CN210899183U

CN210899183U - Optical structure of remote gain module

Info

Publication number: CN210899183U
Application number: CN201922269405.6U
Authority: CN
Inventors: 迟荣华; 田婧妍
Original assignee: Wuxi Hannuo Photoelectric Technology Co ltd
Current assignee: Wuxi Hannuo Photoelectric Technology Co ltd
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2020-06-30
Anticipated expiration: 2029-12-17

Abstract

The utility model provides an optical structure of a remote gain module, which comprises an input port connected with the input end of an isolator, an output end of the isolator connected with the input end of a first fiber grating, an output end of the first fiber grating connected with the signal end of a first wave combiner, and a reflection end of the first wave combiner connected with the reflection end of a second wave combiner; the common end of the first wave combiner is connected with one end of the erbium-doped fiber, the other end of the erbium-doped fiber is connected with the input end of the second fiber bragg grating, and the output end of the second fiber bragg grating is connected with the signal end of the second wave combiner; the common terminal of the second multiplexer is connected to the output port. The utility model is suitable for a with the enlarged condition of long-range remote pump of fine, under the condition that does not increase long-range pumping power, can effectively improve the gain of long-range gain module, prolong the distance between this long-range gain module and the long-range pumping end, and then the extension does not have relay system's single span distance.

Description

Optical structure of remote gain module

Technical Field

The utility model belongs to the technical field of the optical communication technique and specifically relates to be fit for being arranged in having the long-range circumstances of enlargiing of relay optical transmission system with fine, can improve the gain of long-range gain module.

Background

In special application occasions of submarine transmission or land, due to the limitation of natural conditions, an active relay and monitoring system cannot be established in a transmission link; or the operation and maintenance cost after using the active relay is not affordable for the operator, the transmission distance of the single-span unrepeatered system must be increased. The main limiting factors of the distance of the unrepeatered transmission system are: limited signal power (the signal power at the receiving end is too low to meet the minimum sensitivity requirement of the receiver), limited optical signal-to-noise ratio (OSNR), limited dispersion and limited nonlinearity (e.g., stimulated raman scattering SRS, stimulated brillouin scattering SBS, etc.).

The gain module of the remote amplifier is usually placed in the middle of the transmission line, and when the transmission signal enters the gain module, its power is generally low, and the signal needs to be amplified for further transmission to the receiving end. The pump light of the remote amplifier is separated from the remote gain module and needs to be transmitted to the remote gain module through a section of transmission fiber. When transmitting through the same fiber, the pump light is usually located at the receiving end, and the pump light is sent to the remote gain module from the reverse direction. The noise figure of the counter pump is typically higher for the amplifier. In addition, when the length of the transmission optical fiber is too long, the optical power transmitted to the remote gain module is small, and the gain generated in the gain module is small; when the length of the transmission optical fiber is too short, although the power of the pump light reaching the remote gain module is relatively large, the effect of extending the unrepeatered transmission distance is limited, so that various methods are needed to improve the gain of the gain module, one of the methods is to further increase the remote pump power of a transmitting end (a receiving end), but when the pump power exceeds 1W, serious spontaneous raman lasing occurs in the optical fiber, interference is caused to transmission signals, and error codes occur in a transmission system.

Disclosure of Invention

To exist not enough among the prior art, the utility model provides an optical structure of long-range gain module is particularly useful for with the long-range circumstances of enlargiing of fine, under the circumstances that does not increase long-range pumping power, the gain of improvement long-range optical amplifier that can be great, the distance between this long-range gain module of extension and receiving terminal (long-range pumping end), and then the transmission distance of extension no relay transmission system, its effect is not only can improve the pumping availability factor, can save system's cost moreover.

An optical structure of a remote gain module, comprising:

the fiber grating coupler comprises an input port, an isolator, a first fiber grating, a first wave combiner, an erbium-doped fiber, a second fiber grating, a second wave combiner and an output port;

the input port is connected with the input end of the isolator, the output end of the isolator is connected with the input end of the first fiber bragg grating, the output end of the first fiber bragg grating is connected with the signal end of the first wave combiner, and the reflection end of the first wave combiner is connected with the reflection end of the second wave combiner; the common end of the first wave combiner is connected with one end of the erbium-doped fiber, the other end of the erbium-doped fiber is connected with the input end of the second fiber bragg grating, and the output end of the second fiber bragg grating is connected with the signal end of the second wave combiner; and the common end of the second wave combiner is connected with the signal output end.

Furthermore, the first fiber grating and the second fiber grating are both reflection type, the reflection center wavelength is 1533nm, the reflectivity is 95%, and the 3dB bandwidth is 0.2 nm.

Furthermore, the wavelength range of the signals amplified by the remote gain module is 1570-1610 nm;

furthermore, the erbium-doped fiber is an L-band erbium-doped fiber, the absorption efficiency at 1530nm is 25-30 dB/m, and the length is 7 m.

Furthermore, the reflection end of the first wave combiner (4) is directly connected with the reflection end of the second wave combiner (7).

Further, the remote gain module is suitable for a relay-free remote pump system with optical fiber transmission.

