In-band pumping optical fiber amplifier

Abstract

The utility model provides an in-band pumping optical fiber amplifier. The optical fiber amplifier comprises a first isolator, a first gain optical fiber and a second isolator which are sequentially arranged along the direction of an optical path, at least one first beam combiner is arranged between the first isolator and the second isolator and is connected with at least one pumping device in a beam combining mode, and the pumping device is an amplifier structure pumping device or an oscillator structure pumping device. According to the utility model, the design is reasonable, the 1535nm pumping wavelength selected by the optical fiber amplifier and the target L-band laser wavelength (1565nm-1625nm) are in the same energy band of erbium ions, the quantum loss between the 1535nm pumping wavelength and the target L-band laser wavelength is small, the pumping efficiency of the laser can be effectively improved, and the thermal load of the laser can be reduced, so that the light output power and efficiency of the laser are improved, and the noise characteristic of the laser is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a same belt pumping optical fiber amplifier. BACKGROUND

[0002] With the rapid development of information technology, people's requirements for communication capacity and transmission distance are continuously improved. As the main mode of modern communication, optical fiber communication needs to continuously optimize its transmission performance. In an optical communication system, optical signals will inevitably produce attenuation during transmission. In order to compensate for this attenuation, optical fiber amplifiers emerge as the times require. The early optical fiber amplifier is mainly erbium-doped fiber amplifier (EDFA), which has excellent performance in C-L band (1530nm~1625nm), can effectively amplify optical signals, and promotes the wide application of wavelength division multiplexing (WDM) technology. The L-band erbium-doped fiber amplifier (EDFA) usually uses a 980nm semiconductor laser as a pump source. Due to the high quantum loss in this conversion process and the serious heat effect, the pump light conversion efficiency is low, and the gain level is difficult to meet the demand of high gain, thereby limiting the output power and efficiency of the L-band erbium-doped fiber amplifier. SUMMARY

[0003] Therefore, the utility model discloses a same belt pumping optical fiber amplifier, which can effectively improve the pumping efficiency of the laser, reduce the thermal load of the laser, thereby improving the light output power, efficiency of the laser and improving its noise characteristics.

[0004] The utility model adopts the following scheme to realize: a same belt pumping optical fiber amplifier: the optical fiber amplifier includes first isolator, first gain optical fiber, second isolator arranged in turn along the light path direction, there is at least a first beam combiner and at least one pump device connected by the first isolator and the second isolator;

[0005] The first isolator transmits the signal light of L band in the positive direction and isolates the backward transmission light;

[0006] The pump device outputs forward or reverse pump coupling light;

[0007] The first beam combiner couples the input signal light and pump coupling light into the first gain optical fiber;

[0008] The first gain optical fiber absorbs pump coupling light and amplifies the signal light of L band;

[0009] The second isolator transmits the amplified signal light of L band in the positive direction and isolates the backward transmission light.

[0010] Further, the pumping device is an amplifier structure pumping device, which comprises a signal source, a third isolator, a second gain optical fiber and a fourth isolator arranged in sequence along the direction of optical path transmission.

[0011] Further, the first pumping source generates pump light of 940nm or 976nm; the signal source generates signal light of 1535nm; the third isolator allows the signal light of 1535nm to pass in one direction and isolates light transmitted in the opposite direction; the second combiner couples the signal light of 1535nm and the pump light of 940nm or 976nm; the second gain optical fiber absorbs the pump light of 940nm or 976nm and amplifies the signal light of 1535nm; and the fourth isolator is used for transmitting the amplified signal light of 1535nm and isolating light transmitted in the opposite direction.

[0012] Further, the pumping device is an oscillator structure pumping device, which comprises a second pumping source, a third gain optical fiber, a partially reflective fiber grating and a fifth isolator arranged in sequence along the direction of optical path transmission.

[0013] Further, the second pumping source generates pump light of 940nm or 976nm; the third combiner is used for coupling the pump light of 940nm or 976nm to the third gain optical fiber; the third gain optical fiber is used for absorbing the pump light of 940nm or 976nm to form population inversion; the high reflective fiber grating and the partially reflective fiber grating constitute a laser oscillation cavity, the partially reflective fiber grating outputs signal light of 1535nm; and the fifth isolator is used for transmitting the signal light of 1535nm in the forward direction and isolating light transmitted in the opposite direction.

[0014] Further, the pumping device is coupled between the first isolator and the first gain optical fiber through the first optical combiner to constitute forward pumping or between the first gain optical fiber and the second isolator to constitute reverse pumping.

