.04 μm at a low threshold value of mW or less.

[0051]

EXAMPLES 1-16 This example, in the same manner as in Example 1, the composition formula _{R 3-XY Nd X Lu Y} A 5 O 12 and R _3-XY N
d _X Lu _Y A1 _5-W A2 _W O ₁₂ (X = 0.20, Y = 0.2
0, W = 2.0, A and A1 are Al, A2 is Sc, R
Is La, Ce, Pr, Bi, Sm, Eu, Gd, Tb,
Dy, Ho, Y, Er, Tm, or Yb), a substitutional garnet crystal material for a solid-state laser of the present invention is produced, and laser oscillation characteristics are measured using the measurement system shown in FIG. It is a survey. Table 7 shows elements for which the laser oscillation wavelength and the threshold value of the substitutional garnet crystal material for the solid-state laser of the present example in which R, A, A1 and A2 are selected appropriately are selected. Any of the substitutional garnet crystal materials for solid-state lasers of this example lased at a wavelength in the range of 0.98 to 1.04 μm. In addition, any of the materials of this example oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional materials.

[0052]

Example 1-17 This example is the same as Example 1 _except that the composition formulas R _3-abc Nd _a Lu _b Ca _c A _5-d Mg _d O ₁₂ and R _3-abc Nd _a Lu _b Ca are used. _c A1 _5-ed A2 _e Mg _d O
₁₂ (a = 0.20, b = 0.20, c = 0.10, d =
0.10, e = 2.0, A and A1 are Al, A2 is S
c and R are La, Ce, Pr, Bi, Sm, Eu, Gd,
A substitution type garnet crystal material for a solid-state laser of the present invention represented by one or more kinds of elements selected from Tb, Dy, Ho, Y, Er, Tm, and Yb) was prepared, and the measurement system shown in FIG. This is an investigation of laser oscillation characteristics using. Table 8
The elements for which the lasing wavelength and the threshold value of the substitutional garnet crystal material for solid-state laser of this embodiment, in which R, A, A1 and A2 are appropriately selected, are selected are shown in FIG. Any of the substitutional garnet crystal materials for solid-state lasers of this example are 0.9.
Laser oscillation was performed at a wavelength in the range of 8 to 1.04 μm. In addition, any of the materials of this example oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional materials.

[0053]

EXAMPLES 1-18 This example, in the same manner as in Example 1, the composition formula _{R 3-XY Nd X Yb Y} A 5 O 12 and R _3-XY N
d _X Yb _Y A1 _5-W A2 _W O ₁₂ (X = 0.20, Y = 0.2
0, W = 2.0, A and A1 are Al, A2 is Sc, R
Is La, Ce, Pr, Bi, Sm, Eu, Gd, Tb,
Dy, Ho, Y, Er, Tm, or any one element of Lu)), a substitutional garnet crystal material for a solid-state laser of the present invention is produced, and laser oscillation characteristics are measured using the measurement system shown in FIG. It is a survey. Table 9 shows elements for which the lasing wavelength and threshold value of the substitutional garnet crystal material for a solid-state laser of the present embodiment, in which R, A, A1 and A2 are appropriately selected, are selected. Any of the substitutional garnet crystal materials for solid-state lasers of this example lased at a wavelength in the range of 0.98 to 1.04 μm. In addition, any of the materials of this example oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional materials.

