CN104579493A

CN104579493A - Optical transceiver module with digital adjustable SBS suppression function

Info

Publication number: CN104579493A
Application number: CN201510016171.8A
Authority: CN
Inventors: 李略
Original assignee: WUXI ZHONGXING OPTOELECTRONICS TECHNOLOGY Co Ltd
Current assignee: Wuxi dekeli Optoelectronic Technology Co.,Ltd.
Priority date: 2015-01-14
Filing date: 2015-01-14
Publication date: 2015-04-29
Anticipated expiration: 2035-01-14
Also published as: CN104579493B

Abstract

The invention relates to an optical transceiver module with a digital adjustable SBS suppression function. The optical transceiver module with the digital adjustable SBS suppression function is packaged in an XFP mode, and an SBS suppression circuit is integrated inside the module. An input end of the SBS suppression circuit is connected with an MCU controller inside the optical transceiver module and receives pulse width modulation signals, and an output end of the SBS suppression circuit is connected with an EML laser and outputs broadened spectral line driving signals; the spectral line width of optical waves output by a DFB laser in the EML laser is increased by modulating the pulse width modulation signals produced by the MCU controller to a biasing circuit of the EML laser, and therefore an SBS threshold value of the optical transceiver module is improved. The optical transceiver module with the digital adjustable SBS suppression function has the advantages that the minimum volume of SBS suppression circuit is optimized, further the part of circuit can be increased to the inside of the optical transceiver module, and the SBS suppression effect can be optimized through simple digital adjustment; the SBS threshold value of the entire long-span optical transmission system is improved on the premise of not increasing the system size and controlling the cost at the lowest level.

Description

With the optical transceiver module of digital adjustable SBS inhibit feature

Technical field

The present invention relates to a kind of optical transceiver module with digital adjustable SBS inhibit feature, is the optical transceiver module being applied to the transmission of overlength single spanning distance.

Background technology

Current Optical Communication Market competition is more and more fierce, the requirement of optical transceiver module is also being improved constantly, transmission rate is more and more higher, the encapsulation volume of module is more and more less, XFP (10Gb Small Form FactorPluggable) module is when meeting the speed of 10Gb/s, volume and power consumption obtain effective control, are also therefore widely used.XFP module has also gone out many different models according to different application developments, there is short distance 300 meters, the module of 850 nano wave length multimodes, there is the module of 10 kilometer of 1310 nano wave length, also the module of the long range propagation of satisfied 40 kilometers and 80 kilometer 1550 nano wave lengths is had, all the laser adopting EML external modulation in the market in long range propagation module, transmission characteristic and the laser propagation effect of EML laser (Electroabsorption Modulated Laser) are better than DFB (distributed feedback laser) directly modulated lasers, so be used for the transmission of the long distance of high frequency, if but in the use procedure of reality, need the transmission system using overlength span as the transmission of the single spanning distance of 350Km, just needing to increase image intensifer in XFP module rear end improves into fine luminous power, but when incident optical power exceedes certain value time, SBS (stimulated Brillouin scattering) effect can be produced, optical transport can be had a strong impact on, transmission range system not being reached specify.Current suppression SBS effect has multiple, but implements all too complicated, is unfavorable for being integrated in above XFP module, need a kind of integrated level high, debugging is convenient, can be applied in the solution in XFP module, improve the threshold values of SBS, meet extra long distance systematic difference.

Goal of the invention

The object of the invention is the threshold values of the XFP module SBS in the transmission of overlength single span system improving 10Gb/s, a kind of optical transceiver module with digital adjustable SBS inhibit feature is provided, is suppressed by SBS circuit part to be integrated into XFP inside modules, improve module utilance.

According to technical scheme provided by the invention, the optical transceiver module of the digital adjustable SBS inhibit feature of described band is encapsulated as XFP form, inside modules comprises EML laser, laser emission control drive circuit, APD receiver, APD receives Drive and Control Circuit and MCU controller, EML laser is used for utilizing emitted light and exports, EML laser connects MCU controller by laser emission control drive circuit, APD receiver is for receiving light input, APD receiver receives Drive and Control Circuit by APD and connects MCU controller, it is integrated with SBS and suppresses circuit in module, SBS suppresses the input of circuit to connect described MCU controller, receive pulse-width signal, SBS suppresses the output of circuit to connect described EML laser, export broadening spectral line drive singal, the pulse-width signal utilizing MCU controller to produce, is modulated on the biasing circuit of EML laser, increases the breadth of spectrum line of the light wave that Distributed Feedback Laser exports in EML laser, thus improves the threshold values of optical transceiver module SBS.