[0015] Further, the pumping device is coupled between the first isolator and the first gain optical fiber through the first optical combiner to constitute forward pumping or between the first gain optical fiber and the second isolator to constitute reverse pumping.

[0016] Further, the first gain optical fiber is an erbium-doped single-clad or double-clad optical fiber.

[0017] Further, the second gain optical fiber is an erbium-doped or erbium-ytterbium co-doped single-clad or double-clad optical fiber.

[0018] Further, the third gain optical fiber is an erbium-doped or erbium-ytterbium co-doped single-clad or double-clad optical fiber.

[0019] Compared with the prior art, the utility model has the following beneficial effects: the 1535nm pump wavelength of the optical fiber amplifier is selected in the same energy band with the target L wave band laser wavelength (1565nm~1625nm), the quantum loss between the two is small, the pump efficiency of the laser can be effectively improved, the heat load of the laser is reduced, thereby the light output power, efficiency of the laser are improved and the noise characteristic thereof is improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is the structure schematic view of the utility model embodiment 1;

[0021] Figure 2 It is the structure schematic view of the utility model embodiment 2.

[0022] In the drawing: 1, first isolator;2, first beam combiner;3, first gain optical fiber;4, second isolator;5, amplifier structure pump device;501, first pump source;502, signal source;503, third isolator;504, second beam combiner;505, second gain optical fiber;506, fourth isolator;6, oscillator structure pump device;601, second pump source;602, high reflection fiber grating;603, third beam combiner;604, third gain optical fiber;605, partial reflection fiber grating;606, fifth isolator. DETAILED DESCRIPTION

[0023] The utility model will be further described below in connection with the drawings and examples.

[0024] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0025] It should be noted that the terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form, and in addition, it should be understood that when the terms "comprise" and / or "include" are used in the specification, they indicate the presence of a feature, step, operation, device, component and / or their combination.

[0026] Example 1, as Figure 1As shown, a kind of co-pumping fiber amplifier: the fiber amplifier includes by the first isolator 1, first gain optical fiber 3, second isolator 4 arranged in sequence along the light path direction;There is at least one first beam combiner 2 between the first isolator and the second isolator, and at least one pump device is connected, that is, there is at least one first beam combiner, and at least one pump device is connected to each first beam combiner;

[0027] The first isolator transmits the signal light of L band in the positive direction, and isolates the backward transmission light;

[0028] The pump device outputs forward or reverse pump coupling light;

[0029] The first beam combiner couples the input signal light and pump coupling light into the first gain optical fiber;

[0030] The first gain optical fiber absorbs pump coupling light, and amplifies the signal light of L band;

[0031] The second isolator transmits the amplified signal light of L band in the positive direction, and isolates the backward transmission light.

[0032] In the embodiment, the pump device is an amplifier structure pump device 5, and the amplifier structure pump device includes a signal source 502, a third isolator 503, a second gain optical fiber 505 and a fourth isolator 506 arranged in sequence along the light path transmission direction;The third isolator and the second gain optical fiber are connected to the first pump source 501 through a second beam combiner 504.

[0033] In the embodiment, the first pump source generates pump light of 940nm or 976nm;The signal source generates signal light of 1535nm;The third isolator passes the signal light of 1535nm in one direction and isolates the backward transmission light;The second beam combiner couples the signal light of 1535nm and the pump light of 940nm or 976nm;The second gain optical fiber absorbs the pump light of 940nm or 976nm, and amplifies the signal light of 1535nm;The fourth isolator is used for transmitting the amplified signal light of 1535nm, and isolating the backward transmission light.

[0034] In the embodiment, the number and installation position of the first light beam combiner can be set according to specific needs, specifically: the pump device is coupled between the first isolator and the first gain optical fiber through the first light beam combiner to form forward pumping or between the first gain optical fiber and the second isolator to form reverse pumping, and the pump device can also be arranged between the first isolator and the first gain optical fiber and between the first gain optical fiber and the second isolator and coupled through the first light beam combiner to form bidirectional pumping.

