JP2001358391A - Optical fiber module for optical amplification - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent loss increase and gain decrease due to high power pumping, in an optical fiber module for optical amplification which module has a connection part using UV-curing resin. SOLUTION: Core glass is doped with Ce which absorbs an up-conversion light of ultraviolet wavelength generated from light emitting ions by incidence of a pumping light for amplification.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a 1.3 μm band, a 1.4 μm band, and a 1.5 μm band used in an optical communication system or the like.
The present invention relates to an optical fiber module for optical amplification used in an m-band optical fiber amplifier, and particularly to a highly reliable optical fiber module for optical amplification that does not cause deterioration in characteristics at high power excitation.

[0002]

2. Description of the Related Art An optical fiber amplifier doped with rare earth ions of Pr, Tm, and Er as light-emitting ions has a high gain, an amplification characteristic independent of polarization, a low noise figure, and a wide wavelength characteristic. Therefore, it is a key device for realizing large capacity and high functionality of an optical communication system. Up to now, a 1.3 μm band optical fiber amplifier using a fluoride optical fiber or a sulfide optical fiber doped with Pr ions in the core, and a 1.4 μm band using a fluoride optical fiber doped with Tm ions in the core. An optical fiber amplifier for 1.5 μm band using a quartz optical fiber having a core doped with Er ions, a fluoride optical fiber, and a tellurite optical fiber has been developed. These optical fiber amplifiers basically consist of an optical fiber module consisting of an amplification optical fiber with light-emitting ions added to the core and a transmission silica optical fiber connected to both ends of the amplifier, a light source for excitation, a coupler, and an isolator. You. Connecting both ends of an amplification optical fiber having a core to which light-emitting ions are added to a transmission silica optical fiber is an indispensable element for use in an optical communication system constructed of a silica fiber.

[0003] In this connection, a fused optical fiber, which is a general method of connecting a quartz optical fiber, is used because a quartz optical fiber having a core doped with luminescent ions is made of the same material as the quartz optical fiber for transmission. Although it is possible, the fusion method cannot be applied because the glass system is different in other cases. Therefore, a method is used in which the fiber is fixed to a V-groove or a ferrule, and the fiber end faces are aligned and connected. In these V-groove connections and ferrule connections, a method of bonding the fiber end faces using a UV curable resin is generally employed to reduce the reflection loss at the connection portion and prevent displacement.

[0004]

The optical fiber amplifier constructed as described above generally shows good amplification characteristics, but the present inventors have found that some amplifiers have deteriorated amplification characteristics due to high power excitation of 500 mW or more. I found the problem of doing. That is, fluoride optical fiber, sulfide optical fiber,
It was also found that irreversible loss of gain was caused by high power pumping in an optical amplifier using tellurite optical fiber as an amplification medium.

An object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide a highly reliable optical fiber module for optical amplification without deterioration of characteristics in high power pumping.

[0006]

Generally, light emission is caused by the emission ions receiving the energy of the excitation light to enter a high energy state and then emitting light to transition to a low energy state. However, the light-emitting ions that have received the energy of the excitation light and are in a high energy state further receive the energy of the excitation light, have a higher energy state, and have a shorter wavelength than the wavelength of the excitation light, that is, May emit up-conversion light.

The present inventors believe that the deterioration of the amplification characteristics is caused by an increase in optical loss of the optical fiber module, and the increase in the loss is caused by the connection using the UV-curable resin on the side where the excitation light is incident. I found what would happen.

[0008] This is because on the side where the excitation light is incident, the up-conversion light of the ultraviolet wavelength generated from the light-emitting ions is strongly emitted from the end face of the amplifying fiber. Increases, suggesting that a gain reduction occurs. On the other hand, on the side where the excitation light is not incident, the intensity of the excitation light decreases due to the absorption of the light-emitting ions, so that the generation of the up-conversion light of the ultraviolet wavelength is weakened, and it is considered that the UV curable resin of the connection portion does not deteriorate. The present invention has been made based on these findings.

