CN208782238U

CN208782238U - It can be improved the light channel structure of Raman Fiber Amplifier unicast control precision

Info

Publication number: CN208782238U
Application number: CN201821724881.1U
Authority: CN
Inventors: 王雷
Original assignee: Wuxi Taclink Optoelectronics Technology Co Ltd
Current assignee: Wuxi dekeli Optoelectronic Technology Co.,Ltd.
Priority date: 2018-10-24
Filing date: 2018-10-24
Publication date: 2019-04-23
Anticipated expiration: 2028-10-24

Abstract

The utility model belongs to optical technical field, relate to improve the light channel structure of Raman Fiber Amplifier unicast control precision, including pump signal wave multiplexer, light splitting coupler, pump laser group, photodiode, signal light accesses the common end of pump signal wave multiplexer by transmission fiber, the reflection end of pump signal wave multiplexer is connected with the output end of pump laser group, the input terminal of the transmission end insertion gain flat filter of pump signal wave multiplexer, the output end of gain smoothing filter is connected with the common end of light splitting coupler, the auxiliary light splitting end of light splitting coupler is connected with photodiode, the main light splitting end of light splitting coupler is the output end of RFA module by signal light；The utility model is by introducing gain smoothing filter, when FRA work is in constant pumping power mode, the light channel structure can compensate automatically changes caused change in gain by signal wavelength, so that RFA, in low level signal amplification section, the gain of unlike signal wavelength is held essentially constant.

Description

It can be improved the light channel structure of Raman Fiber Amplifier unicast control precision

Technical field

The utility model relates to a kind of light channel structures, specifically a kind of for improving Raman Fiber Amplifier unicast gain Control the light channel structure of precision.

Background technique

Raman Fiber Amplifier (RFA:Raman Fiber Amplifier) can optimize light noise since noise figure is low Than (OSNR:Optical Signal Noise Ratio), reduce the bit error rate, increases transmission range, be now widely used for growing In optical communication Transmission system.

For a certain pumping wavelength, the small signaling switch gain of RFA can be indicated by formula (1):

Wherein, g_RIt is related to signal wavelength for optical fiber Raman gain coefficienct；A_effFor optical fiber effective area；P_pTo enter fine pump Pu power；K is polarization factor；L_effFor optical fiber effective length, it is defined as L_eff=1-exp (- α^pL)/α_p；α_pIt is pump light in light Attenuation coefficient in fibre；L is fiber lengths, small signal refer to signal power it is small to will not influence pump power in a fiber point Cloth.

Traditional RFA operating mode is permanent pump power mode, that is, enters fine pump power P_pIt is constant.It can by formula (1) Know, when RFA work is at small signal-wire amplification region: if signal wavelength is constant, signal gain is constant；When signal wavelength changes When, due to the corresponding Raman gain coefficienct g of unlike signal wavelength_RDifference, signal gain can vary widely；Unlike signal wave Long corresponding gain is different, if system margin is smaller, since OSNR is poor, receiver may in gain lesser (wavelength) channel There is error code, Transmission system can not work normally；If the gain of a certain wavelength (channel) is too big, when especially multiple RFA are cascaded, Optical power into receiver causes greatly very much to be saturated, and Transmission system also can not be normal；And the debugging of Transmission system at this time is more numerous It is trivial.

Summary of the invention

The purpose of the utility model is to overcome the deficiencies in the prior art, provide a kind of for improving Raman fiber The light channel structure of amplifier unicast gain control accuracy, by introducing gain smoothing filter, when FRA works in constant pumping function When rate mode, which can compensate automatically changes caused change in gain by signal wavelength, so that RFA is put in small signal The gain in big section, unlike signal wavelength is held essentially constant.

To realize the above technical purpose, the technical solution of the utility model is: can be improved Raman Fiber Amplifier unicast The light channel structure of precision, including pump signal wave multiplexer, light splitting coupler, pump laser group, photodiode are controlled, it is special Sign is that signal light accesses the common end of pump signal wave multiplexer, the reflection of the pump signal wave multiplexer by transmission fiber End is connected with the output end of pump laser group, the input of the transmission end insertion gain flat filter of pump signal wave multiplexer End, the output end of the gain smoothing filter are connected with the common end of light splitting coupler, the auxiliary light splitting of the light splitting coupler End is connected with photodiode, and the main light splitting end of light splitting coupler is the output end of RFA module by signal light.