[0035] In this embodiment, the specific working principle is as follows: The first pump source emits 940nm or 976nm pump light, which is coupled into the second gain fiber through the second combiner. The signal source emits 1535nm laser light, which enters the second gain fiber after passing through the third isolator. The 940nm or 976nm pump light is absorbed by the second gain fiber, resulting in population inversion. The 1535nm laser light is amplified in the second gain fiber. The amplified 1535nm laser light is transmitted to the first combiner after passing through the fourth isolator and is coupled into the first gain fiber. The L-band signal light (1565nm~1625nm) is coupled into the first gain fiber after passing through the first isolator and the first combiner. The first gain fiber absorbs the 1535nm laser light, resulting in population inversion. The L-band signal light is amplified in the first gain fiber and finally outputs the amplified L-band signal light after passing through the second isolator.

[0036] In this embodiment, the first gain fiber is an erbium-doped single-clad or double-clad fiber.

[0037] In this embodiment, the second gain fiber is an erbium-doped or erbium-ytterbium co-doped single-clad or double-clad fiber.

[0038] Example 2, as Figure 2 As shown, compared with Embodiment 1, the pumping device adopts an oscillator structure. Since other structures are the same as in Embodiment 1, they will not be described in detail. Only the differences in structure will be explained. Specifically, the pumping device is an oscillator structure pumping device 6. The oscillator structure pumping device includes a second pump source 601, a third gain fiber 604, a partially anti-fiber grating 605, and a fifth isolator 606 arranged sequentially along the optical path transmission direction. The second pump source and the third gain fiber are bundled and connected by a third combiner 603 with a high-reflection fiber grating 602.

[0039] In this embodiment, the second pump source generates pump light at 940nm or 976nm; the third combiner couples the 940nm or 976nm pump light to the third gain fiber; the third gain fiber absorbs the 940nm or 976nm pump light to form population inversion; a high-reflectivity fiber grating and a partially anti-fiber grating form a laser oscillation cavity, and the partially anti-fiber grating outputs a 1535nm signal light; the fifth isolator transmits the 1535nm signal light in the forward direction and isolates the backward-transmitted light.

[0040] In this embodiment, the third gain fiber is an erbium-doped or erbium-ytterbium co-doped single-clad or double-clad fiber.

[0041] In the embodiment, the specific working principle is that the second pump source emits 940nm or 976nm pump light, enters into the third gain optical fiber through the third beam combiner, particle number inversion is generated, the high-reflection fiber grating fully reflects the 1535nm laser, the partial-reflection fiber grating partially reflects the 1535nm laser, the high-reflection fiber grating and the partial-reflection fiber grating form a laser resonant cavity, thereby forming 1535nm laser oscillation, after multiple reflections in the resonant cavity, the high-power 1535nm laser is output from the partial-reflection fiber grating, and the 1535nm laser is coupled into the first gain optical fiber through the first beam combiner after passing through the fifth isolator.

[0042] If the above-mentioned utility model discloses any technical scheme and declares that the numerical range is disclosed, then the disclosed numerical range is the preferred numerical range, and any person skilled in the art should understand that the preferred numerical range is only one of the many implementable values with more obvious technical effects or representative values. Since there are too many values, it is impossible to enumerate them, therefore, the utility model only discloses part of the values to illustrate the technical scheme of the utility model, and the above-mentioned enumerated values should not constitute a limitation on the protection scope of the utility model.

[0043] If the terms "first", "second", etc. are used to limit the components in the text, those skilled in the art should know that the use of "first", "second" is only for the convenience of distinguishing the components, and the above-mentioned terms have no special meaning unless otherwise stated.

[0044] If the utility model discloses or involves components or structural members that are fixedly connected to each other, unless otherwise stated, the fixed connection can be understood as detachable fixed connection (for example, connected by bolts or screws), and can also be understood as non-detachable fixed connection (for example, riveting, welding), of course, the mutually fixed connection can also be replaced by an integral structure (for example, integrally formed by using casting process) (except for obvious cases that cannot use integral forming process).

[0045] In addition, the position relationship indicated by the terms such as "vertical", "horizontal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like in any of the technical solutions of the utility model disclosed above is the position relationship shown in the drawings, which is only for the convenience of describing the patent and does not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the patent, and the terms used to indicate the shape in any of the technical solutions of the utility model disclosed above include shapes similar, similar or close to the shape unless otherwise stated.

[0046] Any component provided by the utility model can be assembled from a plurality of separate components, or can be a separate component manufactured by an integral forming process.

[0047] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the utility model and not to limit them; although the utility model has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the utility model can still be modified or some technical features can be replaced by equivalents; without departing from the spirit of the technical solutions of the utility model, they should all be included in the technical solutions of the utility model claimed in the utility model.