[0054]

EXAMPLES 1-19 This example, in the same manner as in Example 1, the composition formula _{R 3-XY Nd X Yb Y} A 5 O 12 and R _3-XY N
d _X Yb _Y A1 _5-W A2 _W O ₁₂ (X = 0.20, Y = 0.2
0, W = 2.0, A and A1 are Al, A2 is Sc, R
Is La, Ce, Pr, Bi, Sm, Eu, Gd, Tb,
Dy, Ho, Y, Er, Tm, or any one element of Lu)), a substitutional garnet crystal material for a solid-state laser of the present invention is produced, and laser oscillation characteristics are measured using the measurement system shown in FIG. It is a survey. Table 10 shows the elements for which the lasing wavelength and threshold value of the substitutional garnet crystal material for solid-state laser of the present embodiment, in which R, A, A1 and A2 are appropriately selected, are selected. Any of the substitutional garnet crystal materials for solid-state lasers of this example are 0.98 to 1.04 μm.
Laser oscillation was performed at a wavelength in the range. In addition, it is difficult to realize the material of any of the present embodiments with the conventional material, which is 100 mW.
It oscillated at the following low thresholds.

[0055]

EXAMPLES 1-20 This example, in the same manner as in Example 1, the composition formula _{Y 3-XY Nd X Yb Y} Al 5-Z Ga Z O 12 (X =
0.20, Y = 0.18), a substitutional garnet crystal material for a solid-state laser of the present invention was produced, and the relationship between laser oscillation characteristics and Ga concentration Z was investigated using the measurement system shown in FIG. It is a thing. FIG. 14 shows the relationship between the Ga concentration Z and the laser oscillation wavelength and oscillation threshold of the substitutional garnet crystal material for solid-state laser of this example. The laser oscillation wavelength is G
Although the a concentration Z tends to become shorter as the concentration a increases, any of the substitutional garnet crystal materials for solid-state lasers of this example lased at a wavelength in the range of 0.98 to 1.04 μm. In addition, although the materials of all of the present examples varied depending on the Ga concentration Z, they oscillated at a low threshold value of 100 mW or less, which was difficult to realize with the conventional materials.

[0056]

[Embodiment 1-21] This embodiment is similar to Embodiment 1.
The composition formula Gd_3-XYNd_XYb_YAl_5-ZGa _ZO₁₂(X
= 0.19, Y = 0.18)
A substitutional garnet crystal material for the z was prepared and shown in FIG.
Use the measurement system to adjust the relationship between the laser oscillation characteristics and Ga concentration Z.
It has been examined. FIG. 15 shows the solid-state laser device of this embodiment.
Laser oscillation wavelength and oscillation of the modified garnet crystal material
The relationship between the threshold value and the Ga concentration Z is shown. The laser oscillation wavelength is
It tends to become shorter as the Ga concentration Z increases, but
Displacement type garnet crystal material for solid-state laser of this embodiment
Laser oscillation at wavelengths in the range of 0.98 to 1.04 μm
did. In addition, any of the materials of the present examples are different in the Ga concentration Z.
However, it is difficult to realize with conventional materials
It also oscillated at a low threshold value of 100 mW or less.

[0057]

[Embodiment 2] Embodiments 2-1 to 2-3 shown below
Then, an optical waveguide having a core portion made of the substitutional garnet crystal material for solid-state laser according to the present invention as shown in FIG. 11 was produced. The optical waveguide shown in FIG. 11 is Y ₃ Al ₅ O
PbO and B ₂ O ₃ are deposited on the substrate 9 made of ₁₂ (YAG).
By the liquid phase epitaxial growth method (LPE method) using a flux as a flux, the solid-state laser of the present invention having a composition slightly larger than that of YAG and having a small lattice constant difference from the YAG substrate to such an extent that the crystallinity does not decrease. Growing a layer of substitutional garnet crystal material, processing the layer made of this garnet crystal material into a core 10 by photolinography and ion milling, and finally growing an upper clad 11 made of YAG by the LPE method. Was easily formed. The substrate material itself acts as the lower clad. Furthermore, in order to evaluate the characteristics when the substitutional garnet crystal material for solid-state laser of Example 2-1 to Example 2-3 is used as a waveguide type laser material, both ends of the optical waveguide are cut and polished. , About 99 at the wavelength of 0.98 to 1.04 μm at the light emitting / receiving end 12 of both end faces.
% Reflectance coating was applied.

