JP2001024263A - EXCITATION METHOD FOR OPTICAL AMPLIFIER OR LASER OSCILLATOR OF 1.4-1.52 muM BAND - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve high efficiency by employing an excitation light source for exciting with wavelengths of a plurality of different kinds selected from respective specified ranges. SOLUTION: Tm ions contained in the core of an optical waveguide are excited to a basic state (3H6)3F2 or 3F3 with an exciting light of at least one wavelength selected from a wavelength range of 0.65-0.75 μm. It is relaxed to 3H4 through non-radiation relaxing process and light is emitted or amplified in 1.4-1.52 μm band through transition of 3H4→3F4. Subsequently, excitation takes place from under emission level (3H4)→3F2 or 3F3 with an excitation light of at least one wavelength selected from a wavelength range of 1.0-1.2 μm. Possibility of existence of 3F4 is effectively reduced through the exciting and self-stop mechanism can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to the field of 1.4 to 1.52.
The present invention relates to a method for exciting an optical amplifier or a laser oscillator used in optical communication in the μm band.

[0002]

2. Description of the Related Art In optical communication, a 1.55 .mu.m band which is the lowest loss wavelength of a quartz fiber, and 1.3 which is a zero dispersion wavelength.
The μm band has been used. Research and development of optical amplifiers have been actively conducted for these wavelength bands, and particularly, the 1.55 μm band has been very successful. In recent years, high-speed and large-capacity Internet and data transmission have been demanded, and wavelength multiplexing communication (WDM) has been put into practical use from the viewpoint of increasing communication capacity. However, with the 1.55 μm band alone, there is a possibility that the capacity will eventually become insufficient, and there has been a movement to seek another band. In particular, there is a strong demand to use the entire wide transmission wavelength range of quartz fibers from 1.3 to 1.7 μm for communication. For this reason, 1.47 μm band or 1.
Studies on 65 μm band fiber amplifiers have been actively conducted.

[0003]

It has been proposed to use a low phonon glass fiber doped with Tm for amplification or laser oscillation in the 1.47 μm band (1988).
Minutes of the 14th European Optical Commission Conference, DNPayne et al. Rareear
th-doping fiber laser and amplifiers pp49-53. and IEEE.J.Quantum Electronics vol.24 (6) (1988) 92
0-923). FIG. 1 shows the level of Tm. 1.47
The amplification in the μm band is performed by using the stimulated release process of ³ H ₄ → ³ F ₄ , and is actually 1.4 to 1.52 μm.
Has a wide gain and amplification band. As an excitation method, a two-step excitation at 1.06 μm (Japanese Patent Laid-Open No. 5-2 / 1993)
75792), and Tm of 0.7 to 0.89 μm band.
A method of directly exciting ³ H ₄ (JP-A-4-265251) and a method of two-step excitation in the 1.2 μm band (JP-A-4-265251)
No. 180279). But,
It is known that the fluorescence lifetime of the ³ H ₄ level of Tm is shorter than the fluorescence lifetime of ³ F ₄ , and it is difficult to obtain a population inversion necessary for amplification or laser oscillation. Such a characteristic is called a self-terminating mechanism, and is not suitable for highly efficient amplification or laser oscillation. Therefore, in order to short-life of the _{^{3 F 4, Eu, Tb,}} H
o, Pr, etc. (Japanese Unexamined Patent Publication No. 4-265251)
JP, JP-A-5-145168, JP-A-7-4
No. 5899). However, when these co-addition elements are added at a certain concentration or more, an undesired energy transfer occurs due to the absorption tail also in the 1.4 to 1.52 μm band of the target wavelength.
Since it adversely affects amplification efficiency in the 1.52 μm band,
There are restrictions on the composition of the amplification medium. Although proposals have been made to excite the Tm-doped fiber at two wavelengths, all of them are short-wavelength light sources utilizing an up-conversion process (for example, JP-A-5-319858 and JP-A-8-1983).
No. 307000).

