CN215896959U

CN215896959U - Light path structure of L-band small-signal bidirectional amplifier

Info

Publication number: CN215896959U
Application number: CN202122446290.0U
Authority: CN
Inventors: 李潇; 王健男; 华晓俊; 李现勤
Original assignee: Wuxi Dekeli Optoelectronic Technology Co ltd
Current assignee: Wuxi Dekeli Optoelectronic Technology Co ltd
Priority date: 2021-10-09
Filing date: 2021-10-09
Publication date: 2022-02-22
Anticipated expiration: 2031-10-09

Abstract

The utility model discloses an L-band small-signal bidirectional amplifier optical path structure, which relates to the technical field of optical fiber amplifiers and comprises an input/output port, a bidirectional optical splitter, a multiplexer, an erbium optical fiber, a filter, a pumping optical splitter, a pumping source and a photodetector; the small signal enters through the input port, the main path of the bidirectional optical splitter transmits a main signal, the multiplexer amplifies a pumping signal, the filter filters out-of-band ASE, and the photodetector detects an input optical signal and an output optical signal. The optical path structure can effectively amplify the L-waveband small signal, improves the adverse effect caused by spontaneous radiation light through the filter, and reduces the influence of overlarge pumping output power when the L-waveband small signal is amplified; and through the two-way pumping light splitting structure, the two-way amplification light path is realized by using limited devices, and the production material cost is reduced.

Description

Light path structure of L-band small-signal bidirectional amplifier

Technical Field

The utility model relates to the technical field of optical fiber amplifiers, in particular to an L-band bidirectional amplifier optical path structure.

Background

Due to the rapid increase of network communication traffic, each operator gradually expands the communication capacity to the L-band, and the application of EDFA will play a key role in order that the L-band signal can be applied in the long-distance transmission scenario. EDFAs are commonly used for amplification of signals in the C-band (1530nm-1565nm), mainly due to the higher gain spectral coefficient of erbium fibers in this band; whereas when erbium fiber is used for amplification in L band (long wavelength band: 1570nm-1630nm), conventional applications require longer, higher concentrations of erbium fiber to be used in the product due to low population inversion and lower absorption and gain coefficients. In practical application, in order to reduce absorption loss and energy accumulation of spontaneous emission, a pump splitting optical path is adopted for signal amplification, but when an L-band signal is sufficiently small, a lot of pump power is wasted for amplification by adopting the pump splitting optical path, and the phenomenon of small-signal amplified spontaneous emission is enhanced.

SUMMERY OF THE UTILITY MODEL

The utility model provides an optical path structure of an L-band bidirectional amplifier aiming at the problems and the technical requirements, and the technical scheme of the utility model is as follows:

an optical path structure of an L-band small-signal bidirectional amplifier comprises: the erbium-doped fiber laser comprises a pumping source, a pumping light splitting device, a first bidirectional light splitter, a second bidirectional light splitter, first to sixth multiplexers, a first filter, a second filter and first to fourth erbium fibers; the first bidirectional optical splitter is connected with one end of a first multiplexer, the other end of the first multiplexer is connected with a first filter through a first erbium fiber, the reflection end of the first filter is connected with one end of a second multiplexer, the other end of the second multiplexer is connected with one end of a third multiplexer through a second erbium fiber, the other end of the third multiplexer is connected with one end of a fourth multiplexer, the other end of the fourth multiplexer is connected with one end of a fifth multiplexer through a third erbium fiber, the other end of the fifth multiplexer is connected with the reflection end of a second filter, the second filter is connected with one end of a sixth multiplexer through a fourth erbium fiber, and the other end of the sixth multiplexer is connected with the second bidirectional optical splitter; the pump source pumps the first multiplexer and the second multiplexer in a forward direction and pumps the fifth multiplexer and the sixth multiplexer in a backward direction through the pump light splitting device.

Furthermore, the pump beam splitting device comprises a first pump beam splitter, a second pump beam splitter, a third pump beam splitter, a pump source and a pump source.

The first optical detector and the fourth optical detector are respectively connected to two ends of the first bidirectional optical splitter; and the second light detector and the third light detector are respectively connected to two ends of the second bidirectional optical splitter.

Further, the transmission ends of the first filter and the second filter are connected with optical fibers wound by a plurality of circles; and the pump signals of the third multiplexer and the fourth multiplexer are terminated by a plurality of circles of optical fibers.

Furthermore, the number of turns of the small circle is 10-15, and the diameter of the small circle is 5-10 mm.

Further, the first pump beam splitter splits the light output by the pump source into two parts, namely 50% and 50%.

Further, the splitting ratio of the second pump beam splitter input to the first multiplexer is the same as the splitting ratio of the third pump beam splitter input to the sixth multiplexer; the splitting ratio of the second pump optical splitter input to the second multiplexer is the same as the splitting ratio of the third pump optical splitter input to the fifth multiplexer.

Further, input light is input into the first bidirectional optical splitter through an input port and is transmitted to an output port by the second bidirectional optical splitter; or the input light is transmitted to the output port through the input port and the input second bidirectional optical splitter by the first bidirectional optical splitter.

