The fiber amplifier technology is to dope rare earth elements that can generate laser light into the core of the fiber, and amplify the passed optical signal through the direct current light excitation provided by the laser. The traditional optical fiber transmission system uses optical-electrical-optical regenerative repeaters. This kind of relay equipment affects the stability and reliability of the system. To remove the above conversion process and directly amplify and transmit the signal on the optical path, it is necessary to use An all-optical transmission repeater to replace this regenerative repeater. Applicable equipment includes an erbium-doped fiber amplifier, praseodymium-doped fiber amplifier, niobium-doped fiber amplifier, and Raman optical amplifiers.
Here is the content list:
Advantages of Raman optical amplifiers.
The development of Raman optical amplifiers.
The improvement direction of Raman optical amplifiers.
Advantages of Raman optical amplifiers
Compared with other types of optical amplifiers, the Raman optical amplifiers have many advantages:
(1) The wavelength of the gain light of the Raman optical amplifiers depends on the wavelength of the pump light. In theory, as long as the appropriate wavelength of the pump light is selected, any optical signal band can be amplified, thereby realizing full-band Raman amplification.
(2) high saturation power, when the power of the amplified signal begins to approach the magnitude of the pump power, decrease the size of the optical gain is only a 3d B.
(3) a Raman optical amplifier’s gain spectrum with additive effect, the multi-way pump can be obtained at the same time a broad Raman gain spectrum, single wavelength Raman gain spectrum will compensate each other, achieve gain flatness effect, ensure the stability of the signal transmission.
(4) low noise figure, EDFA hybrid amplifier with Raman optical amplifiers can greatly enhance the performance of the transmission system.
(5) and are very different EDFA, Raman optical amplifiers gain does not require special media, as long as the ordinary transmission fiber can achieve an optical signal amplification so that they can realize the distributed amplification, directly on the optical amplification system expansion and upgrade, rational use of low-loss window associated improvement of the optical fiber and the like.
Many advantages above also determine the Raman optical amplifiers can be widely applied in a WDM optical communication system.
The development of Raman optical amplifiers
In the application scenario, when the span is not very long, usually only the first-order Raman optical amplifiers are generally used, and the second-order Raman optical amplifiers are dedicated to long-distance optical transmission systems and dense wavelength division multiplexing optical transmission. The optical signal amplification of the system is used to enhance the gain of the ordinary Raman amplification system. With the characteristics of large bandwidth, high gain, and low noise, it effectively increases the performance of the Raman optical amplifiers and is more suitable for long-distance non-relay fiber communication systems. The second-order Raman optical amplifiers are based on the first-order Raman optical amplifiers, adding a 13nm window of pump light. The 13nm pump light first amplifies the 14nm pump light, and the 14nm pump light then amplifies 1550. The signal light in the waveband, so that Raman amplification appears twice in the optical fiber. The key here is that 13nm pump light and 14nm pump light do not directly irradiate the fiber at the same time, but 13nm to irradiate 14nm, and 14nm pump light to irradiate the fiber. After introducing the second-order pump, the power of the first-order pump is allowed to be very low, so that the high-power second-order pump becomes the main energy supply, and it is easy to achieve high gain. According to the different incident positions of the first-order and second-order pumps, the second-order Raman optical amplifiers are divided into a second-order backward pumping method and a second-order forward pumping method. Second-order backward pumping: focus on the output to amplify the signal. Second-order forward pumping: Both the signal light input end and the output end can amplify the signal to form a two-way pump, which can better reduce the interference between the signal and the pump light than the conventional two-way pump amplification.
The improvement direction of the Raman optical amplifiers
(1) Insufficient gain bandwidth;
(2) Low output gain;
(3) The output gain is not flat.
At last
The Raman optical amplifiers produced by our company comply with international standards and have been investing in the research and development of new Raman optical amplifiers. If you need it, please visit our company’s official website to contact us.
Post time: 12-06-2021