Further, the ratio of the branching probability from ³ H _4, which is the upper level of light emission in the 1.47 μm band, to each level of ³ H ₅ , ³ F ₄ , and ³ H ₆ is 20: 50: 480 in order. Yes, overwhelmingly transition to the ground level. Therefore, ^3, a method for exciting the H ₄ directly (excitation wavelength 0.8μm so), by the excitation light of high intensity, ³ H ₄ than the stimulated emission of 1.47μm band ⁽³ H ₄ → ³ F ₄₎ → Stimulated release of ³ H ₆ is more than 10 times more likely to occur.
It has been virtually impossible to realize a 1.47 μm band amplifier or laser operating at a power conversion efficiency of 10% or more with an m-containing glass waveguide or fiber.

[0005]

The present inventors have conducted intensive studies in order to solve the above-mentioned problems. As a result, the present inventors have found that not only can an inversion distribution be efficiently formed between ³ H ₄ and ³ F ₄ , but also ³ H ₄ → ³ H ₆
The present inventors have found an excitation method capable of suppressing the emission of light, and have reached the present invention.

That is, the present invention provides a 1.4 to 1.52 μm band optical amplifier or laser oscillation device using an optical waveguide containing Tm in a core as an amplification medium, and at least a 1.0 to 1.2 μm excitation light source. A high efficiency 1.4 to 1.52 μm band optical amplifier or laser by pumping at two or more different wavelengths, at least one wavelength from the range and at least one wavelength from the 0.65 to 0.75 μm range. An oscillator is provided.

Hereinafter, the present invention will be described in detail.

A highly efficient 1.4 to 1.52 to which Tm is added
μm band (energy difference: about 6800cm ^-1) to the optical amplification or laser oscillation, the phonon energy 700 cm ^-1
The following low phonon energy materials are suitable, and high phonon energy materials (generally about 1000 cm ^-1 ) such as silica-based oxides and boric acid-based oxides are considered unsuitable. Such low phonon energy glass materials include halide glass, chalcogenide glass, halide oxide glass, chalcogenide glass, tellurite glass (tellurite glass), bismuthate glass,
Germanate glass, gallate glass and the like are known. However, these low phonon energy glass materials are also well known as up-conversion laser materials, and the excitation energy is consumed to emit red or blue light by a normal excitation method, and light emission in the 1.4 to 1.52 μm band is emitted. The efficiency is known to be very low. Also ³
The fluorescence lifetime of H ₄ is shorter than the fluorescence lifetime of ³ F ₄ , which is the lower level of light emission, and is a typical example of a self-stopping mechanism. It is known that laser oscillation itself is difficult. Very low efficiency (eg JYAllain et al., Electro
nics lett. 25 (1989) 1660-1662). Therefore, Eu, T
b, Ho, etc. were added Pr, attempts have been made to shorten the life of the fluorescence lifetime of the ³ F _4. However, since these co-addition elements also have a wide absorption wavelength band, if a concentration sufficient for shortening the life is added, absorption occurs in the 1.4 to 1.52 μm band, or an up-conversion process due to energy transfer occurs. There were problems such as a decrease in luminous efficiency in the 1.4 to 1.52 μm band. Further, as another method, since ³ F ₄ → ³ but H ₆ ³ F short life of ₄ using oscillation (basal) is considered, would discard nearly half of the energy of the excitation light, It is not preferable for efficiency. Still a major problem, the transition probability from the emission upper level of the Tm ⁽³ H ₄₎ to the ground level ⁽³ H ₆₎ is, like the point about 10 times the probability of transition to the ³ F ₄ object larger Can be For this reason, ³
In the H ₆ → ³ H ₄ excitation method (wavelength 0.8 μm band), stimulated emission ( ³ H ₄ → ³ H ₆ ) by high-intensity excitation light occurs simultaneously with the excitation process by absorption, and the ground state Tm ion There was a problem that the number could not be reduced and the efficiency was limited.