A first embodiment of the present invention comprises an amplifying optical fiber having a core and a clad, a core glass containing luminescent ions, and a quartz optical fiber connected to both ends of the amplifying optical fiber. In an optical amplification optical fiber module in which a connection end face of an optical fiber and a quartz optical fiber is bonded using a UV curing resin, the amplification optical fiber is Ce.
Characterized by comprising a core glass to which is added.

[0010] In a second embodiment of the present invention, the optical fiber module for optical amplification is characterized in that the glass matrix of the optical fiber for amplification to which Ce is added is made of fluoride glass.

In a third embodiment of the present invention, in the optical fiber module for optical amplification, a part of fluorine of the fluoride glass constituting the optical fiber for amplification is chlorine;
It is characterized by being substituted by at least one selected from the group consisting of bromine and iodine.

[0012] In a fourth embodiment of the present invention, the optical fiber module for optical amplification is characterized in that the glass matrix of the optical fiber for amplification to which Ce is added is made of sulfide glass.

In a fifth embodiment of the present invention, in the optical fiber module for optical amplification, a part of sulfur of the sulfide glass constituting the optical fiber for amplification is composed of oxygen, chlorine, bromine, and iodine. It is characterized by being substituted by at least one member selected from the group.

In a sixth embodiment of the present invention, the optical fiber module for optical amplification is characterized in that the glass matrix of the optical fiber for amplification to which Ce is added is made of tellurite glass.

In a seventh embodiment of the present invention, in the optical fiber module for optical amplification, the luminescent ions are P
It is characterized by being at least one selected from the group consisting of r, Tm, Er, Dy, Yb, Nd, and Ho.

In the present invention, the amplification optical fiber is C
By using the core glass to which e is added, the generation of up-conversion light having an ultraviolet wavelength can be suppressed, so that the UV curable resin at the connection portion does not deteriorate, thereby preventing an increase in module loss and a decrease in gain.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The optical fiber module for optical amplification according to the present invention can use a fluoride fiber, a sulfide fiber, or a tellurite fiber as an amplification optical fiber.

The fluoride fiber according to the present invention comprises:
(1) ZrF_FourAnd HfF_FourLess selected from the group consisting of
45 to 65 mol%, SrF_Two, BaF_Two, P
bF_TwoAre respectively 0 to 10 mol%, 5 to 35 mol
%, 0 to 25 mol% (however, BaF_Two+ SrF_Two+ Pb
F_TwoIs 15 to 35 mol%), LaF_Three, Gd
F_Three, LuF_ThreeIn each of 0 to 10 mol%, AlF_Three,
ScF_Three, YF_Three, GaF_Three, InF_ThreeEach from 0 to 8m
ol%, LiF, NaF, KF, RbF, CsF
Each contains 0 to 25 mol%, and the total is 100 mo
1% ZrF_Four/ HfF_FourFluoride glass, (2)
InF_ThreeFrom 5 to 35 mol%, GaF_Three5 to 35 mol
%, ZnF_Two5-20 mol%, BaF_Two0 to 25m
ol%, SrF_TwoFrom 0 to 15 mol%, PbF_Two0 to 4
5 mol%, CdF_TwoFrom 0 to 10 mol%, AlF_Three, S
cF_Three, YF_Three, LaF_Three, GdF_Three, LuF_ThreeGroup consisting of
1.5 to 10 mol% of at least one selected from the group consisting of:
LiF, NaF, KF, RbF, CsF are each 0 to
30 mol%, and the total is 100 mol%
InF_Three/ GaF_ThreeFluoride glass or (3)
AlF_Three20 to 50 mol%, CaF_Two, SrF_Two, B
aF_Two, PbF_TwoAt least one selected from the group consisting of
20 to 50 mol%, MgF_Two, ZnF_TwoTo 0
~ 25mol%, YF_Three5 to 30 mol%, ScF_Three,
LaF_Three, GdF_Three, LuF_Three, GaF_Three, InF_ThreeIt
0-15 mol% each, ZrF_Four, HfF_FourTo 0
~ 20mol%, LiF, NaF, KF, RbF, Cs
F in each of 0 to 15 mol%, and the total is 1
AlF which is 00mol% _ThreeComposed of fluoride glass
can do.