FIG. 12 shows a measurement system for evaluating the characteristics of the substitutional garnet crystal materials for solid-state lasers of Examples 2-1 to 2-3 as a laser material. An AlGaAs semiconductor laser 1 having a wavelength of 0.810 μm was used as the excitation light source. Excitation light 3 emitted from the semiconductor laser 1 is incident on an optical fiber 7 using a lens, and passes through the optical fiber 7 to an optical waveguide 8 having a core made of the substitutional garnet crystal material for solid-state lasers of Examples 15 and 16. An optical fiber 7 ′ receives the light 5 which is incident and emitted from the emission end of the optical waveguide 8.
Then, the laser oscillation characteristics were evaluated by observing with the optical spectrum analyzer 6.

[0059]

[Example 2-1] In this example, the composition formula Y _3-XY Nd _X Lu was used.
An optical waveguide having a core of the substitutional garnet crystal material for a solid-state laser of the present invention represented by _Y Al _5-Z Ga _Z O ₁₂ was prepared, and laser oscillation characteristics were investigated using the measurement system shown in FIG. Is. In this embodiment, the refractive index of the substitutional garnet crystal material for solid-state laser is set to Y as the material of the substrate.
X = 0.13, Y = 0.80, Z = 0.17 were selected so as to be slightly larger than AG and to have a lattice constant difference with YAG of 0.00085 nm, which is a range in which crystallinity does not decrease. . The optical waveguide having the core of the substitutional garnet crystal material for solid-state laser of this example lased at a wavelength of 1.025 μm. Also, it oscillates at a threshold of 10 mW,
It oscillated at a low threshold value of 100 mW or less, which was difficult to realize with conventional materials.

[0060]

Example 2-2 In this example, the composition formula Y _3-abc Nd _a L is used.
An optical waveguide having a core of the substitutional garnet crystal material for a solid-state laser of the present invention represented by u _b Ca _c A1 _5-de Ga _d Mg _e O ₁₂ was produced, and laser oscillation was performed using the measurement system shown in FIG. This is a survey of characteristics. In this embodiment, the refractive index of the substitutional garnet crystal material for solid-state laser is set to be slightly larger than that of the material of the substrate, YAG, and the difference in lattice constant from YAG is 0.000 within the range where crystallinity does not decrease.
A = 0.13, b = 0.80, c so that it becomes 85 nm.
= 0.40, d = 0.17, e = 0.40.
The optical waveguide having the core of the substitutional garnet crystal material for solid-state laser of this example lased at a wavelength of 1.025 μm. Further, it oscillated at a threshold value of 8 mW and oscillated at a low threshold value of 100 mW or less, which was difficult to realize with conventional materials.

[0061]

Example 2-3 In this example, the composition formula Y _3-XY Nd _X Yb is used.
An optical waveguide having a core of the substitutional garnet crystal material for a solid-state laser of the present invention represented by _Y Al _5-Z Ga _Z O ₁₂ was prepared, and laser oscillation characteristics were investigated using the measurement system shown in FIG. Is. In this embodiment, the refractive index of the substitutional garnet crystal material for solid-state laser is set to Y as the material of the substrate.
X = 0.13, Y = 0.80, Z = 0.17 were selected so as to be slightly larger than AG and to have a lattice constant difference with YAG of 0.00085 nm, which is a range in which crystallinity does not decrease. . The optical waveguide having the core of the substitutional garnet crystal material for solid-state laser of this example lased at a wavelength of 1.025 μm. Also, it oscillates at a threshold of 13 mW,
It oscillated at a low threshold value of 100 mW or less, which was difficult to realize with conventional materials.

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

As described above, the substitutional garnet crystal material for solid-state laser of the present invention is 0.98 to 1.04 μm.
Since it oscillates at a low threshold value of 100 mW or less in the m wavelength band, it has an advantage that it can be put to practical use. Further, unlike the conventional materials, a semiconductor laser that oscillates in the 0.8 μm band that is inexpensive and has a high output can be used as the excitation light source, so that it has great economic and performance advantages.