In contrast to these methods, the present invention has a wavelength of 0.6.
Excitation at two or more different wavelengths, at least one wavelength from the range of 5 to 0.75 μm and at least one wavelength from the range of 1.0 to 1.2 μm, enables inversion even without the co-addition element. Distribution is easy to form, and ³
H ₄ → ³ emission hardly occurs in H _6, in which found that is amplifiable or laser oscillation with high efficiency at low excitation power.

The excitation method of the present invention will be described in more detail with reference to FIG.
A description will be given below. First, it is contained in the core of the optical waveguide.
Tm ions selected from wavelengths of 0.65 to 0.75 μm
At least one wavelength of excitation light (hereinafter referred to as excitation light 1).
Depending on the ground state (^ThreeH₆) →^ThreeF_TwoOr^ThreeF_ThreeEncourage
(Excitation process 1). Next, the radiationless relaxation process (radiation
After about 1)^ThreeH_FourRelaxed^ThreeH_Four→^ThreeF_FourTransition (radiation
In step 2), light emission or amplification in the 1.4 to 1.52 μm band
Occurs. Next, the wavelength is selected from the range of 1.0 to 1.2 μm.
Pump light of at least one wavelength (hereinafter referred to as pump light 2).
The lower emission level (^ThreeF_Four) →^ThreeF_TwoOr^ThreeF_ThreeTo
Excite (excitation process 2). With this excitation ^ThreeF_FourThe presence of
The probability can be effectively reduced and the self-stopping mechanism can be avoided.
Finally,^ThreeF_TwoOr^ThreeF_Three→^ThreeH_FourNon-radiative transition (radiative process
After 1), again^ThreeH_Four→^ThreeF_Four(Emission process 2)
Light emission in the 4-1.52 μm band occurs. With this excitation method
Is immediately apparent from FIG.^ThreeF_FourIs the virtual ground level
Is a four-level process used to form a population inversion
Is very easy. Also, with this method,^ThreeH_Four→^Three
H₆0.8μm band of strong light corresponding to the energy difference of
Does not exist,^ThreeH_Four→^ThreeH₆Induced radiation is difficult to occur
And^ThreeH_Four→^ThreeF_FourCan be increased.

[0011] To describe the absorption spectrum based on the excitation method of the present invention in FIG. 3, the excitation light 1 ³ H ₆ → ³ F ₃
Or ³ H ₆ → ³ F ₂ transition, ³ F ₄ → ³ F ₂ by excitation light ₂
Or ³ F ₄ → ³ transition F ₃ that occurs can be easily understood. Also, among the excitation wavelengths 1, 0.68 to 0.72 μm
m band, ³ for H ₄ → ¹ D ₂ and ³ H ₅ → ¹ can be avoided G ₄ of the up-conversion process simultaneously, in particular preferred. Also,
Among the excitation wavelengths 2, the 1.0-1.1 μm band has ³ H ₄ →
Because it can avoid the up-conversion process of ¹ G _4, particularly preferred.

The optimal wavelength selection of the excitation wavelength 1 and the excitation wavelength 2 cannot be specified unconditionally because it varies depending on the added concentration of Tm and the type of glass material, but is set within the range of each wavelength band of the present invention. be able to. For example, Tm: ZBLA
In N (fluoride glass), 0.69 μ as the excitation wavelength 1
m and the excitation wavelength 2 can be 1.064 μm. The optimum combination of the excitation light power depends on the Tm concentration, the material of the optical waveguide, the numerical aperture of the waveguide, etc., and cannot be unconditionally specified. However, it is expressed by the power of the excitation wavelength 1: the power of the excitation wavelength 2. Excitation power ratio is 95: 5 to 5: 9
It is preferably in the range of 5. When the excitation wavelength 2 (wavelength 1.0 to 1.2 μm) is weaker than this range, ³ H ₄ and
^{It is} difficult to form a population inversion between ³ F ₄ , so that sufficient amplification efficiency cannot be obtained. Excitation wavelength 1 (wavelength 0.
(65-0.75 μm) is weak, the ground level ( ³ H ₆ )
→ Since the excitation of ³ F ₂ or ³ F ₃ is not performed effectively, the proportion of ions available for amplification decreases, and gain cannot be obtained. Further, the above-mentioned excitation power ratio is 80:20 to 20: 8.
In the range of 0, a population inversion can be formed even with a low excitation power, which is particularly preferable.