The utility model has the advantages that: the utility model discloses a long-range gain module can be used for with the application scenario of fine remote pump, under the condition that does not increase long-range pumping power, the gain of the long-range gain module of improvement that can be great, the distance between this long-range gain module of extension and the receiving terminal, and then the single span distance that the extension does not have relay transmission system has not only improved the pumping availability factor, has saved the system cost moreover. The remote gain module is arranged at a certain distance from the receiving end, does not need power supply, and has the characteristics of high efficiency and low cost.

Drawings

Fig. 1 is a schematic view of the structure of the present invention.

Detailed Description

The invention is further described with reference to the following specific drawings and examples.

As shown in fig. 1, the present invention provides an optical structure of a remote gain module, including: the fiber grating coupler comprises an input port (1), an isolator (2), a first fiber grating (3), a first combiner (4), an erbium-doped fiber (5), a second fiber grating (6), a second combiner (7) and an output port (8);

the input port (1) is connected with the input end of the isolator (2), the output end of the isolator (2) is connected with the input end of the first fiber bragg grating (3), the output end of the first fiber bragg grating (3) is connected with the signal end of the first wave combiner (4), and the reflection end of the first wave combiner (4) is connected with the reflection end of the second wave combiner (6); the common end of the first wave combiner (4) is connected with one end of an erbium-doped fiber (5), the other end of the erbium-doped fiber (5) is connected with the input end of a second fiber grating (6), and the output end of the second fiber grating (6) is connected with the signal end of a second wave combiner (7); the common end of the second wave combiner (7) is connected with the signal output end (8).

The remote gain module is an L-band optical amplifier; the method can be applied to the application occasions of same-fiber remote pump amplification;

input signal light enters from an input port 1; the pump light enters from the output port 8 through a section of transmission optical fiber, and the output port 8 is also used as an output port of the amplified signal light;

for L-band input signal light, the wavelength range is 1570-1610 nm, and the pump light wavelength 1480nm emitted by the remote pump laser enters the second signal pump combiner through the connection output port; further, the signal light is amplified in the erbium-doped fiber 5;

the first combiner 4 is used for combining input signal light and pump light, the pump light enters from the common end of the second combiner 7, is directly connected with the reflection end of the first combiner 4 through the reflection end of the second combiner 7, and is sent into the first combiner 4, and then is sent into the erbium-doped optical fiber 5 through the common end of the first combiner 4;

the erbium-doped fiber 5 is an L-band erbium-doped fiber, the absorption efficiency at 1530nm is 25-30 dB/m, and the length of the fiber is 7 m;

the first fiber grating 3 is used for reflecting reverse spontaneous emission (ASE) generated in the erbium-doped fiber, the reflection center wavelength of the first fiber grating is 1533nm, the 3dB bandwidth of the first fiber grating is 0.2nm, and the reflectivity of the first fiber grating is more than 90%; the first fiber bragg grating can feed back reverse ASE light to the erbium-doped fiber 5 to further form L-waveband signal light with longer wavelength, and the gain of the erbium-doped fiber 5 can be improved by utilizing the reverse ASE;

the reflection center wavelength of the second fiber grating 6 is 1533nm, the 3dB bandwidth is 0.2nm, and the reflectivity is more than 90%. The function of the erbium-doped fiber is to reflect the forward ASE light to enter the erbium-doped fiber again, and the gain of the erbium-doped fiber can be improved by utilizing the forward ASE light power. The two fiber gratings fully utilize the forward ASE optical power and the reverse ASE optical power to jointly improve the gain of the L-waveband signal.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the examples, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the scope of the claims of the present invention.

Claims

1. An optical structure of a remote gain module, comprising: the fiber grating coupler comprises an input port (1), an isolator (2), a first fiber grating (3), a first combiner (4), an erbium-doped fiber (5), a second fiber grating (6), a second combiner (7) and an output port (8);

the input port (1) is connected with the input end of the isolator (2), the output end of the isolator (2) is connected with the input end of the first fiber bragg grating (3), the output end of the first fiber bragg grating (3) is connected with the signal end of the first wave combiner (4), and the reflection end of the first wave combiner (4) is connected with the reflection end of the second wave combiner (7); the common end of the first wave combiner (4) is connected with one end of an erbium-doped fiber (5), the other end of the erbium-doped fiber (5) is connected with the input end of a second fiber grating (6), and the output end of the second fiber grating (6) is connected with the signal end of a second wave combiner (7); the common end of the second wave combiner (7) is connected with the output port (8).

2. The optical structure of a remote gain module as set forth in claim 1,

the first fiber grating (3) and the second fiber grating (6) are both reflection type, the reflection center wavelength is 1533nm, the reflectivity is 95%, and the 3dB bandwidth is 0.2 nm.

3. The optical structure of a remote gain module as set forth in claim 1,

the wavelength range of the signals amplified by the remote gain module is 1570-1610 nm.

4. The optical structure of a remote gain module as set forth in claim 1,

the erbium-doped fiber (5) is an L-band erbium-doped fiber, the absorption efficiency at 1530nm is 25-30 dB/m, and the length is 7 m.

5. A remote gain module optical structure as claimed in claim 1, characterized in that the reflecting end of the first wave combiner (4) is directly connected to the reflecting end of the second wave combiner (7).

6. The optical architecture of a remote gain module of claim 1, wherein the unrepeatered remote pump system is adapted for co-fiber transmission.