In a specific embodiment of the present invention,
Due to experimental and time constraints, great restrictions were made on the composition of the material. However, as long as there is no significant change from these compositions and no problem occurs in crystal growth, the effect of the present invention Of course, for the materials that give rise to, they are within the scope of the invention.

In addition, when crystal growth is performed, it is inevitable that some unintended elements such as platinum, which is a crucible material, are not positively mixed, so that these mixed elements do not essentially affect the effect of the present invention. As far as possible, materials containing these mixed elements are also included in the scope of the present invention.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a measurement system for evaluating characteristics of a substitutional garnet crystal material for a solid-state laser of Example 1 (Examples 1-1 to 1-15) as a laser material.

[2] the composition formula _{Y 3-XY Nd X Lu Y} Al 5-Z Ga Z O
_The figure which shows the oscillation wavelength of the substitution type garnet crystal material for solid-state lasers of the Example represented by ₁₂ (X = 0.13, Y = 0.80), the threshold value, and the Ga concentration Z.

FIG. 3 Compositional formula Gd _3-XY Nd _X Lu _Y Al _5-ZW Ga _Z S
c _W O ₁₂ (X = 0.13, Y = 0.80, W = 2.0
The figure which shows the laser oscillation wavelength of the substitutional garnet crystal material for solid-state lasers of the Example represented by 0), the threshold value, and Ga concentration Z.

[Fig. 4] Composition formula Y _3-XYV La _V Nd _X Lu _Y Al _5-Z Ga _Z
The laser oscillation wavelength, threshold value, and La concentration V of the substitutional garnet crystal material for solid-state laser of Example 1-5 represented by O ₁₂ (X = 0.13, Y = 0.80, Z = 0.17) FIG.

FIG. 5: Compositional formula Y _3-abc Nd _a Lu _b Ca _c Al _5-de G
a _d Mg _e O ₁₂ (a = 0.15, b = 0.5, c = 0.
2, e = 0.3), the lasing wavelength, threshold value, and G of the substitutional garnet crystal material for solid-state laser of the embodiment
The figure which shows the relationship of a density d.

FIG. 6 is a composition formula Gd _3-abc Nd _a Lu _b Ca _c Al.
_5-def Ga _d Sc _e Mg _f O ₁₂ (a = 0.13, b = 0.
80, c = 0.4, e = 2, f = 0.4) showing the relationship between the laser oscillation wavelength, the threshold, and the Ga concentration d of the substitutional garnet crystal material for solid-state laser of the example.

FIG. 7: Composition formula Y _3-abcv La _v Nd _a Lu _b Ca _c Al
_5-de Ga _d Mg _e O ₁₂ (a = 0.13, b = 0.80,
c = 0.2, d = 1.0, e = 0.6). The relationship between the laser oscillation wavelength, the threshold, and the La concentration V of the substitutional garnet crystal material for a solid-state laser of Example 1-10 represented by FIG.

[8] the composition formula _{Y 3-XY Nd X Yb Y} Al 5-Z Ga Z O
_The figure which shows the laser oscillation wavelength of the substitutional garnet crystal material for solid-state lasers of the Example represented by ₁₂ (X = 0.1, Y = 1.0), the threshold value, and Ga concentration Z.

FIG. 9: Compositional formula Gd _3-XY Nd _X Yb _Y Al _5-ZW Ga _Z S
c _W O ₁₂ (X = 0.13, Y = 1.2, W = 2.00)
The figure which shows the laser oscillation wavelength of the substitutional garnet crystal material for solid-state lasers of the Example represented by, and the relationship of threshold value and Ga concentration Z.

FIG. 10: Composition formula Y _3-XYV La _V Nd _X Yb _Y Al _5-Z G
a _Z O ₁₂ (X = 0.13, Y = 1.00, Z = 0.1
7] A diagram showing the relationship between the laser oscillation wavelength, the threshold value, and the La concentration V of the substitutional garnet crystal material for a solid-state laser of Example 1-15 represented by 7).

