WO2015192415A1

WO2015192415A1 - Method for multicasting 1 to 2 paths of signals among three paths of dpsk signals

Info

Publication number: WO2015192415A1
Application number: PCT/CN2014/082058
Authority: WO
Inventors: 王宏祥; 秦军; 杨玉倩; 刘川; 纪越峰
Original assignee: 北京邮电大学
Priority date: 2014-06-19
Filing date: 2014-07-11
Publication date: 2015-12-23
Also published as: CN104052550A

Abstract

The present invention relates to the technical field of all-optical information processing. Disclosed is a method for multicasting 1 to 2 paths of signals among three paths of DPSK signals. The method comprises: after three paths of DPSK signal light are generated by means of a modulator, eliminating the relevance between signals by using an optical delay line; and entering an SOA through a coupler in a coupling manner. An FWM effect is generated among the three paths of optical signals in an SOA, and then nine paths of idler-frequency light are generated; phase information of two paths of the newly generated idler-frequency light is the same as that carried by the three paths of originally input DPSK signal light, and then 1 to 2 paths of signals among the three paths of DPSK signals are multicast by filtering and receiving the light under the condition that no extra pump light is available. The method of the present invention is provided for the first time for multicasting 1 to 2 paths of signals among three paths of DPSK signals under the condition that no extra pump light is required.

Description

Method for simultaneously realizing three-way DPSK signal 1-2 signal multicast

Technical field

The invention relates to an optical network, in particular a gateway node, which utilizes a third-order nonlinear effect in a nonlinear device semiconductor optical amplifier (SOA)-four-wave mixing (FWM) to simultaneously achieve the same without requiring pump light. The method of three-way input DPSK signal for one-way to two-way (1-2) multicast belongs to the field of all-optical signal processing technology. Background technique

All-optical signal processing technology is regarded as a very promising technology in the future optical network. With the development of transmission technology in the communication field, broadband Internet has become popular, and the improvement of signal transmission rate and communication capacity has brought many benefits to people. For example, video conferencing, HDTV, distance education, etc., but also brought a lot of pressure on the network. First and foremost is the power consumption problem. In the wavelength division multiplexing system, multiple optical and electro-optical signal conversion circuits corresponding to the number of wavelengths are required. In addition, routing and switching within the electrical domain also have significant power consumption. The other aspect is the processing speed problem. The processing speed of the electric domain has become the bottleneck of the entire optical network communication, and the processing of the signal under the condition of all light can effectively alleviate the above problem. Therefore, all-optical signal processing technology has attracted more and more attention. As an important supporting technology for future optical networks, it has broad development prospects and important practical significance.

An important area of all-optical signal processing technology - all-optical signal multicast technology can effectively improve network efficiency and resource utilization by effectively multicasting signals at one wavelength to multiple wavelengths. Signal multicast technology plays an increasingly important role in the emergence of high-definition TV services and data migration in data centers.

Due to the importance of signal multicast technology, it has been widely and deeply studied in recent years. The main method adopted is to use different nonlinear effects of a certain number of pump light and signal light in various nonlinear devices. carry out. Non-linear devices involved include high nonlinear fiber (HNLF), semiconductor optical amplifier (SOA), quantum dot semiconductor optical amplifier (QD-SOA), photonic crystal fiber (PCF), silicon-based waveguide (Silicon Waveguide), silicon-based Nanowires and periodically poled lithium niobate waveguides (PPLN). The main non-linear effects used include cross-phase modulation (XPM), cross-gain modulation (XGM), four-wave mixing (FWM) effects, and various cascaded second-order nonlinear effects such as cascaded octave difference (cSHG/DFG) Effect, cascading and frequency difference frequency effect (cSFG/DFG). However, current signal multicast technologies are directed to multicasting of a single input channel signal, and no multicasting of multiple input channel signals has been involved. At the same time, the existing multicast scheme uses a certain amount of pump light, and there is overhead of pumping light. Moreover, the existing mechanisms generally have problems such as high signal input power, low conversion efficiency, and high system complexity.