When the excitation method of the present invention is used, it is clear that any material capable of amplifying the 1.47 μm band in the Tm-added medium can be used. As such a material, a glass having a low phonon energy is generally used, and chalcogenide glass, halide glass, chalcogenide glass, halide oxide glass, tellurite glass (tellurite glass), bismuthate Glass, germanate glass, gallate glass and the like are preferable, and it is particularly preferable to use them for the core.

As the excitation laser, a semiconductor laser,
Any laser that oscillates in the excitation wavelength band of the present invention, such as a dye laser, a solid laser, and a gas laser, may be used.
Particularly preferred are a semiconductor laser with a fiber pigtail, a solid laser coupled with a fiber, and a fiber laser. In terms of price and size, a semiconductor laser is used for the excitation wavelength 1 (wavelength 0.65 to 0.75 μm), and a solid laser to which Nd or Yb is added for the excitation wavelength 2 (wavelength 1.0 to 1.2 μm). Fiber lasers are preferred. In addition, in order to enhance the pumping efficiency by making full use of the Tm absorption band, a laser having a wide oscillation wavelength band (for example, a Raman laser) is used, or a plurality of lasers having different wavelengths in each excitation wavelength band are combined. Is also effective.

When configuring an optical amplifier, optical communication optical elements such as a wavelength division multiplexing element (WDM) and an optical isolator can be used as needed. In addition, it is preferable that a gain monitoring function and a gain equalization function are built in or attached to the amplifier because the reliability of the optical communication system is improved.
For monitoring the gain, any method may be used as long as the method can substantially compare the incident signal light intensity and the output signal light intensity. In the case of performing wavelength division multiplexing communication, a method capable of detecting and monitoring each signal assigned to each wavelength is desirable. The gain equalization function may be a passive method or an active method. As a passive gain equalization method, a configuration using an optical filter is simple. The active gain equalization method comprises a gain monitoring function and a feedback function, substantially compares the incident signal light intensity and the output signal light intensity, and may use any method as long as the method can keep the gain constant. . When performing wavelength division multiplexing communication, it is desirable to use a method that can equalize the gain for each signal assigned to each wavelength. Although the function is the same as the gain equalization function, the output equalization function for keeping the output signal light intensity constant is also effective like the gain equalization function. Preferably, these functions are automatically adjustable by a remotely programmable microprocessor or the like.

When a laser oscillator is formed, a high output can be achieved by connecting the optical waveguides in a ring shape or by connecting a plurality of optical waveguides in series or in parallel. Also, narrow band oscillation and wavelength tunable oscillation using a fiber grating or the like, and ultrashort pulse oscillation by pulse compression are possible.

As described above, the excitation wavelength is set to the wavelength of 0.65 to 0.65.
By using two-wavelength excitation of 0.75 μm band and wavelength of 1.0 to 1.2 μm, 1.4 is more efficient than ordinary one-wavelength excitation.
It is possible to provide an optical amplifier or laser oscillator in the band of 1.52 μm.

[0018]

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

Example 1 A fluoride glass fiber containing 0.1 mol% of Tm added to a core was used. The basic glass compositions of the core and the clad are shown below. Tm replaces La. The numbers are
mol%.

