WO2008125033A1

WO2008125033A1 - A pluggable optical module and an electronic/ optical signal conversion apparatus

Info

Publication number: WO2008125033A1
Application number: PCT/CN2008/070398
Authority: WO
Inventors: Peng Huang; Zhipeng Zhao
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-04-13
Filing date: 2008-03-04
Publication date: 2008-10-23
Also published as: CN201039188Y

Abstract

A pluggable optical module and an electronic/ optical conversion signal apparatus, relate to a signal conversion apparatus in fiber communication system. The pluggable optical module comprises: a laser, a driving circuit, a coupling circuit and a scrambling circuit; one end of the coupling circuit is connected to the scrambling circuit, and the other end is connected to the input end of the laser. The optical/ electronic signal conversion apparatus comprises: a pluggable optical module and a coupling circuit and a scrambling circuit that are both situated in the outside of the pluggable optical module. The pulggable optical module comprises a laser and a driving circuit; one end of the coupling circuit is connected to the scrambling circuit and the other end is connected to the pluggable optical module.

Description

Pluggable optical module and electric/optical signal conversion device

This application claims the priority of the Chinese patent application filed on April 13, 2007, the Chinese Patent Office, the application number is 200720143831.X, and the utility model name is "pluggable optical module and electric/optical signal conversion device". The entire contents are incorporated herein by reference.

5 Technical fields

The utility model relates to a signal conversion device in an optical fiber communication system, in particular to a pluggable optical module and an electric/optical signal conversion device.

Background technique

The continuous development of communication technology has put forward high density and low power consumption requirements for communication systems. A new type 0 optical module such as SFP (Small Form-factor Pluggable), XFP (10 Gigabit Small) Form-factor Pluggable, 10G miniaturized pluggable optical modules), SFP+, XFP-E, QSFP (Qua (4-channel) Small Form-factor Pluggable), X40, XENPAK and other pluggable optical modules came into being. These pluggable optical modules have the advantages of miniaturization, low power consumption, pluggable, etc., and can provide an I2C (Inter- Integrated Circuit) bus interface.

_5 is the management control interface, etc. The I2C bus is a two-wire synchronous serial data transmission bus defined by Philips to connect the micro control unit and its peripherals.

In fiber-optic communication, when the span loss is large, an optical amplifier must be used to increase the incident power of the fiber to meet the link loss budget. When the incident power of the fiber exceeds a certain threshold, the output power of the fiber does not increase with the increase of the incident power, but decreases. This is called the stimulated Buri.

»0 SBS, Stimulated Brillouin Scattering effect. Due to the stimulated Brillouin backscattering effect (in general, stimulated Brillouin scattering occurs only in the back direction), the forward transmitted optical signal is converted to the back Brillouin scattered light, causing the forward direction The transmitted optical power fluctuates, thus seriously degrading the transmission performance of the system. The threshold mentioned above is the threshold of SBS, which is related to the characteristics of the fiber and the laser. The wider the output spectrum of the laser, the larger the SBS.

»5 When the laser is pulse-modulated, if the injected current changes, the carrier concentration in the active region will change, which will cause the refractive index to change, causing the resonant frequency to change, eventually causing the laser. The spectrum of the emitted photons is broadened. It is proved by theory and experiment that by appropriately broadening the spectrum of the outgoing light of the optical module laser, the threshold of SBS can be significantly improved, thereby reducing the influence of SBS on the system under high power input. Therefore, it is necessary to increase the SBS threshold. For improving the SBS threshold, the commonly used method is: to provide a low-frequency perturbation signal to the optical module without affecting the system performance, increase the spectral width of the laser, that is, the effective spectral width of the optical carrier, and reduce the average power density. Thereby increasing the threshold of SBS.

For a normal optical module, since it has a disturbance signal input port reserved on the pin definition, for this type of optical module, the disturbance signal can be generated by an external disturbance circuit and passed through the reserved disturbance signal. The input port implements scrambling on the optical module.

However, for a pluggable optical module, since the pluggable optical module itself does not define a scrambling function, and the pin definition does not have an input for the disturbance signal, this limits the pluggable light. The application of the module in the case of long distance and high incident optical power.

0 Utility model content

The utility model provides a pluggable optical module and an electric/optical signal conversion device which can be applied in high incident power and long distance transmission.

The pluggable optical module of the utility model uses the following technical solutions:

a pluggable optical module, comprising a laser, a driving circuit connected to the input end of the laser, and further comprising: a coupling circuit and a disturbance circuit, wherein one end of the coupling circuit is connected to the disturbance circuit, and the other end is The input of the laser is connected;

The disturbance current generated by the disturbance circuit is attenuated by the coupling circuit and output to the input end of the laser; meanwhile, the drive current generated by the drive circuit is output to the input end of the laser; The input current is converted.