FIG. 11 is a perspective view of an optical waveguide having a core made of a garnet crystal material for laser.

FIG. 12 is a diagram showing a measurement system for evaluating the characteristics of an optical waveguide having a core made of a substitutional garnet crystal material for a solid-state laser as a waveguide type laser.

FIG. 13 is a diagram showing an energy diagram of praseodymium.

FIG. 14 is a diagram showing a relationship between a Ga concentration Z, a laser oscillation wavelength, and an oscillation threshold value.

FIG. 15 is a diagram showing a relationship between a Ga concentration Z, a laser oscillation wavelength, and an oscillation threshold value.

[Explanation of symbols]

1 semiconductor laser 2 lens 3 excitation light 4 disk made of substitutional garnet crystal material for solid-state laser 5 emission light 6 optical spectrum analyzer 7 optical fiber 8 optical waveguide having core made of substitutional garnet crystal material 9 substrate 10 core 11 clad 12 Light entrance / exit end

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Yamada 1-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation (72) In-house Yasushi Oishi 1-1-6 Uchiyuki-cho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Makoto Shimizu 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Shoichi Sudo 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (10)

[Claims] 1. A general formula is represented by R ₃ A ₅ O ₁₂ , wherein R is yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, Substitutional garnet consisting of any combination of one or more elements selected from bismuth, and A consisting of any combination of one or more elements selected from aluminum, scandium and gallium A substitutional garnet crystal material for a solid-state laser, wherein the crystal contains at least neodymium, lutetium, and gallium as its constituent elements. 2. A general formula is represented by R ₃ A ₅ O ₁₂ , wherein R is yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, Substitutional garnet consisting of any combination of one or more elements selected from bismuth, and A consisting of any combination of one or more elements selected from aluminum, scandium and gallium A substitutional garnet crystal material for a solid-state laser, characterized in that the crystal contains at least neodymium and lutetium as its constituent elements. 3. Occupancy rate of neodymium is 1% of all rare earth elements.
The above is the occupancy rate of lutetium to 3 of all rare earth elements.
The substitution type garnet crystal material for a solid-state laser according to claim 1 or 2, which is 0% or less. 4. The substitutional garnet crystal material for a solid-state laser according to claim 1, wherein one or both of calcium and magnesium are added. 5. The substitutional garnet crystal material for a solid-state laser according to claim 4, wherein the added amount of calcium and / or magnesium is the same as that of lutetium. 6. A substitutional garnet crystal for a solid-state laser according to claim 1, wherein one or more elements selected from lanthanum, gadolinium and yttrium are arbitrarily combined as R. material. 7. A general formula is represented by R ₃ A ₅ O ₁₂ , wherein R is yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, Substitutional garnet consisting of any combination of one or more elements selected from bismuth, and A consisting of any combination of one or more elements selected from aluminum, scandium and gallium A substitutional garnet crystal material for a solid-state laser, characterized in that the crystal contains at least neodymium, ytterbium, and gallium as its constituent elements. 8. A general formula is represented by R ₃ A ₅ O ₁₂ , wherein R is yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, Substitutional garnet consisting of any combination of one or more elements selected from bismuth, and A consisting of any combination of one or more elements selected from aluminum, scandium and gallium A substitutional garnet crystal material for a solid-state laser, characterized in that the crystal contains at least neodymium and ytterbium as its constituent elements. 9. The occupancy rate of neodymium is 1% of all rare earth elements.
It is above, and the occupancy rate of ytterbium is 40% or less of the whole rare earth element, It is characterized by the above-mentioned.
A substitutional garnet crystal material for a solid-state laser according to claim 1. 10. The substitutional garnet crystal for a solid-state laser according to claim 7, wherein R is an arbitrary combination of one or more elements selected from lanthanum, gadolinium and yttrium. material.