Core composition: 51ZrF ₄ -19BaF _2-
4.5LaF ₃ -2YF ₃ -2AlF ₃ -13.5LiF
-8PbF ₂ cladding composition: 40HfF ₄ -10ZrF ₄ -19BaF
_2-3 LaF ₃ -2YF ₃ -4AlF ₃ -22NaF This fiber had a relative refractive index difference of 1.1%, a cutoff wavelength of 0.65 μm, and a core diameter of 2.2 μm.
The fiber length is 3 m.

Next, the configuration of the optical amplifier used for the measurement is shown in FIG.
Shown in For excitation, a semiconductor laser 2 having a wavelength of 0.69 μm and a Nd: YAG laser 3 having a wavelength of 1.064 μm are multiplexed, and a fluoride fiber for optical amplification is passed through an optical multiplexing / demultiplexing element 4 and a quartz fiber 5 having a high NA. It is connected to 1.
The quartz fiber 5 and the fluoride fiber 1 were bonded using a V-groove block, and the bonded end face was obliquely optically polished to reduce reflection loss, and fixed with an ultraviolet-curable optical adhesive. 1. The signal light from the signal generator 6 in the 1.47 μm band enters the amplifying fiber via the optical multiplexing / demultiplexing element 4, and the amplified outgoing light passes through the optical isolator 7 and is measured by the measuring device 8.
The measurement of the small signal gain was performed. The input signal light is continuous light having a wavelength of 1.47 μm and an intensity of −30 dBm. FIG. 5 shows the small signal gain when pumping at a single wavelength of 0.69 μm or 1.064 μm and the small signal gain when pumping at two wavelengths simultaneously. The input power in the case of two-wavelength excitation is the total power of the two wavelengths, and the power ratio is fixed at 4: 6. It can be seen that in the two-wavelength pump, the gain is improved by 5 dB or more with respect to the single-wavelength pump, and the threshold value is low.

Example 2 An experiment was performed using the same fluoride fiber as in Example 1 and changing the excitation power ratio with the same configuration. The incident conditions and the excitation wavelength of the signal light were the same as in Example 1, and the measurement was performed with the total power of the two wavelengths fixed at 100 mW. FIG. 6 shows the results. When the power ratio between the excitation wavelength of 0.69 μm and 1.064 μm is in the range of 95: 5 to 5:95, the wavelength is 0.69 μm.
Alternatively, it can be seen that the gain is higher than in the case of single wavelength excitation at a wavelength of 1.064 μm. In particular, the power ratio is 80: 2
In the range of 0 to 20:80, the gain was at least 2 dB higher than the gain in the case of single wavelength pumping.

Example 3 A small signal gain was measured in the same configuration as in Example 1 except that the amplification medium was an In-based fluoride glass fiber. The addition concentration of Tm is 0.2 mol%, and a part of Gd is substituted. The numbers are mol%.

Core composition: 18InF ₃ -12GaF ₃ -2
_{0ZnF 2 -27BaF 2 -3PbF 2 -10GdF 3} -1
0YF ₃ clad composition: 18InF ₃ -12GaF ₃ -20ZnF
₂ -18BaF ₂ -12SrF ₂ -10GdF ₃ -10YF
₃ The relative refractive index difference of this fiber was 1.1%, and the cutoff wavelength was 0.65 μm. The fiber length used for the measurement is 2 m. For excitation, a semiconductor laser having a wavelength of 0.695 μm and a Yb: YAG laser having a wavelength of 1.02 μm were used. As a result of measuring single-wavelength excitation and dual-wavelength excitation (power ratio 4: 6) in the same manner as in Example 1, as shown in FIG. 7, the dual-wavelength excitation had a higher gain by 5 dB or more.

Example 4 A small signal gain was measured with the same configuration as in Example 1 and a tellurite-based oxide glass fiber as the amplification medium. Tm
Is 0.1 mol%, and partially replaces La. The numbers are mol%.