Further, a part of the fluorine in the above-mentioned fluoride glass component is replaced with at least one of chlorine, bromine and iodine.
Glass substituted by species can also be used.

In the present invention, the sulfide fiber is Ga ₂
S ₃ a 50~75mol%, 0~40mol the La ₂ S _{3
%, Li 2 S, Na 2} S, K 2 S, Rb 2 S, Cs 2 S hints respectively 0~40mol%, and the total is 100m that
ol% of Ga ₂ S ₃ sulfide glass.

Further, a glass in which a part of sulfur in the above-mentioned sulfide glass component is replaced by at least one of oxygen, chlorine, bromine and iodine can also be used.

The tellurite fiber according to the present invention has a T
eO ₂ The 55~90mol%, 0~20mo the Bi ₂ O ₃
1%, ZnO of 0 to 35 mol%, Li ₂ O, Na ₂ O,
K ₂ O, Rb ₂ O, and Cs ₂ O each in an amount of 0 to 35 mol
%, 0 to ₃ mol% of Al ₂ O ₃ system, and a total of 1
It can be made of a TeO ₂ -based tellurite glass that is 00 mol%.

The amount of Ce added to the core of the optical fiber for optical amplification of the present invention is more than 0 wt%, preferably 0.05 wt% or more and 30 wt% or less, more preferably 0.1 wt% or more and 20 wt%. The content is more preferably 0.5% or more and 10% by weight or less.

As the light-emitting ions added to the core of the amplification optical fiber constituting the optical amplification optical fiber module of the present invention, one kind selected from the group consisting of Pr, Tm and Er can be used. . The addition of Ce according to the present invention does not increase the optical loss in the optical communication wavelength band of the optical fiber module for optical amplification. Thereby, the 1.3 μm band and 1.4 μm of the low loss wavelength region of the quartz optical fiber for transmission are used.
A highly reliable optical amplifier that can be used in the m band and the 1.5 μm band can be realized.

The present invention can also be applied to an optical fiber module for optical amplification constituted by using other light-emitting ions which easily emit up-conversion light having an ultraviolet wavelength similar to the above-mentioned light-emitting ions. This includes Dy, Yb, N
There are light-emitting ions of d and Ho, and the same effect can be obtained in these co-added systems containing at least one selected from the group consisting of Pr, Tm, Er, Dy, Yb, Nd and Ho. be able to.

Hereinafter, the present invention will be described in detail with reference to specific examples, but the present invention is not limited thereto.

[0027]

FIG. 1 is a schematic view of an optical fiber module for optical amplification according to the present invention. a is an optical fiber for amplification. The quartz optical fiber 1b has the same relative refractive index difference Δn as the amplification optical fiber in order to reduce the connection loss. Further, c is a quartz optical fiber 2 having Δn used in the communication system. The amplifying optical fiber a and the quartz optical fiber 1 b are V-groove connected at d. At the V-groove connection portion, the fiber end face is obliquely polished to reduce the reflection loss, and bonded using a UV curing resin to connect the fibers. Since the quartz optical fiber 1 of b and the quartz optical fiber 2 of c have different Δn, a low-loss connection is made at e using the core expansion fusion splicing method.

FIG. 2A shows an amplification optical fiber.
Add 2000ppm Tm and 3wt% Ce to the core
Fiber module for optical amplification using fluorinated fiber
6 shows the results of measuring the change over time in the gain of the rule. Tm and C
Fluoride fiber core and cladding doped with e
The mother phase is 57ZrF each_Four-15.5BaF_Two-12.
5PbF_Two-3.5LaF_Three-2YF_Three-2AlF_Three-0.
5InF_Three-7LiF, 47.5ZrF_Four-23.5Ba
F_Two-2.5LaF_Three-2YF_Three-4.5 AlF _Three-20N
aF (mol%), Δn is 3.7%, cut-off
Wavelength 1.0 μm, loss is 50 dB / km (wavelength 1.4
μm), the outer diameter was 125 μm, and the length was 20 m. excitation
Nd: YLF laser with wavelength of 1.047 μm is used as the light source
500 mW incident from the front, wavelength 1.471μ
The signal light having a light intensity of -20 dBm was amplified. FIG.
As is clear from (1), the time of the gain even after 20 hours
No change occurred. FIG. 3 shows (1) and 2
Optical loss spectrum of optical fiber module after time (2)
It is. Loss remained almost unchanged.

