JPH07101749A - Chalcogenide glass - Google Patents

Abstract

PURPOSE:To provide a glass capable of the addition of rare earth elements by improving the composition of the conventional chalcogenide glass. CONSTITUTION:In a Ge based or Ge-As based chalcogenide glass, the composition except rare earth elements is 0<A2-xSaSeb or As2-xSaSeb+A2-xSa'Seb'<75(mol%), 25<GeSa'Seb'<100(mol%) (where, 1<=a+b<=5, 1<=a'+b'<=5, -0.2<=x<=1.5, A is one or two kinds selected from a group of Al, Ga, Tl, In, Sb and Bi) and is in the range of A2-xSaSeb+GeSa'Seb=100mol%. As a result, a rare earth adding glass using the chalcogenide glass small in lattice vibration energy as a matrix is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to chalcogenide glass, and more particularly to chalcogenide optical fiber materials for rare-earth element-doped optical fiber lasers or optical fiber amplifiers.

[0002]

2. Description of the Related Art In recent years, research and development of optical fiber lasers and optical fiber amplifiers in which rare earth ions are added to the core of an optical fiber have been actively conducted. This is a rare earth ion 4
It utilizes the stimulated emission transition due to the transition in the f shell,
Rare earth doped quartz fibers and fluoride fibers have been used as amplification media. The quantum efficiency of stimulated emission due to the transition in the 4f shell is determined by the energy interval between the energy level of the laser energy level and the energy level located immediately below the energy level. This is due to the emission of multitones due to the lattice vibration of the base material to which the rare earth element is added. That is, when the energy interval is narrow, the multi-tone emission occurs. That is, if the energy interval is narrow, relaxation due to the non-axial radiation transition from the laser initial level to the level immediately below due to multi-phonon emission is likely to occur and the quantum efficiency decreases. In order to improve the quantum efficiency with low quantum efficiency due to the relaxation of multi-phonon emission as described above, a matrix with low lattice vibration energy may be used as a matrix to which rare earths are added.

Chalcogenide glass is known as a fiber material having low lattice vibration energy. The lattice vibration energy of chalcogenide glass is 300 to 400 cm.
^-1, which is the lattice vibration energy of quartz glass (1100
cm ^-1 ) has a value close to one-third to one-quarter, and compared with fluoride glass (500 cm ^-1 ) it is about 20% to 70% smaller. It can be said that this fiber material is suitable for increasing the quantum efficiency of transitions with low quantum efficiency due to relaxation of child emission.

However, the solubility of rare earths in AsS-based glass and GeS-based glass, which have been known as fiber-forming materials, is low, and the chalcogenide glass fiber doped with rare earths has not yet been obtained.

[0005]

OBJECTS OF THE INVENTION It is an object of the present invention to improve the composition of conventional chalcogenide glass, realize a glass to which a rare earth element can be added, and to provide a rare earth-added chalcogenide optical fiber.

[0006]

In order to solve the above problems, the rare earth-doped chalcogenide glass according to the present invention uses S and Se elements as anions, Ge as cations, and Al, Ga, and Tl. , in, Sb, in chalcogenide glass containing at least one or more of one or two elements and rare earth elements Bi, the composition excluding the rare earth element is _{0 <a 2-X S a} Se b ≦ 75 ( mol% 25 ≦ GeS _{a ′} Se _{b ′} ≦ 100 (mol%) (where 1 ≦ a + b ≦ 5, 1 ≦ a ′ + b ′ ≦ 5, −0.
2 ≦ x ≦ 1.5, A is Al, Ga, Tl, In, S
b, one or two selected from the group of Bi),
A _2−X S _a Se _b + GeS _{a ′} Se _{b ′} = 100 mol%.

Further, the chalcogenide glass according to the present invention uses S and Se elements as anions, Ge and As as cations, and Al, Ga, Tl, In, Sb and Bi.
In any element and including at least one or more rare earth elements chalcogenide glass, the glass component Ge excluding the rare earth elements, As, S, Se, the proportion of A is _{0 <As 2-X S a} Se b + A 2 _{-X Sa '} Se _b' ≤ 75 (mol%) 25 ≤ GeS _{a "} Se _b" ≤ 100 (mol%) (where 1 ≤ a + b ≤ 5, 1 ≤ a '+ b' ≤ 5, 1 ≤
a ″ + b ″ ≦ 5, −0.2 ≦ x ≦ 1.5, A is Al,
Ga, Tl, In, Sb, or Bi), and A
_{s 2-X S a Se b} + A 2-X S a 'Se b' + GeS a "Se b" + =
It is characterized by being in the range of 100 mol%.