Core composition: 90 TeO ₂ -8BaO-2L
a ₂ O ₃ cladding _{composition: 81TeO 2 - 16BaO -3Y 2 O} 3 relative refractive index difference of the fiber, 0.7%, cut-off wavelength was 0.65 .mu.m. The fiber length used for the measurement is 1.5 m. For excitation, a semiconductor laser having a wavelength of 0.695 μm and a Nd: YVO ₄ laser having a wavelength of 1.064 μm were used. As shown in FIG. 8, the gain was higher by 3 dB or more in the two-wavelength excitation than in the single-wavelength excitation.

Example 5 A small signal gain was measured using the same configuration as in Example 1 except that the amplification medium was a bismuth-based oxide glass fiber. The addition concentration of Tm is 0.1 mol%, and a part of La is substituted. The numbers are mol%.

Core composition: 75 Bi ₂ O ₃ -18 B ₂ O ₃ -5
SiO ₂ -2La ₂ O ₃ clad composition: 70 Bi ₂ O ₃ -15CdO-15B ₂ O ₃ Fiber had a relative refractive index difference of 1.2% and a cutoff wavelength of 0.65 μm. The fiber length used for the measurement is 2 m. For excitation, a semiconductor laser having a wavelength of 0.695 μm and a Nd: YLF laser having a wavelength of 1.057 μm were used. As a result of measuring single-wavelength excitation and dual-wavelength excitation (power ratio: 1: 1) as in Example 1, as shown in FIG. 9, the dual-wavelength excitation has a higher gain by 3 dB or more.

Example 6 A small signal gain was measured in the same configuration as in Example 1 except that the amplification medium was a gallate glass fiber. The addition concentration of Tm is 0.3 mol%. The numbers are mol%.

Core composition: 30K ₂ O-30Ta ₂ O ₃ -4
0Ga ₂ O ₃ cladding _{composition: 30K 2 O-25Ta 2 O} 3 -45Ga 2 O
₃ The relative refractive index difference of this fiber was 1.2%, and the cutoff wavelength was 0.65 μm. The fiber length used for the measurement is 0.7 m. Excitation is performed by using a semiconductor laser having a wavelength of 0.695 μm and Nd: YAG having a wavelength of 1.064 μm.
A laser was used. As a result of measuring single-wavelength excitation and dual-wavelength excitation (power ratio 1: 1) as in Example 1,
As shown in FIG. 10, the two-wavelength pump had a higher gain by 3 dB or more.

Example 7 A small signal gain was measured in the same configuration as in Example 1 except that the amplification medium was a sulfide glass fiber. The addition concentration of Tm is 0.1 mol%. Tm replaces La. The numbers are mol%.

Core composition: 30 In_TwoS_Three-40Ga_TwoS_Three−
30La_TwoS_Three Cladding composition: 12Al (PO_Three)_Three-11AlF_Three-3
0.5RF_Two -46.5MF_Two (R: Mg, Ca M: S
r, Ba) The relative refractive index difference of this waveguide is 1.2%, the cutoff wavelength
Was 0.65 μm. Fiber used for measurement
Is 1.5 m in length. Single wavelength excitation as in the first embodiment
And the result of measurement of two-wavelength excitation (power ratio 1: 1)
As a result, as shown in FIG.
High gain.

[0033]

By using the excitation method of the present invention,
Highly efficient 1.4 to 1.52 μm band optical amplifier or 1.4
A laser oscillator of 1.52 μm band can be constructed.

[Brief description of the drawings]

FIG. 1 is a level diagram and an absorption spectrum of Tm.

FIG. 2 is a diagram illustrating the level of Tm and the excitation method of the present invention.

FIG. 3 is a diagram showing an absorption cross section from each level of Tm.

FIG. 4 is a configuration diagram of an amplifier according to the first embodiment.

FIG. 5 is a diagram showing pump power dependence of the amplification factor in the first embodiment.