»0 The utility model of the utility model relates to the following technical solutions:

An electrical/optical signal conversion device includes: a pluggable optical module and a coupling circuit and a disturbance circuit disposed outside the pluggable optical module; the pluggable optical module includes a laser, and an input end of the laser a connected driving circuit; one end of the coupling circuit is connected to the disturbance circuit, and the other end is connected to the pluggable optical module;

The disturbance current generated by the disturbance circuit is attenuated by the coupling circuit, and is output to the input end of the laser through the pin of the pluggable optical module; the driving current generated by the driving circuit is output to the An input of the laser; the laser converts the input current into an optical signal.

The utility model combines the pluggable optical module with the disturbance function, and the disturbance current generated by the disturbance circuit is attenuated by the coupling circuit, and is output to the laser bias together with the driving current generated by the driving circuit. The pin is placed, and the input current signal is electrically/light converted by the laser. By applying the perturbation current on the laser driving current, the bias point of the laser is weakly modulated, thereby increasing the spectral width of the laser, increasing the threshold of the SBS, improving the transmission performance of the pluggable optical module, and extending the pluggable The transmission distance of the optical module enables the pluggable optical module with the disturbance function to be applied in high incident power and long distance transmission.

In addition, the electric/optical signal conversion device of the present invention can also provide a disturbing current through the externally disturbing circuit and the coupling circuit of the pluggable optical module through the pluggable optical module without the disturbance function. Input into the pluggable optical module; the disturbance current is output to the bias pin of the laser together with the drive current generated by the drive circuit. By applying the perturbation current on the laser drive current, the bias point of the laser is weakly modulated, thereby increasing the spectral width of the laser and increasing the threshold of the SBS.

Thus, the pluggable optical module without the perturbation function can be applied in high incident power, long-distance transmission.

DRAWINGS

1 is a schematic diagram of a pluggable optical module according to an embodiment of the present invention;

2 is an application schematic diagram of a coupling circuit of the embodiment of the present invention when a resistor and a capacitor are connected in series to form a _5;

3 is another application schematic diagram of the coupling circuit of the embodiment of the present invention when a resistor and a capacitor are connected in series;

4 is a schematic diagram of application of a disturbance circuit according to an embodiment of the present invention;

Figure 5 is a schematic diagram of the utility model when the I2C bus is used for control;

»0 Figure 6 is a schematic diagram of the electric/optical signal conversion device of the present invention.

detailed description

In order to make the advantages of the technical solutions of the present invention more clear, the pluggable optical module of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1, the pluggable optical module of the present invention comprises: a laser 10, a driving circuit 11 connected to the »5 input end of the laser 10, and further comprising: a coupling circuit 12 and a disturbance circuit 13, one end of the coupling circuit 12 and The disturbance circuit 13 is connected, and the other end is connected to the input end of the laser 10; the disturbance current generated by the disturbance circuit 13 is attenuated by the coupling circuit 12, and is output to the input end of the laser 10 together with the drive current generated by the drive circuit 11, that is, On the biasing pin of the laser 10, the input current is electrically/light converted by the laser 10. Driving electricity by laser 10 loaded in the pluggable optical module The perturbation current on the stream weakly modulates the bias point of the laser 10, changes the carrier concentration inside the laser 10, thereby increasing the spectral width of the laser 10, increasing the threshold of the SBS, and improving the transmission performance of the optical module. Make it suitable for long distance, high incident power.

For the coupling circuit 12, the implementation form of the present invention is not limited. One form of implementation 5 can be a series of resistor and capacitor coupling resistors. The resistor-capacitor coupling resistor circuit forms an attenuation network and prevents the drive current from interfering with the disturbance current. As shown in FIG. 2, the resistor and the capacitor may be one or more, and the resistor may be an adjustable resistor or an unregulated resistor. When the resistor is an adjustable resistor, the amplitude of the disturbance current can be adjusted by adjusting the resistance of the adjustable resistor during the setting of the pluggable optical module. The 0 input of the adjustable resistor is connected to the disturbance circuit, the output is connected to one end of the capacitor, and the other end of the capacitor is connected to the bias pin of the laser. In addition, as shown in FIG. 3, the attenuation network may be in the form of: one end of the capacitor is connected to the disturbance circuit, the other end of the capacitor is connected to one end of the adjustable resistor, and the other end of the adjustable resistor is connected to the bias of the laser. Pin.

The disturbance current signal generated by the disturbance circuit passes through the attenuation network and becomes a disturbance current signal with a suitable amplitude _5 and frequency, which is input to the biasing pin of the laser together with the driving current generated by the driving circuit, so that the threshold value of the SBS The optimal value is reached. Therefore, the pluggable optical module with the coupling circuit, that is, the attenuation network, can better control the disturbance current input to the bias pin of the laser, thereby better adjusting the spectral width of the laser and improving the width of the SBS. value.