That is, the present invention is based on As-S system, Ge-
S, Ge—S—Se chalcogenide glass or a mixed glass of two or more of these glasses is used as In, G
a, Sb, Al, Tl, III b group on the periodic table such as Bi,
The main feature is to add a _Vb group element.

Conventional As-S system, Ge-S system, Ge-S
The solubility of rare earth elements in chalcogenide glass such as -Se system is low, and when rare earth elements are added to these glasses, there is a drawback that precipitation of rare earth elements or crystallization with the precipitation phase as a nucleus occurs, and transparent glass is difficult to obtain. . But III
_b group, or V and _b elements of group can increase the solubility of the rare earth element into the chalcogenide glass in by adding a glass component, the glass material was obtained for permeability good fiber. This, III _b group, a sulfide of V _b group Ln ³⁺
When (Ln: rare earth) is added, III _b group, V _{b in the} glass
S ^2- ions occurs without a covalent bond with group element, AS ₄ suitable for glass formation: potential energy (A III _b or Group V _b group element) structure and rare earth (Ln ³⁺⁾ is reduced Ion sites are formed at the same time. Accordingly, III _b group, or V _b group of sulfides as well as stabilizing the glass when added to the above chalcogenide glass, so that the solubility of the rare earth is increased. Further, according to the present invention, it has become possible to produce a rare-earth-doped chalcogenide glass excellent in thermal stability, which has not been heretofore known, by a melting method suitable for mass production.

In the above-mentioned first invention of the present invention, A
Can be one or two selected from the group consisting of Al, Ga, Tl, In, Sb and Bi, and the ratio thereof is 0.
<A _{2- X} S _a Se _b ≦ 75 (mol%) (hence 25 ≦
GeS _{a ′} Se _{b ′} ≦ 100 mol%). A _2-X S _a Se
_{This is because if b} exceeds 75 mol%, it may be difficult to vitrify, as will be apparent from the examples described later. Further, the range is −0.2 ≦ x ≦ 1.5. If it deviates from this range, the stability of the whole glass will be deteriorated.

The ratio of S and Se is 1≤a + b≤5,
1 ≦ a ′ + b ′ ≦ 5, but if deviating from this range,
Similarly, the stability of the overall glass may be compromised.

In the second invention of the present invention, G
The present invention is intended for e-As type glass, and in the present invention, A is Al, Ga, Tl, In, Sb, Bi.
Can be any of, the ratio is 0 in relation to the _{As <As 2-X S a} Se b + A 2-X S a 'Se b' ≦ 7
5 (mol%) (hence 25 ≦ GeS _{a ′} Se _{b ′} ≦ 10
0 mol%). _{As 2-X S a Se b} + A 2-X S a 'Se b'
Is more than 75 mol%, vitrification tends to be difficult, as will be apparent from the examples described later. Further, the range is −0.2 ≦ x ≦ 1.5. If it deviates from this range, the stability of the whole glass will be deteriorated.

The ratio of S and Se is 1≤a + b≤5,
1 ≦ a ′ + b ′ ≦ 5, 1 ≦ a ″ + b ″ ≦ 5, but if it deviates from this range, the stability of the entire glass may be similarly deteriorated.

As rare earth elements, La, Pr, Ce,
Nd, Sm, Eu, Gd, Tb, Gd, Dy, Er, H
One or more of o, Tm, and Yb can be mentioned.

[0015]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples.

[0016]

Example 1 0 <A _2-X S _a Se _b ≦ 75 (mol%) 25 ≦ GeS _{a ′} Se _{b ′} ≦ 100 (mol%) (1 ≦ a + b ≦ 5, 1 ≦ a ′ + b ′ ≦ 5, -0.
2 ≦ x ≦ 1.5, A is Al, Ga, Tl, In, S
b or Bi) (total of each component is 100 mol%)

Pr ₂ S ₃ was added to the raw material mixed in the composition range of (1), and the mixture was melted in a quartz ampoule at 1000 ° C. for 4 hours.
A quartz ampoule was allowed to cool in air to produce glass. P
When the added amount (c) of r was 0 <c ≦ 1% by weight, a glass with high uniformity was obtained.

PrCl ₃ and P are used as raw materials for adding Pr.
It was also possible to vitrify using rBr ₃ and PrI ₃ . Further, as the rare earth element, in addition to Pr, Ce, N
d, Sm, Eu, Tb, Gd, Dy, Er, Ho, T
Even when m and Yb were added in the range of 0 <c ≦ 1 (c: the amount of rare earth element added, the same applies hereinafter), transparent glass could be obtained.

