Far-end pumped erbium-doped fiber amplifier of fiber Raman laser

Abstract

The invention relates to a far-end pumped erbium-doped fiber amplifier of a fiber Raman laser. A 1,550-nanometer laser is a pumping source of the fiber Raman laser and is connected with one end of a pumping transmission fiber by a three-stage high-reflectivity fiber grating, the other end of the pumping transmission fiber is connected with a frequency multiplier by a three-stage low-reflectivity fiber grating, the frequency multiplier is connected with the erbium-doped fiber amplifier, an optical signal is input into the erbium-doped fiber amplifier, an output end of the erbium-doped fiber amplifier is connected with an optical receiver through an optical signal transmission fiber, a central wavelength of the fiber Raman laser is 1,950+ / -2 nanometers, the pumping transmission fiber is a single-mode silicon-based fiber, the length of the pumping transmission fiber is equal to or smaller than 100 kilometers, and the optical signal transmission fiber is directly connected or is connected with the optical receiver through an optical amplifier. By the erbium-doped fiber amplifier, the transmission distance is improved by dozen times compared with direct transmission of 980-nanometer laser, the noise coefficient of the erbium-doped fiber amplifier is reduced by about 1.5dB compared with the noise coefficient of a 1,480-nanometer remote-pumped optical amplifier, and the noise performance of the far-end pumped erbium-doped fiber amplifier is greatly improved.

Description

technical field [0001] The invention relates to an optical fiber amplifier, in particular to an erbium-doped optical fiber amplifier used for remote pumping of an optical fiber Raman laser in a non-relay optical fiber communication system. Background technique [0002] The remote pumped erbium-doped fiber amplifier (referred to as the remote pumped optical amplifier) ​​is the main relay optical amplifier of the unrepeated optical fiber communication system. The light is transmitted to the erbium-doped fiber amplifier (EDFA) for pumping, which has the characteristics that the relay point does not need power supply. The pumping absorption peaks of Erbium-doped fiber amplifier (EDFA) are 980nm and 1480nm, so the pumping sources of 980nm and 1480nm are selected. The EDFA pumped by 1480nm laser has a two-level structure, and the noise figure is relatively high, generally around 6dB. The noise figure of EDFA pumped by ordinary 980 is only 4.5dB or even lower, but the transmissio...

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Problems solved by technology

[0003] In order to overcome the shortcomings of the high noise figure of the 1480nm pump source used in the existing remote-pumped amplifier pumping, the invention provides a remote-pumped erbium-doped fiber amplifier of a fiber Raman laser, and the 1550nm laser is used as the pumping of the fiber Raman laser. The source, the pump transmission fiber is the Raman fiber of the fiber Raman laser, through the multi-level cascaded fiber grating pair and the long-distance pump fiber transmission, forming a 1950nm laser output, entering the frequency doubler, and the frequency is doubled to 980nm laser, as The pump light of the erbium-doped fiber amplifier obtains a lower noise figure and reduces the loss of long-distance transmission

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