(Comparative Example 1) In the same amplifying optical fiber module configuration as in Example 1, using an amplifying optical fiber in which Ce is not added to the core, the change over time of the gain was performed under the same conditions as in Example 1. It was measured. Each core, a cladding matrix fluoride fiber amplifying optical fiber added with Tm of 2000ppm in the core using 57ZrF ₄ -
15.5BaF ₂ -12.5PbF ₂ -3.5LaF ₃ −
2YF ₃ -2AlF ₃ -0.5InF ₃ -7LiF, 4
7.5ZrF ₄ -23.5BaF ₂ -2.5LaF ₃ -2
YF ₃ -4.5 AlF ₃ -20NaF (mol%), Δn is 3.7%, cutoff wavelength is 0.99 μm, loss is 49 dB / km (wavelength 1.4 μm), outer diameter is 125
μm and length 20 m. The excitation light source has a wavelength of 1.04.
Using a 7 μm Nd: YLF laser, 500 mW was incident from the front, the wavelength was 1.471 μm, and the light intensity was −20 dBm.
Was amplified. FIG. 2 (2) shows the change over time in the gain of an optical fiber module for optical amplification using a fluoride fiber in which Ce is not added to the core. The gain decreased with time, and deteriorated by 4 dB after 20 hours. FIG.
The optical loss spectra of the optical fiber module before (1) and after 2 hours (2) before the excitation light is incident. The loss increased with the incidence of the excitation light, and the amount of increase increased as the wavelength became shorter, and deteriorated by 10 dB or more at a wavelength of 1.1 μm or less.

(Embodiment 2) In the same configuration of the amplification optical fiber module as in Embodiment 1, Ce is added to the core in an amount of 0.5 to 0.5.
Using the amplification optical fiber doped with 10 wt%, the optical loss of the optical fiber module was measured under the same excitation conditions as in Example 1 before and after the excitation light was injected. Amplification optical fiber core with fluoride fiber doped with Tm of 2000ppm in the core, each clad mother phase 57ZrF ₄ -
16BaF ₂ -12.5PbF ₂ -3.5LaF ₃ -2Y
_{F 3 -2AlF 3 -7LiF, 47.5ZrF 4} -23.
5BaF ₂ -2.5LaF ₃ -2YF ₃ -4.5AlF _3-
20NaF (mol%), Δn is 3.7%, cutoff wavelength is 0.99 μm, and loss is 50 to 60 dB / km.
(Wavelength: 1.4 μm), the outer diameter was 125 μm, and the length was 20 m. The results are shown in Table 1.

[0031]

[Table 1]

FIG. 5 shows the relationship between the increase in loss of the optical fiber module at a wavelength of 1.1 μm and the amount of Ce added.
It can be seen that the loss hardly changes in the fiber module doped with 0.5 wt% to 10 wt% of Ce.
The value of the Ce concentration of 0 wt% in the figure is the data of Comparative Example 1, and is shown for comparison.

(Embodiment 3) In the same optical fiber module configuration for amplification as in Embodiment 1, 6000 ppm was added to the core.
Tm and 2 wt% of Ce were added.
Table 9 shows the results of measuring the optical loss of the optical fiber module before and after the excitation light was applied under the same excitation conditions as in Example 1 using 10 m of the amplification optical fiber made of the core and cladding matrix glass of Example 9. 3 is shown. No loss increase was observed.