The implementation form of the disturbance circuit is also not limited in the present invention. As shown in FIG. 4, a real-time form of the disturbance circuit includes a clock generation circuit 41, and a digital frequency division circuit 42 connected to the output end of the clock generation circuit 41. The output terminal and the coupling circuit of the digital frequency division circuit 42 are shown. 12 connections. Then, the digital frequency dividing circuit 42 divides the clock signal of the clock generating circuit 41 to generate a disturbance current. The disturbance current is output to the biasing pin of the laser, together with the drive current generated by the drive circuit, via the coupling circuit 12.

In the present invention, the clock generation circuit 41 can be implemented by using a clock source of the pluggable optical module itself, and the digital frequency dividing circuit 42 can be a digital frequency divider or an FPGA (Field Programmable Gate Array). ) to realise.

In addition, the disturbance circuit can also be implemented by software. For example, a program can be programmed to make a certain frequency and amplitude disturbance of an I/O port output of a control unit inside the pluggable optical module. Current. The disturbance current is output to the bias pin of the laser, together with the drive current generated by the drive circuit, via the coupling circuit.

In addition, since the characteristics of the lasers of different manufacturers are different, the frequency and amplitude of the corresponding optimal disturbance current are also different. When producing optical modules, lasers can be used according to different pluggable optical modules.

The SBS threshold of the device calculates the optimal amplitude value and frequency value of the disturbance current, which is stored in the register unit inside the pluggable optical module. Therefore, when the pluggable optical module is working, the optical module can be inserted and removed. The control unit can call the optimum amplitude value and the frequency value to control the disturbance circuit.

As shown in FIG. 5, the present invention enables the disturbance circuit to be controlled by the I2C bus 14. The pluggable optical module is inserted on the board. The control unit is installed on the board. Therefore, the CPU

The enable control signal sent by the control unit such as 0 is sent to the control unit inside the pluggable module through the I2C bus 14, and the control unit inside the pluggable optical module enables the disturbance circuit 13 according to the enable control signal. control.

In addition, the utility model can also realize the adjustment of the frequency and amplitude of the disturbance signal through the I2C bus. When the user uses the pluggable optical module of the present invention, the user can set the amplitude and frequency value of the disturbance current through the _ 5 CPU set on the board, and send it to the pluggable optical module by the CPU through the I2C bus. An internal control unit; the control unit controls the disturbance circuit to output an optimum disturbance current. After the I2C bus is used to adjust the frequency and amplitude of the disturbance signal, the SBS threshold can be better adjusted to achieve the optimal value and improve the transmission performance of the optical module.

In some special cases, to apply a perturbation function to a pluggable optical module that does not have a perturbation function

»0 Yes, for pluggable optical modules such as SFP, because the 6 (mode definition 0), 7 (rate selection) pins are usually not used, they can be used to input the additional disturbance signal.

As shown in FIG. 6, the electrical/optical signal conversion device 61 of the present invention includes: a miniaturized pluggable optical module 60 and a coupling circuit 12 and a disturbance circuit 13 disposed outside the miniaturized pluggable optical module 60; The pluggable optical module 60 includes a laser 10 and a drive coupled to the input of the laser 10.

»5 moving circuit 11; one end of the coupling circuit 12 is connected to the disturbance circuit 13, and the other end is connected to the 6 or 7 pins of the miniaturized pluggable optical module 60. The disturbance current generated by the disturbance circuit 13 is attenuated by the coupling circuit 12, and is input to the miniaturized pluggable optical module 60 through the 6 or 7 pins of the miniaturized pluggable optical module 60, and the driving current generated by the driving circuit 11 Together, output to the input of the laser 10, which in turn electrically/inverts the input current. The disturbance circuit 13 includes a clock generation circuit 41 and a digital frequency division circuit 42 connected to the output terminal of the clock generation circuit 41. The output terminal of the digital frequency division circuit 42 is connected to the 6 or 7 tubes of the miniaturized pluggable optical module 60. On the feet.

The digital frequency dividing circuit 42 divides the clock signal of the clock generating circuit 41 to generate a disturbance current.

5 The digital frequency dividing circuit 42 is a digital frequency divider or an FPGA.

In summary, the utility model combines the pluggable optical module with the disturbance function, and the disturbance current generated by the disturbance circuit is output to the biasing pin of the laser together with the driving current generated by the driving circuit through the coupling circuit; By applying the perturbation current on the laser drive current, the bias point of the laser is weakly modulated, thereby increasing the spectral width of the laser, increasing the threshold of the SBS, improving the transmission _ 0 performance of the optical module, and making the disturbance function The pluggable optical module can be applied in high incident power and long-distance transmission, and the market is more competitive.