[0019]

[Example 2] Sb ₂ S ₃ (20) -GeS _2.5 (80 mol%) was used as a core glass, Pr was added at 500 ppm, and S was added.
Using b ₂ S ₃ (10) -GeS _2.5 (90 mol%) as a cladding glass, a single-mode optical fiber was prepared by a crucible drawing method, and an optical amplification experiment at 1.31 μm was performed. 20 at (wavelength 1.02 μm)
A gain of dB was obtained.

As described in Embodiment 1, instead of Sb, A
l. Even if Tl, In, Ga, Bi or the like was used as the glass component, the fiber could be produced in the composition range described in Example 1, and the gain could be confirmed.

[0021]

Example 3 A single mode fiber was manufactured by adding Dy in place of Pr in Example 2 and pumped at a wavelength of 1.09 μm. When pumping 100 mW, a gain of 10 dB was obtained at 1.34 μm.

[0022]

Fourth Embodiment 0 <(Ga ₂ S ₃ + Sb ₂ S ₃ ) or (Sb
₂ S ₃ + In ₂ S ₃ ) or (In ₂ S ₃ + Ga ₂ S ₃ ) or (Sb ₂ S ₃ + Al ₂ S ₃ ) or (Ga ₂ S ₃ + Al ₂ S ₃ )
Or (In ₂ S ₃ + Al ₂ S ₃ ) or (Sb ₂ S ₃ + Tl
₂ S ₃ ) or (Ga ₂ S ₃ + Tl ₂ S ₃ ) or (Ga ₂ S ₃
+ Tl ₂ S ₃ ) or (In ₂ S ₃ + Tl ₂ S ₃ ) or (S
b ₂ S ₃ + Bi ₂ S ₃ ) or (Sb ₂ S ₃ + Ga ₂ S ₃ ) or (In ₂ S ₃ + Bi ₂ S ₃ ) ≦ 75 (mol%)

25 ≦ GeS _{a ′} ≦ 100 (mol%) (1
≦ a ′ ≦ 5)

Pr ₂ S ₃ was added to the raw materials mixed in the composition range (total of each component was 100 mol%), and the mixture was melted in a quartz ampule at 1000 ° C. for 4 hours, and then the quartz ampule was allowed to cool in air. To produce glass. The amount of Pr added (c) is
When 0 <c ≦ 1% by weight, a glass with high uniformity was obtained.

As a raw material for adding Pr, PrCl ₃ , P
It was also possible to vitrify using rBr ₃ and PrI ₃ . Further, as the rare earth element, in addition to Pr, La, C
e, Nd, Sm, Eu, Tb, Gd, Dy, Er, H
Even when 0, Tm and Yb were added in the range of 0 <c ≦ 1, transparent glass could be obtained.

[0026]

Example 5 Sb ₂ S ₃ (10) -Ga ₂ S ₃ (10) -G
eS _2.5 (80 mol%) as the core glass and Pr of 50
0 ppm added, Sb ₂ S ₃ (10) -GeS _2.5 (90
(Mol%) as the cladding glass, a single-mode optical fiber was produced by the crucible drawing method, and an optical amplification experiment at 1.31 μm was performed. A gain of 20 dB was obtained with 20 mW of pumping light (wavelength 1.02 μm). Was given.

As described in Example 4, the components other than GeS _{a '} are (Sb ₂ S ₃ + In ₂ S ₃ ), (In ₂ S ₃ + G
a ₂ S ₃ ), (Sb ₂ S ₃ + Al ₂ S ₃ ), (Ga ₂ S ₃ + Al
₂ S ₃ ), (In ₂ S ₃ + Al ₂ S ₃ ), (Sb ₂ S ₃ + Tl ₂
S ₃ ), (Ga ₂ S ₃ + Tl ₂ S ₃ ), (In ₂ S ₃ + Tl ₂ S
₃ ), (Sb ₂ S ₃ + Bi ₂ S ₃ ), (Sb ₂ S ₃ + Bi
₂ S _3), be added as a glass component _{(In 2 S 3 + Bi 2} S 3), the fiber is capable of producing in the composition range described in Example 4, it was possible to check the gain.

