DWDM remote pumping system capable of improving OSNR

Patent metadata

Field	Value
Publication number	US-11265098-B2
Application number	US-201817263283-A
Country	US
Kind code	B2
Filing date	Dec 25, 2018
Priority date	Jul 27, 2018
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

The present disclosure relates to optical communications, and in particular, to a DWDM remote pumping system for improving an OSNR. The system includes remote pumping gain unit, preamplifier, and gain flattening filter sequentially connected. Remote pumping gain unit and preamplifier are cascaded one behind the other as a whole amplifier. Gain flattening filter is disposed at the preamplifier's output end. In the system, remote gain unit and preamplifier which have large impact on the OSNR of the entire system are optimally designed as a whole amplifier. In remote gain unit, gain flattening filter originally disposed between two erbium-doped fiber segments is moved back to preamplifier's output end for significant improvement of gain and noise figures of the remote gain unit while ensuring gain flatness of the entire transmission system, thus effectively improving the entire system's OSNR, improving operation stability and reliability, effectively reducing bit error rate, and facilitating system maintenance.

First claim

What is claimed is:

1. A DWDM remote pumping system capable of improving an OSNR, wherein the DWDM remote pumping system comprises a remote pumping gain unit, a preamplifier, and a gain flattening filter connected in sequence, the remote pumping gain unit and the preamplifier are cascaded to form a cascade amplifier, and the gain flattening filter is provided at an output end of the preamplifier,
wherein the DWDM remote pumping system further comprises a pumping unit, and an optical transmitter array, an optical multiplexer, a power amplifier, a first transmission fiber, a second transmission fiber, an optical demultiplexer and an optical receiver array, which are connected in sequence; wherein the pumping unit is connected to the remote pumping gain unit for providing pumping light to the remote pumping gain unit,
wherein the remote pumping gain unit is a foreign fiber pumping gain unit, and the optical transmitter array, the optical multiplexer, the power amplifier, the first transmission fiber, the remote pumping gain unit, the second transmission fiber, the preamplifier, the gain flattening filter, the optical demultiplexer and the optical receiver array are connected in sequence; wherein the remote pumping system further comprises a third transmission fiber which is separately provided, and the pumping unit transmits the pumping light to the remote pumping gain unit through the third transmission fiber,
wherein the remote pumping gain unit includes a signal input end optical isolator, a signal/pumping multiplexer, a first erbium-doped fiber, an intermediate optical isolator, a second erbium-doped fiber, a pumping mirror, and a signal output end optical isolator, which are connected in sequence; and wherein signal light enters the remote pumping gain unit through the signal input end optical isolator, and is output through the signal output end optical isolator after being amplified; the pumping light directly enters the remote pumping gain unit through the third transmission fiber to realize forward pumping, then the pumping light and the signal light are coupled, by the signal/pumping multiplexer, into the erbium-doped fiber to be amplified, finally, remaining pumping light is reflected by the pump mirror back to an original line.

2. The DWDM remote pumping system capable of improving an OSNR of claim 1 , wherein
the remote pumping system is a same fiber pumping system or a foreign fiber pumping system, and the same fiber pumping system and the foreign fiber pumping system both use a way of forward pumping.

3. The DWDM remote pumping system capable of improving an OSNR of claim 1 , wherein a wavelength of the pumping light generated by the pumping unit is 1460-1490 nm.

4. The DWDM remote pumping system capable of improving an OSNR of claim 1 , wherein the remote pumping gain unit is a same fiber pumping gain unit, and
the optical transmitter array, the optical multiplexer, the power amplifier, the first transmission fiber, the remote pumping gain unit, the second transmission fiber, the pumping unit, the preamplifier, the gain flattening filter, the optical demultiplexer and the optical receiver array are connected in sequence;
wherein the pumping unit reversely transmits the pumping light to the remote pumping gain unit through the second transmission fiber.

5. The DWDM remote pumping system capable of improving an OSNR of claim 4 , wherein the remote pumping gain unit includes a signal input end optical isolator,
a signal/pumping multiplexer, a first erbium-doped fiber, an intermediate optical isolator, a second erbium-doped fiber, a pumping mirror, a signal output end optical isolator, and a pumping/signal multiplexer, which are connected in sequence;
wherein signal light enters the remote pumping gain unit through the signal input end optical isolator, and is output through the signal output end optical isolator after being amplified; and the pumping light is separated by the pumping/signal multiplexer, then the signal/pumping multiplexer couples separated pumping light and the signal light into the erbium-doped fiber, finally remaining pumping light is reflected back to an original line by the pumping mirror.

6. The DWDM remote pumping system capable of improving an OSNR of claim 1 , wherein an adjustable optical attenuator is further provided between the first erbium-doped fiber and the second erbium-doped fiber, and power gain provided by the first erbium-doped fiber is greater than insertion loss of the adjustable optical attenuator.

7. The DWDM remote pumping system capable of improving an OSNR of claim 1 , wherein the preamplifier adopts an erbium-doped fiber amplifier or a Raman amplifier.

8. The DWDM remote pumping system capable of improving an OSNR of claim 5 , wherein an adjustable optical attenuator is further provided between the first erbium-doped fiber and the second erbium-doped fiber, and power gain provided by the first erbium-doped fiber is greater than insertion loss of the adjustable optical attenuator.

Assignees

• Accelink Tech Co Ltd

Inventors

• Fu Chengpeng
• Tao Jintao
• Chen Jun
• Le Menghui
• Yu Chunping

Classifications

• H04J14/0221 Primary

  Power control, e.g. to keep the total optical power constant · CPC title

• H04B10/07953

  Monitoring or measuring OSNR, BER or Q · CPC title

• H04B10/2941 Primary

  using an equalising unit, e.g. a filter (H04B10/296 takes precedence) · CPC title

• H04J14/0254

  Optical medium access · CPC title