[0034]

[Table 2]

[0035]

[Table 3]

Comparative Example 2 In the same optical fiber module configuration for amplification as in Example 1, 6000 ppm was added to the core.
Under the same pumping conditions as in Example 1, using the amplifying optical fiber 10m made of the core and cladding matrix glass of Tables # 1 to # 9 to which Tm was added, and before and after two hours from the excitation light injection Table 4 shows the measurement results of the optical loss of the optical fiber module of (1). After the excitation light was incident, a loss increase of 10 dB or more occurred at a wavelength of 1.1 μm.

[0037]

[Table 4]

(Embodiment 4) In the same configuration of the amplification optical fiber module as in Embodiment 1, a fluoride fiber in which 500 ppm of Pr and 3 wt% of Ce are added to the core is used as the amplification optical fiber, and excitation light is injected. The optical loss of the optical fiber module before and after 2 hours was examined. Pr on the core
The core of the fluoride fiber doped with Ce and, respectively cladding matrix, 22InF ₃ -16GaF ₃ -14ZnF
₂ -19PbF ₂ -13BaF ₂ -6SrF _2-3 YF _3-
3LaF ₃ -4LiF, 25.5InF ₃ -11.5Ga
F ₃ -14ZnF ₂ -2.5PbF ₂ -19BaF ₂ -8S
rF ₂ -2.5YF ₃ -2.5LaF ₃ -7.5NaF-
7LiF (mol%), Δn is 3.7%, cutoff wavelength is 1.0 μm, loss is 60 dB / km (wavelength 1.
2 μm), the outer diameter was 125 μm, and the length was 15 m. A Yb-doped quartz fiber laser with a wavelength of 1.03 μm was used as an excitation light source, and 1 W was incident from the front, and a wavelength of 1.31 μm.
m, the signal light having a light intensity of 0 dBm was amplified. As a result, no decrease in the gain was observed even after 20 hours, and the loss of the optical fiber module did not change.

(Comparative Example 3) In the same optical fiber module configuration for amplification as in Example 1, a fluoride fiber with 500 ppm Pr added to the core was used as the amplification optical fiber, and before and after 2 hours of the excitation light incidence. The optical loss of the optical fiber module was examined. The core and cladding matrix of the fluoride fiber doped with Pr are 22 InF ₃ −1
6GaF ₃ -14ZnF ₂ -19PbF ₂ -13BaF ₂ −
_{6SrF 2 -3YF 3 -3LaF 3 -4LiF,} 25.5
InF ₃ -11.5GaF ₃ -14ZnF ₂ -2.5Pb
F ₂ -19BaF ₂ -8SrF ₂ -2.5YF ₃ -2.5L
aF ₃ -7.5NaF-7LiF (mol%),
Δn is 3.7%, cutoff wavelength is 1.0 μm, and loss is 5
5 dB / km (wavelength 1.2 μm), outer diameter 125 μm,
The length was 15 m. A Yb-doped quartz fiber laser having a wavelength of 1.03 μm was used as an excitation light source, and 1 W was incident from the front to amplify signal light having a wavelength of 1.31 μm and a light intensity of 0 dBm. (1) of FIG. 6 is before the excitation light is incident, and (2) is 2
FIG. 6 is an optical loss spectrum of the optical fiber module after a time, in which the loss increases in a short wavelength region and deteriorates by 2 dB or more at a wavelength of 0.9 μm or less.

Example 5 In the same optical fiber module configuration for amplification as in Example 1, 500 ppm of Pr and 2 wt% of Ce were added to the core.
20m optical fiber consisting of core and cladding matrix
Table 6 shows the results of measuring the optical loss of the optical fiber module before and after 2 hours from the input of the excitation light under the same excitation conditions as those in Example 4. No loss increase was observed.

[0041]

[Table 5]

[0042]

[Table 6]

Comparative Example 4 In the same optical fiber module configuration for amplification as in Example 1, amplification light composed of the cores and cladding matrixes of # 1 to # 9 of Table 5 with 500 ppm of Pr added to the core. Table 7 shows the results of measuring the optical loss of the optical fiber module before and after the injection of the excitation light under the same excitation conditions as in Example 4 using the fiber 20m. After the excitation light was incident, the loss increased by 2 dB or more at a wavelength of 0.9 μm.