[0028]

Sixth Embodiment In the first embodiment, G is replaced by Gs instead of GeS _{a ′.}
using the eS _{a 'Se b',}

0 <A _2-X S _a Se _b ≦ 75 (mol%) 25 ≦ GeS _{a ′} Se _{b ′} ≦ 100 (mol%) (where 1 ≦ a + b ≦ 5, 1 ≦ a ′ + b ′ ≦ 5, -0.
2 ≦ x ≦ 1.5, A is Al, Ga, Tl, In, S
b or Bi)

Pr ₂ S ₃ was added to the raw materials mixed in the composition range (total of each component was 100 mol%) and melted in a quartz ampule at 1000 ° C. for 4 hours, and then the quartz ampule was allowed to cool in air. To produce glass. Pr addition amount (c) is 0
A glass having a high degree of uniformity was obtained when <c ≦ 1% by weight.

As a raw material for adding Pr, PrCl ₃ , P
It was also possible to vitrify using rBr ₃ and PrI ₃ . Further, as the rare earth element, in addition to Pr, La, C
e, Nd, Sm, Eu, Tb, Gd, Dy, Er, H
Even when 0, Tm and Yb were added in the range of 0 <c ≦ 1, transparent glass could be obtained.

[0032]

Example 7 Ga ₂ S ₃ (20) -GeS _3.5 Se _0.5 (8
0 mol%) was used as the core glass and Pr was added at 500 ppm, and Ga ₂ S ₃ (10) -GeS _3.5 Se _0.5 (90 mol%) was used as the cladding glass to prepare a single mode optical fiber by the crucible drawing method. When an optical amplification experiment was performed at 31 μm, the pumping light was 20 mW (wavelength 1.02 μm).
A gain of 20 dB was obtained in m).

As described in Example 6, even if Al, Tl, In, Sb, Br or the like is used as the glass component instead of Ga, the fiber can be produced in the composition range described in Example 6, and the gain can be improved. I was able to confirm.

[0034]

Example 8 0 <(As ₂ S ₃ + Al ₂ S ₃ ) or (As
₂ S ₃ + Ga ₂ S ₃ ) or (As ₂ S ₃ + Tl ₂ S ₃ ) or (As ₂ + In ₂ S ₃ ) or (As ₂ S ₃ + Sb ₂ S ₃ ) or (As ₂ S ₃ + Bi ₂ S ₃ ) ≤75 (mol%)

25≤GeS _{a "} or Ge (S _a" Se _{b "} )
x ≦ 100 (mol%) (1 ≦ a ″ or a ″ + b ″ ≦
5)

Pr ₂ S ₃ was added to the raw materials mixed in the composition range (100 mol% in total of each component), and the mixture was melted in a quartz ampule at 1000 ° C. for 4 hours, and then the quartz ampule was allowed to cool in air. To produce glass. The amount of Pr added (c) is
When 0 <c ≦ 1% by weight, a glass with high uniformity was obtained.

PrCl ₃ and P are added as raw materials for addition of Pr.
It was possible to vitrify using rBr ₃ and PrI ₃ .
Further, as the rare earth element, other than Pr, La, Ce, N
d, Sm, Eu, Tb, Gd, Dy, Er, Ho, T
A transparent glass could be obtained even when 0 <c ≦ 1 was added to m and Yb.

Although the rare earth addition concentration is set to 1% by weight or less in the above examples, the concentration is not limited to this. That is, if the glass is melted and then rapidly cooled, it is possible to add 1% by weight or more of a rare earth element.

The glass obtained by adding 500 ppm of Pr to the chalcogenide glass described in Examples 1, ₄ , 6 and 8 was used as the core glass, and the cladding glass was ZrF ₄ type fluoride glass (“Fluoride glass fiber optics” l. Aggarwal).
Edit Academic Press 1991), phosphate glass or lead glass (edited by "Glass Handbook" by Sakuhana et al., Asakura Shoten, 1975), or chalcogenide glass as the cladding glass by the rod-in-tube method.
A μm fiber was prepared. When optical amplification in the 1.3 μm band was performed using this fiber 20 m as an amplification fiber, a signal benefit of 20 dB or more could be obtained with 20 mW of pumping light of 1.02 μm.

Ce (5 μm laser oscillation), Nd (1.08 μm, 1.38 μm, 2.5 μ) instead of Pr
m, 5 μm laser oscillation), Sm (0.59 μm laser oscillation), Eu (0.61 μm laser oscillation), Tb
(Laser oscillation of 0.54 μm), Dy (3 μm, 4.2)
μm laser oscillation), Ho (2 μm laser oscillation), E
r (1.5 μm, 2.7 μm laser oscillation), Tm
(1.9 μm, 2.2 μm laser oscillation), Yb (1 μm
m laser oscillation), Dy (1.34 μm) -added chalcogenide glass as a core, and a fiber laser and a fiber amplifier that oscillate at each wavelength could be constructed.