The beneficial technical effects of the utility model are as follows:

the application discloses an L-waveband small-signal bidirectional amplifier optical path structure which can effectively amplify an L-waveband small signal, improve adverse effects caused by spontaneous radiation light through a filter and reduce the influence of overlarge pumping output power when the L-waveband small signal is amplified; meanwhile, a bidirectional amplifying light path is realized by using limited devices through a bidirectional pumping light splitting structure, and the production material cost is reduced.

Drawings

Fig. 1 is a schematic diagram of an optical path structure of an L-band small-signal bidirectional amplifier of the present invention.

Detailed Description

The following further describes the embodiments of the present invention with reference to the drawings.

The application discloses two-way amplifier light path structure of L wave band small signal includes: the erbium-doped fiber laser comprises a pump source, first to third pump optical splitters, a first bidirectional optical splitter, a second bidirectional optical splitter, first to sixth multiplexers, a first filter, a second filter and first to fourth erbium fibers.

Since the bidirectional optical path is symmetrical with respect to the left and right optical paths, for convenience of description, the following description of the embodiments is defined as being performed with input light from left to right; the condition of the input light from right to left is consistent with the condition, and the description is not repeated.

As shown in fig. 1, the optical circuit structure of this embodiment is connected such that the input port (101) is connected to the first bidirectional optical splitter (102), the secondary output port of the first bidirectional optical splitter (102) is connected to the first photodetector, the main output port of the first bidirectional optical splitter (102) is connected to one end of the first multiplexer (103), the other end of the first multiplexer (103) is connected to the first filter (105) through the first erbium fiber (104), the reflection end of the first filter (105) is connected to one end of the second multiplexer (106), the other end of the second multiplexer (106) is connected to one end of the third multiplexer (108) through the second erbium fiber (107), the other end of the third multiplexer (108) is connected to one end of the fourth multiplexer (109), the other end of the fourth multiplexer (109) is connected to one end of the fifth multiplexer (111) through the third erbium fiber (110), and the other end of the fifth multiplexer (111) is connected to the second filter (112), the reflecting end of the second filter (112) is connected with one end of a sixth multiplexer (114) through a fourth erbium optical fiber (113), the other end of the sixth multiplexer (114) is connected with a second bidirectional optical splitter (115), the main output end of the second bidirectional optical splitter (115) is connected with an output port (116), and the secondary output end of the second bidirectional optical splitter (115) is connected with a second optical detector.

The pump source (117) is connected with the first pump optical splitter (118), and the output end of the first pump optical splitter (118) is connected with the second pump optical splitter (119) and the third pump optical splitter (120); preferably, the pump source (117) equally divides the pump power to the second pump splitter (119) and the third pump splitter (120) through the first pump splitter (118), i.e. the first pump splitter (118) divides the light output by the pump source (117) into two parts, 50% and 50%. The output end of the second pump optical splitter (119) is connected with the pump end of the first multiplexer (103) and the pump end of the second multiplexer (106), and the output end of the third pump optical splitter (120) is connected with the pump end of the fifth multiplexer (111) and the pump end of the sixth multiplexer (114). The second pump optical splitter (119) pumps the first erbium fiber (104) and the second erbium fiber (107) in forward direction through the first multiplexer (103) and the third multiplexer (106); the third pump splitter (120) reversely pumps the third erbium fiber (110) and the fourth erbium fiber (113) through the fifth multiplexer (111) and the sixth multiplexer (114). Preferably, the splitting ratio of the second pump beam splitter (119) input to the first multiplexer (109) is the same as the splitting ratio of the third pump beam splitter (120) input to the sixth multiplexer (114); the splitting ratio of the second pump splitter (119) input to the second multiplexer (106) is the same as the splitting ratio of the third pump splitter (120) input to the fifth multiplexer (111).

Preferably, the transmission ends of the first filter (105) and the second filter (112) are connected with optical fibers wound by a plurality of circles; the pumping signal ends of the third multiplexer (108) and the fourth multiplexer (109) are also connected with the optical fiber wound by a plurality of circles of small circles; the number of turns of the small circle is 10-15, and the diameter is 5-10 mm.