In addition, since the present invention utilizes the I2C bus to enable the disturbance circuit and adjust the amplitude and frequency of the disturbance signal, the pluggable optical module can be applied to different lasers. After the I2C bus is used to adjust the frequency and amplitude of the disturbance signal, the SBS wide value can be improved to achieve the optimal value and improve the transmission performance of the optical module.

At the same time, the utility model can realize the scrambling function of the laser by utilizing the resources of the pluggable optical module itself, and therefore, the utility model can reduce the production cost.

In addition, the electric/optical signal conversion device of the present invention applies a disturbance function to the pluggable optical module without the disturbance function through the external disturbance circuit and the coupling circuit, so that the application of the pluggable 0/0 light extraction module without the disturbance function is applied. The range is wider and can be applied in high incident power and long distance transmission.

Of course, there may be other various embodiments of the present invention, and those skilled in the art can make various corresponding changes and modifications according to the present invention without departing from the spirit and scope of the present invention. Corresponding changes and modifications are intended to be included within the scope of the appended claims.

Claims

Rights request

A pluggable optical module, comprising a laser, and a driving circuit connected to an input end of the laser, further comprising: a coupling circuit and a disturbance circuit, wherein one end of the coupling circuit is connected to the disturbance circuit The other end is connected to the input end of the laser;

5, the disturbance current generated by the disturbance circuit is attenuated by the coupling circuit, and output to the input end of the laser; meanwhile, the driving current generated by the driving circuit is output to the input end of the laser; Convert the input current into an optical signal.

2. The pluggable optical module according to claim 1, wherein: the coupling circuit is a series circuit composed of a resistor and a capacitor.

0. The pluggable optical module according to claim 1, wherein: the disturbance circuit comprises a clock generation circuit, and a digital frequency division circuit connected to an output end of the clock generation circuit; An output of the frequency circuit is coupled to the coupling circuit;

The digital frequency dividing circuit divides a clock signal of the clock generating circuit to generate a disturbance current.

The pluggable optical module of claim 3, wherein: the digital frequency dividing circuit is a digital frequency divider or a field programmable gate array.

5. The pluggable optical module according to claim 4, wherein: the input end of the clock generating circuit is connected to the I2C bus.

The electrical/optical signal conversion device of claim 5, wherein: the pluggable »0 optical module further comprises:

a registering unit for storing an optimal amplitude value and a frequency value of the disturbance current according to the stimulated Brillouin scattering SBS threshold of the laser;

And a control unit, configured to call an optimal amplitude value and a frequency value in the register unit, and control the disturbance circuit through the I2C bus.

»5

The pluggable optical module according to claim 6, wherein: the control unit enables the disturbance circuit by the I2C bus, or the frequency of the disturbance current generated by the disturbance circuit Adjust with the amplitude.

An electrical/optical signal conversion device, comprising: a pluggable optical module; and a coupling circuit and a disturbance circuit disposed outside the pluggable optical module; the pluggable optical module includes a laser, And a driving circuit connected to the input end of the laser; one end of the coupling circuit is connected to the disturbance circuit, and the other end is connected to the pluggable optical module;

The disturbance current generated by the disturbance circuit is attenuated by the coupling circuit, and is output to the input end of the laser through the pin of the pluggable optical module; the driving current generated by the driving circuit is output to the laser Input; the laser converts the input current into an optical signal.

9. The electric/optical signal conversion apparatus according to claim 8, wherein: the other end of the coupling circuit is connected to a pin of the pluggable optical module.

The electrical/optical signal conversion device according to claim 8, wherein: the pluggable optical module is a miniaturized pluggable optical module, and the pin of the pluggable optical module is miniaturized. Plug and unplug

The mode of the 0 module defines the pin or rate select pin.

11. The electric/optical signal conversion apparatus according to claim 10, wherein: said disturbance circuit comprises a clock generation circuit, and a digital frequency division circuit connected to an output end of said clock generation circuit; said digital division An output end of the frequency circuit is connected to a mode definition pin or a rate selection pin of the miniaturized pluggable optical module;

_5 The digital frequency dividing circuit divides a clock signal of the clock generating circuit to generate a disturbance current.

12. The electrical/optical signal conversion apparatus according to claim 11, wherein: said digital frequency dividing circuit is a digital frequency divider or a field programmable gate array.

The electric/optical signal conversion device according to any one of claims 8 to 12, wherein: the 0: the pluggable optical module further comprises:

a registering unit for storing an optimal amplitude value and a frequency value of the disturbance current according to the SBS threshold of the laser;

And a control unit, configured to call an optimal amplitude value and a frequency value in the register unit, and control the disturbance circuit.