[0041]

Example 9 As ₂ S ₃ (20) -Al ₂ S ₃ (3) -Ge
Pr of 500 p with S ₂ (77 mol%) as the core glass
pm added, As ₂ S ₃ (10) -Al ₂ S ₃ (3) -Ge
A single mode optical fiber was produced by a crucible drawing method using S ₂ (87 mol%) as a cladding glass, and 1.31 μ
When an optical amplification experiment was conducted at m, the pumping light was 20 mW.
A gain of 20 dB was obtained at (wavelength 1.02 μm).

As described in Example 6, even if Al, Tl, In, Sb, Br or the like is used as the glass component instead of Ga, the fiber can be produced in the composition range described in Example 6, and the gain is increased. was gotten.

As described in Example 8, (As ₂ S ₃ + G
a ₂ S ₃ ), (As ₂ S ₃ + Tl ₂ S ₃ ), (As ₂ S ₃ + In
₂ S ₃ ), (As ₂ S ₃ + Sb ₂ S ₃ ), (As ₂ S ₃ + Bi ₂
Even if S ₃ ) was added as a glass component, the fiber could be produced in the composition range described in Example 8, and the gain could be confirmed.

In the composition region described in Examples 1, 4, 6, and 8, the critical cooling rate (reference: JM Barandiaran and J.
Colmenero J. Non-Cryst. Sobds. Vol. 46 (1981) p.2
77) (the smaller the more stable the glass is), 3
It becomes 00 K / min and can be used as fiber glass. However, in the outer composition region, 300K /
It becomes more than min, and it becomes difficult to use as fiber glass.

Therefore, when the host of the fiber amplifier or the fiber laser is used, the first, fourth, sixth and eighth embodiments are used.
The compositional range mentioned in 1. is suitable.

[0046]

As described above, according to the present invention, it is possible to provide a rare earth-doped glass having a chalcogenide glass having a small lattice vibration energy as a matrix, and using this glass as a core material of a rare earth-doped optical fiber,
It is possible to construct a highly efficient fiber laser or fiber amplifier in which the quantum effect of the transition in the 4f shell of the rare earth element is dramatically enhanced. Among the rare earth elements, if chalcogenide glass doped with Pr is used as the core material, the quantum efficiency will be 10 times higher than that of Pr-doped fiber currently used as a fiber for 1.3 μm melted optical fiber amplifier in the future. As described above, there is an advantage that a high Pr-doped fiber can be obtained and a highly efficient 1.3 μm band optical fiber amplifier can be configured.

In addition to the optical fiber amplifier, the use of chalcogenide glass doped with Tm, Er, etc. has the advantage that a highly efficient up-conversion fiber laser can be constructed.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoichi Sudo 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (2)

[Claims] 1. An S and Se element as an anion, a Ge as a cation, and at least one element selected from the group consisting of Al, Ga, Tl, In, Sb, and Bi, and at least one of rare earth elements. In the chalcogenide glass, the composition excluding the rare earth element is 0 <A _2-X S _a Se _b ≦ 75 (mol%) 25 ≦ GeS _{a ′} Se _{b ′} ≦ 100 (mol%) (where 1 ≦ a + b ≦ 5, 1 ≦ a ′ + b ′ ≦ 5, −0.
2 ≦ x ≦ 1.5, A is Al, Ga, Tl, In, S
b, one or two selected from the group of Bi),
A chalcogenide glass characterized by being in a range of A _2−x S _a Se _b + GeS _{a ′} Se _{b ′} = 100 mol%. 2. S and Se elements as anions, Ge and As as cations, and Al, Ga, Tl, In,
In the chalcogenide glass containing any one element of Sb and Bi and at least one kind of rare earth element, the ratio of the glass components Ge, As, S, Se and A excluding the rare earth element is 0 <As _{2-X Sa} Se _b + A _2−x S _{a ′} Se _{b ′} ≦ 75 (mol%) 25 ≦ GeS _{a ”} Se _b” ≦ 100 (mol%) (1 ≦ a + b ≦ 5, 1 ≦ a ′ + b ′ ≦ 5, 1 ≤
a ″ + b ″ ≦ 5, −0.2 ≦ x ≦ 1.5, A is Al,
Ga, Tl, In, Sb, or Bi), and A
_{s 2-X S a Se b} + A 2-X S a 'Se b' + GeS a "Se b" + =
A chalcogenide glass characterized by being in a range of 100 mol%. And As _2-X S _a Se _b + A _2-X S
_{a 'Se b' + GeS a} "Se b" = chalcogenide glass, characterized in that in the 100 mol% and comprised within the range.