[0044]

[Table 7]

(Embodiment 6) In the same construction of the amplification optical fiber module as that of the embodiment 1, as the amplification optical fiber, a tellurite fiber in which 1000 ppm of Er and 2 wt% of Ce were added to the core was used, and pumping light was injected. The optical loss of the optical fiber module before and after 2 hours was examined. The core and cladding matrix of tellurite fiber having Er and Ce added to the core are 68.6 TeO ₂ -4.8 Bi ₂ O _3, respectively.
_{-19ZnO-7.6Na 2 O, 71TeO 2} -21Zn
O-8Na ₂ O (mol%), Δn was 2%, cutoff wavelength was 0.99 μm, loss was 60 dB / km (wavelength 1.3 μm), outer diameter was 125 μm, and length was 20 m. As the excitation light source, a stimulated Raman laser having a wavelength of 1.48 μm was used.
m, a signal light having a light intensity of 3.8 dBm was amplified. As a result, no decrease in the gain was observed even after 20 hours, and the loss of the optical fiber module did not change.

(Comparative Example 5) In the same optical fiber module configuration for amplification as in Example 1, a tellurite fiber in which 1000 ppm of Er was added to the core was used as an amplification optical fiber. The optical loss of the optical fiber module was examined. The core and cladding matrix of the fluoride fiber having Er added to the core are 68.
6TeO ₂ -4.8 Bi ₂ O ₃ -19ZnO-7.6Na ₂
O, 71TeO ₂ -21ZnO-8Na ₂ O (mol%)
Where Δn is 2%, cut-off wavelength is 1.0 μm, loss is 55 dB / km (wavelength 1.3 μm), and outer diameter is 125 μm.
m and length 20 m. 1.48μ wavelength for excitation light source
Using a guided Raman laser of m, 500 mW was incident from the front, and signal light having a wavelength of 1.56 μm and a light intensity of 3.8 dBm was amplified. (1) of FIG. 7 is before the excitation light is incident, (2)
Is the optical loss spectrum of the optical fiber module after 2 hours, the loss increased in the short wavelength region, and deteriorated by 3 dB or more at a wavelength of 0.9 μm or less.

(Embodiment 7) In the same configuration of the amplification optical fiber module as in Embodiment 1, 1000 ppm was added to the core.
No. 1 and # 2 in Table 8 to which Er and 2 wt% of Ce were added.
9 amplifying optical fiber 20 comprising core and cladding matrix
Table 9 shows the results of measuring the optical loss of the optical fiber module before and after the excitation light was applied under the same excitation conditions as in Example 6 using m. No loss increase was observed.

[0048]

[Table 8]

[0049]

[Table 9]

Comparative Example 6 In the same optical fiber module configuration for amplification as in Example 1, 1000 ppm was added to the core.
Using the amplification optical fiber 20m composed of the core and cladding matrix of Tables # 1 to # 9 in Table 8, to which Er was added, under the same pumping conditions as in Example 6, before and 2 hours after the pumping light was incident. Table 10 shows the results of measuring the optical loss of the optical fiber module. At a wavelength of 0.9 μm, a loss increase of 3 dB or more occurred.

[0051]

[Table 10]

[0052]

As shown in the above embodiments, according to the present invention, in an optical fiber module having a connection portion using a UV curable resin, an increase in loss and a decrease in gain due to high power excitation can be prevented. This improves the reliability of the optical fiber amplifier. Therefore, there is an advantage that the reliability and economy of the optical communication system can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of an optical fiber module for optical amplification used in the present invention.

FIG. 2 is a diagram showing a change with time of the gain of the optical fiber module for optical amplification in Example 1 and Comparative Example 1, which are indicated by (1) and (2), respectively.

FIG. 3 is a diagram showing an optical loss spectrum of an optical fiber module for optical amplification in Example 1 before (1) and after 2 hours (2) of excitation light incidence.

FIG. 4 is a diagram showing an optical loss spectrum of an optical fiber module for optical amplification in Comparative Example 1 before (1) excitation light incidence and after 2 hours (2).