Further, the pump laser group includes at least one pump laser, the wavelength of multiple pump lasers It may be the same or different.

Further, the light channel structure is suitable for reversed Raman configuration, forward direction Raman configuration and two-way Raman configuration.

Further, the Raman Fiber Amplifier operating mode is permanent pump power mode.

The utility model has the advantage that

1) the utility model in the main optical path of light channel structure by introducing gain smoothing filter GFF, with signal wave Long variation, corresponding gain remain unchanged, i.e. gain and wavelength (channel) is unrelated, and different wave length gain control can be realized The raising of precision processed；

2) Transmission system of the utility model can cover Single wavelength and multi-wavelength system；

3) each signal wavelength gain of the utility model Transmission system is all the same, therefore debugs very simple.

Detailed description of the invention

Fig. 1 is reversed RFA light channel structure schematic diagram.

Fig. 2 is the simulation result curve graph that input optical power of reversed RFA under the conditions of singly pump is -10dbm.

Fig. 3 is the simulation result curve graph that input optical power of reversed RFA under the conditions of singly pump is -30dbm.

Fig. 4 is gain smoothing filter spectral pattern of reversed RFA under the conditions of singly pump.

Fig. 5 is the simulation result curve graph that input optical power of reversed RFA under the conditions of more pumps is -10dbm.

Fig. 6 is the simulation result curve graph that input optical power of reversed RFA under the conditions of more pumps is -30dbm.

Fig. 7 is gain smoothing filter spectral pattern of reversed RFA under the conditions of more pumps.

Description of symbols: 1- transmission fiber, 2- pump signal wave multiplexer, 3- light splitting coupler, 4- pump laser group, 5- photodiode, 6- gain smoothing filter.

Specific embodiment

Below with reference to specific drawings and examples, the utility model is described in further detail.

As shown in Fig. 1, the light channel structure of Raman Fiber Amplifier unicast control precision, including pump signal be can be improved Wave multiplexer 2, light splitting coupler 3, pump laser group 4, photodiode 5, signal light access pump signal by transmission fiber 1 The reflection end of the common end of wave multiplexer 2, the pump signal wave multiplexer 2 is connected with the output end of pump laser group 4, pumping letter The input terminal of the transmission end insertion gain flat filter 6 of number wave multiplexer 2, the output end of the gain smoothing filter 6 with point The common end of photo-coupler 3 is connected, the auxiliary light splitting end (generally small light splitting end) of the light splitting coupler 3 and photodiode 5 It is connected, the main light splitting end (generally big light splitting end) of light splitting coupler 3 is the output end of RFA module by signal light；

Including two pump lasers in pump laser group 4 in the present embodiment, the wavelength of two pump lasers can phase It together, can also be different；And pump signal wave multiplexer 2, light splitting coupler 3, pump laser group 4, photodiode 5 and gain are flat The specific implementation structure of smooth filter 6 is all made of common structure type, specially those skilled in the art in the art Known, details are not described herein again；

Raman Fiber Amplifier operating mode is permanent pump power mode, is emulated by taking reversed RFA as an example, pumping wavelength Be divided into two kinds of situations: a, pumping wavelength are identical；B, pumping wavelength is different.

A, pumping wavelength is identical: the wavelength of two pump lasers is 1450nm in pump laser group 4, is pumped into fibre General power is set as 420mw.Signal is Single wavelength, and wave-length coverage is 1529~1568nm, using 1529nm as reference wavelength, Gain design is 7dB；

Fig. 2 is the simulation result that input optical power is -10dbm, and Fig. 3 is the simulation result that input optical power is -30dbm When, Fig. 4 is spectrum of the GFF with wavelength change；

It can be with it is clear to see that in the absence of the gain smoothing filter 6, with the change of signal wavelength by Fig. 2 and Fig. 3 Change, corresponding gain also varies widely；It is corresponding with the variation of signal wavelength in the presence of gain smoothing filter 6 Gain be held essentially constant；Simultaneously regardless of 6 presence or absence of gain smoothing filter, reference wavelength is the corresponding gain of 1529nm It is 7dB；

Available by Fig. 4, with the variation of signal wavelength, the value of gain smoothing filter 6 accordingly also changes, so that right The gain answered remains unchanged.