Claims

1. A single band pumped fiber amplifier, characterized by: The optical fiber amplifier comprises a first isolator, a first gain optical fiber and a second isolator arranged in sequence along an optical path direction; at least one first combiner is connected with at least one pump device between the first isolator and the second isolator; The first isolator transmits signal light of L band in a forward direction and isolates backward-transmitted light; The pump device outputs forward or backward pump-coupled light; The first combiner couples input signal light and pump-coupled light into the first gain optical fiber; The first gain optical fiber absorbs pump-coupled light and amplifies signal light of L band; The second isolator transmits amplified signal light of L band in a forward direction and isolates backward-transmitted light; The pump device is an amplifier structure pump device, which comprises a signal source, a third isolator, a second gain optical fiber, a fourth isolator arranged in sequence along an optical path transmission direction; the third isolator and the second gain optical fiber are connected with a first pump source through a second combiner.

2. The same band pumped fiber amplifier of claim 1, wherein: The first pump source generates pump light of 940 nm or 976 nm; the signal source generates signal light of 1535 nm; the third isolator passes signal light of 1535 nm in one direction and isolates backward-transmitted light; the second combiner couples signal light of 1535 nm and pump light of 940 nm or 976 nm; the second gain optical fiber absorbs pump light of 940 nm or 976 nm and amplifies signal light of 1535 nm; the fourth isolator is used for transmitting amplified signal light of 1535 nm and isolating backward-transmitted light.

3. A single stage single pump fiber optical amplifier as claimed in any one of the claims 1-2, characterized in that: The pump device is coupled between the first isolator and the first gain optical fiber through the first optical combiner to form forward pumping or between the first gain optical fiber and the second isolator to form backward pumping.

4. The same-polarization pumped fiber amplifier according to any of claims 1-2, characterized in that: The pump device is coupled between the first isolator and the first gain optical fiber through the first optical combiner to form forward pumping or between the first gain optical fiber and the second isolator to form backward pumping.

5. The same-polarization pumped fiber amplifier of any of claims 1-2, wherein: The first gain optical fiber is an erbium-doped single-clad or double-clad optical fiber; the second gain optical fiber is an erbium-doped or erbium-ytterbium co-doped single-clad or double-clad optical fiber.

6. A co-pumped fiber amplifier, characterized by: The optical fiber amplifier comprises a first isolator, a first gain optical fiber and a second isolator arranged in sequence along an optical path direction; at least one first combiner is connected with at least one pump device between the first isolator and the second isolator; The first isolator transmits signal light of L band in a forward direction and isolates backward-transmitted light; The pump device outputs forward or backward pump-coupled light; The first combiner couples input signal light and pump-coupled light into the first gain optical fiber; The first gain optical fiber absorbs pump-coupled light and amplifies signal light of L band; The second isolator transmits amplified signal light of L band in a forward direction and isolates backward-transmitted light; The pump device is an oscillator structure pump device, which comprises a second pump source, a third gain optical fiber, a partial reflective fiber grating and a fifth isolator arranged in sequence along an optical path transmission direction; a high-reflective fiber grating is connected between the second pump source and the third gain optical fiber through a third combiner.

7. The same band pumped fiber amplifier of claim 6, wherein: The second pump source generates pump light of 940nm or 976nm; the third combiner is used for coupling the pump light of 940nm or 976nm to the third gain fiber; the third gain fiber is used for absorbing the pump light of 940nm or 976nm to form population inversion; the high reflection fiber grating and the partial reflection fiber grating constitute a laser oscillation cavity, and the partial reflection fiber grating outputs signal light of 1535nm; the fifth isolator is used for forward transmission of the signal light of 1535nm and isolation of backward transmission light.

8. A single stage single pump band pumped fiber amplifier as claimed in any of the claims 6-7, characterized in that: The pump device is coupled between the first isolator and the first gain fiber through the first light combiner to constitute forward pumping or between the first gain fiber and the second isolator to constitute reverse pumping.

9. A single stage single pump band pumped fiber amplifier as claimed in any of the claims 6 to 7, wherein: The pump device is coupled between the first isolator and the first gain fiber through the first light combiner to constitute forward pumping or between the first gain fiber and the second isolator to constitute reverse pumping.

10. A single stage single pump band pumped fiber amplifier as claimed in any of the claims 6 to 7, wherein: The first gain fiber is an erbium-doped single-clad or double-clad fiber; and the third gain fiber is an erbium-doped or erbium-ytterbium co-doped single-clad or double-clad fiber.

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