Described SBS suppresses circuit to comprise: pulse-width signal contact resistance R1 one end that MCU controller exports, the resistance R1 other end is respectively through resistance R2 and electric capacity C1 ground connection, the in-phase input end of the resistance R1 other end also concatenation operation amplifier, the output of operational amplifier connects the inverting input of self and holds through resistance R3 to be connected EML laser optical emitting module LD+ with electric capacity C2.

Adjusted the frequency of the pulse-width signal of generation by the digital register adjusting MCU controller inside, adjustment current-limiting resistance R3 adjusts the amplitude of pulse-width signal, thus inhibition is adjusted to optimum state.

Advantage of the present invention is: SBS can suppress circuit optimization to arrive minimum volume by the present invention, thus this part circuit can be increased to optical transceiver module inside, digital regulatedly SBS inhibition can be reached optimum by simple.Realize not increasing system bulk, cost control, under minimum state, improves the SBS threshold values of whole long span optical transmission system.

Accompanying drawing explanation

Fig. 1 optical transceiver module theory diagram.

Fig. 2 increases the optical transceiver module theory diagram after SBS suppression circuit.

Fig. 3 SBS suppresses circuit theory illustrated example.

Fig. 4 SBS suppresses circuit test device figure.

Fig. 5 does not use SBS to suppress the reverberation spectrogram of circuit.

Reverberation spectrogram after Fig. 6 uses SBS to suppress circuit.

Embodiment

The theory diagram of optical transceiver module is as Fig. 1, be encapsulated as XFP form, inside modules comprises: EML laser, laser emission control drive circuit, APD receiver, APD receive Drive and Control Circuit, MCU controller and power supply and plug-and-play circuit part (not shown), EML laser connects MCU controller by laser emission control drive circuit, and APD receiver receives Drive and Control Circuit by APD and connects MCU controller.EML laser is used for utilizing emitted light and exports, and is adjusted and control laser transmitter circuit EML laser is normally worked by MCU controller.APD receiver for receive light input, adjusted by MCU controller and control ADP receiver make APD hold can normally work.XFP inside modules circuit is complicated, and components and parts are densely distributed, and space is smaller.The SBS that the present invention increases suppresses circuit due to circuit optimization, and integrated level is high, therefore well can be integrated into inside modules.

The brillouin gain of optical fiber and the spectral width △ ν p relation of pump light are very close, if to be Lorentz linear for the spectrum of pump light, its spectrum width is △ ν p, and the spectrum width of stimulated Brillouin scattering is △ ν _b, then stimulated Brillouin scattering peak gain is g` _b=g _b* △ ν _b/ (△ ν _b+ △ ν p), that is, the spectrum width △ ν p of pump light is wider, the peak gain of stimulated Brillouin scattering is lower, so in order to suppress stimulated Brillouin scattering, can modulate pump light, increase the spectrum width of pump light, reduce the gain of Brillouin scattering, improve the threshold values of SBS.

As shown in Figure 2, the present invention is integrated with SBS and suppresses circuit in module, and SBS suppresses the input of circuit to connect described MCU controller, receives pulse-width signal, and SBS suppresses the output of circuit to connect described EML laser, exports broadening spectral line drive singal.The pulse-width signal that the present invention utilizes the inner original MCU controller of optical transceiver module to produce, be modulated on the biasing circuit of EML laser, increase the breadth of spectrum line of the light wave that Distributed Feedback Laser exports in EML laser, thus improve the threshold values of optical transceiver module SBS.