B, pumping wavelength is different: in pump laser group 4 wavelength of two pump lasers be respectively 1425nm, 1455nm；Signal is Single wavelength, and wave-length coverage is 1529~1568nm；Using 1529nm as reference wavelength, gain design is 7dB；

The power for adjusting two pump lasers first, so that the gain deviation of different wave length signal is small as far as possible, after adjustment The power of 1425nm pump laser is 134mw, and the power of 1455nm pump laser is 305mw；Keep pump laser function Rate is constant；Fig. 5 is the simulation result that input optical power is -10dbm, when Fig. 6 is the simulation result that input optical power is -30dbm, Fig. 7 is spectrum of the GFF with wavelength change；

It can be with it is clear to see that in the absence of the gain smoothing filter 6, with the change of signal wavelength by Fig. 5 and Fig. 6 Change, corresponding gain also varies widely, and maximum gain differs nearly 1dB or so with least gain；When flat gain is filtered In the presence of wave device 6, the corresponding gain of different wave length is remained unchanged；Regardless of 6 presence or absence of gain smoothing filter, reference wavelength is The corresponding gain of 1529nm is 7dB；

Available by Fig. 7, with the variation of signal wavelength, the value of gain smoothing filter 6 accordingly also changes, so that right The gain answered remains unchanged.

The utility model is by introducing gain smoothing filter 6, so that no matter how wavelength (channel) switches, it is corresponding Gain remains unchanged, i.e., gain and wavelength (channel) are unrelated, therefore the debugging of Transmission system is very simple；The utility model simultaneously When being applicable not only to single wavelength signals, and multiple wavelength signals being simultaneously amplified, the corresponding gain of each wavelength is still protected It holds constant；I.e. the utility model Transmission system can cover Single wavelength and multi-wavelength system；

In addition, above-mentioned conclusion is still correct for preceding to Raman Fiber Amplifier, two-way Raman Fiber Amplifier.Forward direction, The optical texture of two-way Raman Fiber Amplifier is known to those skilled in the art, and details are not described herein again.

The utility model and embodiments thereof are described above, description is not limiting, shown in the drawings It also is one of the embodiments of the present invention, practical structures are not limited thereto.All in all if this field it is common Technical staff is enlightened by it, without deviating from the purpose of the present invention, is not inventively designed and the skill The similar frame mode of art scheme and embodiment, all should belong to the protection range of the utility model.

Claims

1. can be improved the light channel structure of Raman Fiber Amplifier unicast control precision, including pump signal wave multiplexer (2), light splitting Coupler (3), pump laser group (4), photodiode (5), which is characterized in that signal light is accessed by transmission fiber (1) The common end of pump signal wave multiplexer (2), the reflection end of the pump signal wave multiplexer (2) are defeated with pump laser group (4) Outlet is connected, the input terminal of the transmission end insertion gain flat filter (6) of pump signal wave multiplexer (2), the flat gain The output end of filter (6) is connected with the common end of light splitting coupler (3), the auxiliary light splitting end of the light splitting coupler (3) and light Electric diode (5) is connected, and the main light splitting end of light splitting coupler (3) is the output end of RFA module by signal light.

2. can be improved the light channel structure of Raman Fiber Amplifier unicast control precision as described in claim 1, feature exists It include at least one pump laser in, the pump laser group (4), the wavelength of multiple pump lasers can be identical or not Together.

3. can be improved the light channel structure of Raman Fiber Amplifier unicast control precision as described in claim 1, feature exists In the light channel structure is suitable for reversed Raman configuration, forward direction Raman configuration and two-way Raman configuration.

4. can be improved the light channel structure of Raman Fiber Amplifier unicast control precision as described in claim 1, feature exists In the Raman Fiber Amplifier operating mode is permanent pump power mode.