The working process of the optical path structure of the embodiment is as follows: small signal input light enters through an input port (101), a main signal is transmitted by a main output end of a first bidirectional optical splitter (102), and a secondary output end of the first bidirectional optical splitter (102) is connected to a first optical detector for input light detection; the pump light and the signal light are pumped forward by a first multiplexer (103) for primary amplification, the amplified signal light comprises an amplified signal and out-of-band spontaneous emission (ASE) power, and the out-of-band ASE power accounts for main output; the out-of-band ASE can be transmitted to the transmission end through the first filter (105), the out-of-band ASE power is leaked by the transmission end, and the in-band primary amplification signal is transmitted through the reflection port of the first filter (105) in a main path; the primary amplification signal is subjected to forward pumping secondary amplification through a second multiplexer (106), in-band signal amplification occupies the main output, but the secondary amplification signal may contain pump light and needs to leak the pump light through a third multiplexer (108); the secondary amplified signal is transmitted to a third erbium fiber (110) through a fourth multiplexer (109), the fifth multiplexer (111) reversely transmits the pump light to the third erbium fiber (110), the secondary amplified signal is reversely pumped and amplified into a third amplified signal, and redundant pump light needs to be leaked through the fourth multiplexer (109) due to reverse pumping; the third amplified signal can transmit the out-of-band ASE to the transmission end through the second filter (112), the transmission end leaks the out-of-band ASE power, and the in-band third amplified signal carries out main path transmission through the reflection port of the second filter (112); the sixth multiplexer (114) reversely pumps the fourth erbium fiber (113), and the signal is amplified into a fourth amplified signal; the main path signal is connected with the second optical detector through the secondary output end of the second bidirectional optical splitter (115) to detect output light, and the main path signal is transmitted to the output port (116) through the main output end of the second bidirectional optical splitter (115).

The method for leaking out-of-band ASE power at the transmission ends of the first filter (105) and the second filter (112) is to wind the optical fiber of the port for a small circle to destroy the total emission transmission condition in the optical fiber and leak light; similarly, the method for leaking the redundant pump light from the pump signal end of the third multiplexer (108) and the fourth multiplexer (109) is to wind the optical fiber of the port by a small circle to destroy the full-emission transmission condition in the optical fiber and leak the light.

When the input light of the bidirectional optical path is from right to left, the secondary output end of the second bidirectional optical splitter (115) is connected with the third optical detector to perform input light detection, and the secondary output end of the first bidirectional optical splitter (102) is connected with the fourth optical detector to perform output light detection.

What has been described above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiment. It is to be understood that other modifications and variations directly derivable or suggested by those skilled in the art without departing from the spirit and concept of the present invention are to be considered as included within the scope of the present invention.

Claims

1. An optical path structure of an L-band small-signal bidirectional amplifier, comprising: the erbium-doped fiber laser comprises a pumping source, a pumping light splitting device, a first bidirectional light splitter, a second bidirectional light splitter, first to sixth multiplexers, a first filter, a second filter and first to fourth erbium fibers; the first bidirectional optical splitter is connected with one end of a first multiplexer, the other end of the first multiplexer is connected with a first filter through a first erbium fiber, the reflection end of the first filter is connected with one end of a second multiplexer, the other end of the second multiplexer is connected with one end of a third multiplexer through a second erbium fiber, the other end of the third multiplexer is connected with one end of a fourth multiplexer, the other end of the fourth multiplexer is connected with one end of a fifth multiplexer through a third erbium fiber, the other end of the fifth multiplexer is connected with the reflection end of a second filter, the second filter is connected with one end of a sixth multiplexer through a fourth erbium fiber, and the other end of the sixth multiplexer is connected with the second bidirectional optical splitter; the pump source pumps the first multiplexer and the second multiplexer in a forward direction and pumps the fifth multiplexer and the sixth multiplexer in a backward direction through the pump light splitting device.

2. The optical path structure of an L-band small-signal bidirectional amplifier according to claim 1, wherein the pump splitter device includes first to third pump splitters, the pump source is connected to the first pump splitter, an output end of the first pump splitter is connected to the second pump splitter and the third pump splitter, an output end of the second pump splitter is connected to the pump end of the first multiplexer and the pump end of the second multiplexer, and an output end of the third pump splitter is connected to the pump end of the fifth multiplexer and the pump end of the sixth multiplexer.

3. The optical path structure of an L-band small-signal bidirectional amplifier according to claim 1, further comprising first to fourth optical detectors, the first optical detector and the fourth optical detector being respectively connected to two ends of the first bidirectional optical splitter; and the second light detector and the third light detector are respectively connected to two ends of the second bidirectional optical splitter.

4. The optical circuit structure of an L-band small-signal bidirectional amplifier according to claim 1, wherein the transmission ends of the first and second filters are connected to the optical fiber wound in several small turns; and the pump signals of the third multiplexer and the fourth multiplexer are terminated by a plurality of circles of optical fibers.

5. The optical path structure of an L-band small-signal bidirectional amplifier according to claim 4, wherein the number of turns is 10-15, and the diameter of the small turn is 5-10 mm.

6. The optical circuit structure of an L-band small-signal bidirectional amplifier according to claim 2, wherein the first pump splitter splits the light output from the pump source into two parts, 50% and 50%.

7. The optical circuit structure of an L-band small-signal bidirectional amplifier according to claim 2, wherein the splitting ratio of the second pump splitter input to the first multiplexer is the same as the splitting ratio of the third pump splitter input to the sixth multiplexer; the splitting ratio of the second pump optical splitter input to the second multiplexer is the same as the splitting ratio of the third pump optical splitter input to the fifth multiplexer.

8. The optical path structure of an L-band small-signal bidirectional amplifier according to claim 1, wherein input light is input to the first bidirectional optical splitter through an input port and transmitted to an output port by the second bidirectional optical splitter; or the input light is transmitted to the output port through the input port and the input second bidirectional optical splitter by the first bidirectional optical splitter.