FIG. 5 is a graph showing a relationship between an increase in loss of a module and a Ce addition amount at a wavelength of 1.1 μm in Example 2.

FIG. 6 is a diagram showing an optical loss spectrum before (1) and after 2 hours (2) of the excitation light of the optical fiber module for optical amplification in Comparative Example 3;

FIG. 7 is a diagram showing an optical loss spectrum of an optical fiber module for optical amplification in Comparative Example 5 before (1) excitation light incidence and after 2 hours (2).

[Explanation of symbols]

 a amplifying optical fiber b quartz optical fiber 1 c quartz optical fiber 2 d V-groove connection e core expanded fusion splice

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) H01S 3/06 G02B 6/24 301 (72) Inventor Kira Oikawa 2-3-1 Otemachi, Chiyoda-ku, Tokyo Issue Nippon Telegraph and Telephone Corporation (72) Inventor Tadashi Sakamoto 2-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Makoto Shimizu 2-chome Otemachi, Chiyoda-ku, Tokyo No. 1 Nippon Telegraph and Telephone Corporation (72) Inventor Yasutake Oishi 1-12-1 Dogenzaka, Shibuya-ku, Tokyo NTT Electronics Corporation F-term (reference) 2H036 JA00 MA03 2H050 AB33Z AB38Z AC03 AC81 AD00 4G062 AA06 BB11 BB17 BB18 CC10 DA01 DB01 DB02 DB03 DB04 DB05 DC01 DD01 DE01 DE02 DE03 DE04 DE05 DF01 DF02 DF03 DF04 DF05 EA01 EA02 EA03 EA04 EA05 EB01 E B02 EB03 EB04 EB05 EC01 EC02 EC03 EC04 EC05 ED01 EE04 EE05 EF01 EF02 EF03 EF04 EF05 EG01 EG02 EG03 EG04 EG05 FA01 FA02 FA03 FB01 FC01 FC02 FC03 FC04 FC05 FC06 FD01 FE01 F02 F03 F01 F02 F03 F01 F02 F03 F01 F02 F03 F01 F02 F03 F01 F02 F03 F01 F04 F03 F01 F02 F03 GA02 GA03 GA04 GB02 GC01 GD06 GD07 GE02 HH01 HH02 HH03 HH05 HH06 HH07 HH09 HH11 HH13 HH15 HH17 HH18 HH20 JJ01 JJ03 JJ05 JJ06 JJ07 JJ08 JJ10 KK01 KK02 KK03 KK17 KK10 KK0 KK05 KK05 KK05 KK05 KK05 KK05 KK10

Claims (7)

[Claims] 1. An amplifying optical fiber having a core and a cladding, wherein a core glass contains luminescent ions, and a silica optical fiber connected to both ends thereof, and a connection between the amplifying optical fiber and the silica optical fiber. 1. An optical fiber module for optical amplification having an end surface adhered using a UV curable resin, wherein the optical fiber for amplification is made of core glass to which Ce is added. 2. The optical fiber module for optical amplification according to claim 1, wherein the glass matrix of the optical fiber for amplification to which Ce is added is made of fluoride glass. 3. A method according to claim 2, wherein a part of the fluorine in the fluoride glass constituting the amplification optical fiber is replaced by at least one selected from the group consisting of chlorine, bromine and iodine. The optical fiber module for optical amplification according to the above. 4. The optical fiber module for optical amplification according to claim 1, wherein the glass matrix of the optical fiber for amplification to which Ce is added is made of sulfide glass. 5. The sulfide glass constituting the amplification optical fiber, wherein a part of sulfur is replaced by at least one selected from the group consisting of oxygen, chlorine, bromine and iodine. Item 5. An optical fiber module for optical amplification according to item 4. 6. The optical fiber module for optical amplification according to claim 1, wherein the glass matrix of the optical fiber for amplification to which Ce is added is made of tellurite glass. 7. The method according to claim 7, wherein the luminescent ions are Pr, Tm, Er, D
The optical fiber module for optical amplification according to claim 1, wherein the optical fiber module is at least one selected from the group consisting of y, Yb, Nd, and Ho.