As Fig. 3, described SBS suppresses circuit to comprise: pulse-width signal contact resistance R1 one end that MCU controller exports, the resistance R1 other end is respectively through resistance R2 and electric capacity C1 ground connection, the in-phase input end of the resistance R1 other end also concatenation operation amplifier, the output of operational amplifier connects the inverting input of self and holds through resistance R3 to be connected EML laser optical emitting module TOSA LD+ with electric capacity C2.Utilize the pulse-width signal that the MCU controller of optical transceiver module inside produces, through bleeder circuit, low-pass filter circuit, coupling circuit, the biased electrical terminal of input Distributed Feedback Laser.Adjusted the frequency of the pulse-width signal of generation by the digital register adjusting MCU controller inside, adjustment current-limiting resistance adjusts the amplitude of modulation signal, thus inhibition is adjusted to optimum state.

Below in conjunction with Fig. 3, embodiment is described in detail.Long spacing module EML laser used, wherein the forward voltage of DFB is at below 1.6V, MCU pulse-width signal high level is out at 3.3V, R1 and R2 is utilized to do dividing potential drop, make the pulse-width modulation low frequency signal amplitude be added on DFB control at below 1.6V, signal amplitude V=3.3V*R2/ (R1+R2), C1 do a low-pass filtering, high fdrequency component on filtering pwm signal, reduces the impact on laser normal transmission light.Pulse-width signal is made to have enough driving forces through a follow circuit, because the characteristic impedance of EML laser is at 50 ohm, the resistance of adjustment current-limiting resistance R3 can adjust the drive current Is of pwm signal, the value of Is can be determined according to the bias current Ib of EML laser, the proportionality coefficient of dissimilar EML laser diode current is different, assuming that proportionality coefficient is K, Is=V/ (R3+50)=Ib*K, R3=(V-Ib*K*50)/(Ib*K), the frequency of pwm signal is adjusted by the digital register on MCU, frequency is adjusted between a few megahertz in a few KHz, the inhibition of SBS is made to reach best.

If Fig. 4 is the testing apparatus figure that SBS suppresses circuit, the size of adjustment drive current Is and the amplitude of pulse-width signal, the fiber reflection spectrum observed on spectrometer, the reflectance spectrum power reduction that SBS is produced is to desirable state.Be illustrated in figure 5 reverberation spectrogram when not having SBS suppression circuit, be illustrated in figure 6 the reverberation spectrogram after using SBS to suppress circuit, spectrogram after more not using SBS to suppress the spectrogram of circuit and use SBS to suppress circuit can be seen, utilize the power reduction of the reverberation that SBS produces after circuit of the present invention more than 40dB, can effectively suppress SBS effect, meet the requirement of ultra long haul transmission.

Claims

1. be with the optical transceiver module of digital adjustable SBS inhibit feature, be encapsulated as XFP form, inside modules comprises EML laser, laser emission control drive circuit, APD receiver, APD receives Drive and Control Circuit and MCU controller, EML laser is used for utilizing emitted light and exports, EML laser connects MCU controller by laser emission control drive circuit, APD receiver is for receiving light input, APD receiver receives Drive and Control Circuit by APD and connects MCU controller, it is characterized in that: in module, be integrated with SBS suppress circuit, SBS suppresses the input of circuit to connect described MCU controller, receive pulse-width signal, SBS suppresses the output of circuit to connect described EML laser, export broadening spectral line drive singal, the pulse-width signal utilizing MCU controller to produce, is modulated on the biasing circuit of EML laser, increases the breadth of spectrum line of the light wave that Distributed Feedback Laser exports in EML laser, thus improves the threshold values of optical transceiver module SBS.

2. the optical transceiver module of the digital adjustable SBS inhibit feature of band as claimed in claim 1, it is characterized in that, described SBS suppresses circuit to comprise: pulse-width signal contact resistance R1 one end that MCU controller exports, the resistance R1 other end is respectively through resistance R2 and electric capacity C1 ground connection, the in-phase input end of the resistance R1 other end also concatenation operation amplifier, the output of operational amplifier connects the inverting input of self and holds through resistance R3 to be connected EML laser optical emitting module LD+ with electric capacity C2.

3. the optical transceiver module of the digital adjustable SBS inhibit feature of band as claimed in claim 1, it is characterized in that, the frequency of the pulse-width signal of generation is adjusted by the digital register adjusting MCU controller inside, adjustment current-limiting resistance R3 adjusts the amplitude of pulse-width signal, thus inhibition is adjusted to optimum state.