FIG. 6 is a diagram showing the power ratio dependence of the amplification factor of the excitation wavelength 1 and the excitation wavelength 2 in Example 2.

FIG. 7 is a diagram illustrating the dependence of the amplification factor on the excitation power in the third embodiment.

FIG. 8 is a diagram illustrating pump power dependence of the amplification factor in the fourth embodiment.

FIG. 9 is a diagram showing pump power dependence of the amplification factor in Example 5.

FIG. 10 is a diagram showing pump power dependence of the amplification factor in Example 6.

FIG. 11 is a diagram showing pump power dependence of the amplification factor in Example 7.

[Explanation of symbols]

 Reference Signs List 1 optical amplification fiber 2 semiconductor laser supplying excitation wavelength 1 3 Nd: YAG laser supplying excitation wavelength 2 4 optical multiplexing / demultiplexing element 5 high NA quartz fiber 6 signal light generator with wavelength of 1.47 μm 7 optical isolator 8 measurement vessel

Continuing from the front page (72) Inventor Kiyotaka Miura 5253 Oki Obe, Oji, Ube City, Yamaguchi Prefecture Inside the Chemical Research Laboratory of Central Glass Co., Ltd. (72) Inventor Takuya Teshima 5253 Oki Ube Oaza, Ube City, Yamaguchi Prefecture, Japan F-term in the laboratory (reference) 4G062 AA06 BB07 BB10 BB11 BB16 BB18 LA10 MM04 NN01 NN40 5F072 AB07 AK06 PP07 RR01 YY17

Claims (7)

[Claims] 1. A 1.4 to 1.52 μm band optical amplifier including at least a pumping light source, a multiplexer / demultiplexer, and an amplification optical waveguide, wherein the core of the amplification optical waveguide contains Tm and has a wavelength of 1. Excitation is performed at two or more different wavelengths, that is, at least one wavelength from the range of 0 to 1.2 μm and at least one wavelength from the range of 0.65 to 0.75 μm. Excitation method for 52 μm band optical amplifier. 2. A 1.4 to 1.52 μm band laser oscillator having at least a pump light source, a multiplexer / demultiplexer, and an amplification optical waveguide, at least one wavelength from a wavelength range of 1.0 to 1.2 μm and a wavelength of A pumping method for a 1.4 to 1.52 μm-band laser oscillator, characterized in that pumping is performed at two or more different wavelengths of at least one wavelength from a range of 0.65 to 0.75 μm. 3. The core of the amplification optical waveguide is made of halide oxide glass, halide glass, chalcogenide glass,
3. The glass according to claim 1, wherein the glass comprises at least one kind of glass selected from the group consisting of chalcogenide glass, tellurite glass, bismuthate glass, germanate glass, and gallate glass. 1.
A method for exciting a 52 μm band optical amplifier or laser oscillator. 4. The pumping method for a 1.4 to 1.52 μm band optical amplifier or a laser oscillator according to claim 1, wherein at least one of the pumping light sources is a semiconductor laser. 5. The method according to claim 1, wherein at least one of the pumping light sources is a solid-state laser pumped by a semiconductor laser.
The method for exciting a 1.4 to 1.52 μm band optical amplifier or laser oscillator according to any one of claims 1 to 3. 6. The 1.4 to 1.52 μm band according to claim 5, wherein the solid-state laser is a laser using a crystal doped with Nd or Yb or a glass fiber doped with Nd or Yb. A method for exciting an optical amplifier or a laser oscillator. 7. An excitation power of an excitation wavelength selected from a wavelength range of 0.65 to 0.75 μm and a wavelength of 1.0 to 1.2.
The ratio of the excitation power of the excitation wavelength selected from the range of μm is
The ratio is in the range of 95: 5 to 5:95, and is in the range of 1.4 to 1.52 μ according to any one of claims 1 to 6.
Excitation method for m-band optical amplifier or laser oscillator.