As an important nonlinear device, SOA has the advantages of strong nonlinear effect, dynamic gain and large dynamic range, compact structure and easy integration. It has a special important position in all-optical signal processing. The SOA-based FWM effect is transparent to the bit rate and modulation format of the signal, enabling higher gain over a wide range of wavelengths, and various relaxations of SOA (carrier density pulsing CDP, carrier heating CH and The spectral burn hole SHB) has a short time. Multicasting multi-input channel signals using SOA as a nonlinear medium can provide additional advantages such as relatively high conversion efficiency and low input signal power. As people's requirements for communication capacity and quality continue to increase, the differential phase shift keying modulation format (DPSK) has become a research hotspot in optical fiber communication technology due to its good performance. The DPSK modulation method requires relatively low laser linewidth and uses a receiver that is simple in structure, based on interferometer demodulation and direct detection. The spectral width of the DPSK signal is between the non-return-to-zero code (NRZ) and the return-to-zero code (RZ). It is more spectrally efficient than the normal RZ code and can improve the dispersion tolerance, nonlinear tolerance and polarization mode dispersion tolerance. , increase the transmission distance. Compared to traditional On-Off Keying (OOK) modulation, DPSK signals can transmit longer distances and reduce optical power requirements. The research on multicast technology for DPSK signals will play an important role in the network, and the multicast technology for multiple input signals will further improve network efficiency and performance. Summary of the invention

The present invention provides a method for simultaneously implementing three-way DPSK signal 1-2 signal multicast. The technical solution is as follows:

A method for simultaneously implementing three-way DPSK signal 1-2 signal multicasting includes:

The three DPSK signal lights are generated by the modulator and injected into the SOA at the same time. The three light waves have a FWM effect in the SOA interaction, and a total of nine idler lights are generated. Due to the internal mechanism of the FWM, part of the newly generated idler light carries the same information as the input signal light. It is demonstrated that the multicast of the three signals can be completed simultaneously under the condition of three-way DPSK signal light input.

The technical solution provided by the present invention has the beneficial effects of: using all-optical mode for signal multicasting, which is not limited by the rate of the electrical device, has a relatively simple structure, is easy to operate, and is transparent to the signal modulation format. With SOA as the nonlinear medium, the FWM conversion efficiency is relatively high, and the input power requirement of the signal is low at the same time. No additional pumping sources are required throughout the multicast process, reducing system overhead. For the first time, the present invention is the first in the industry to simultaneously perform multi-channel (3-way) DPSK signals with one-way to two-way (1-2) signals without the participation of pump light. DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be briefly described in the following description of the embodiments of the present invention. It is obvious that the drawings in the following description are only some embodiments of the present invention. For the average technician, more drawings can be obtained from these drawings without any creative work.

1 is a flowchart of a method for simultaneously implementing three-way DPSK signal 1-2 signal multicast according to an embodiment of the present invention;

2 is a schematic diagram of a method for simultaneously implementing three-way DPSK signal 1-2 signal multicast according to an embodiment of the present invention;

Table 1 is a truth table of optical wave phases of a method for simultaneously implementing three-way DPSK signal 1-2 signal multicast according to an embodiment of the present invention. detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings in the embodiments. It is apparent that the described examples are only a part of the embodiments of the invention, rather than all of the embodiments. General techniques in the art based on embodiments in the present invention All other embodiments obtained by a person without creative efforts are within the scope of the present invention.

Referring to FIG. 1 , a flow chart of a method for simultaneously implementing three-way DPSK signal 1-2 signal multicasting in this embodiment includes:

S101: generating three DPSK signals to be multicast;

The DPSK signal for this method is multicast. The three-way optical carrier is generated by the light source and enters the modulator to generate three DPSK signals. A polarization controller is used to adjust the polarization state of the signal light. The second and third signal lights use optical delay lines (ODL) to remove the correlation between the signals. The resulting three DPSK signals are coupled through two 1 X 2 couplers.

S102: triggering a FWM process, generating a new idler light, and further implementing the multicast method as described in the present invention;

The three-way DPSK signal light has a FWM effect in the SOA. As shown in Figure 2, a new nine idler light will be generated. The three input DSPK signal lights are located at frequencies f ₂ and f _{3 respectively} , passing the FWM process in SOA at f ₁₁₃ , f ₁₂₃ , ₂₁₃ , f ₂₂₃ , f„ ₂ , f ₂₂₁ , f , f , f ₃₃₂ , f _A new signal light is generated at _331. Each of the multicast signals satisfies the original signal light in frequency: f _ab . = f _a +f _b -f ( a, b, c is selected from 1, 2, 3 The phase of the newly generated idler light and the phase of the original input 3 signal light satisfy the relationship shown in Table 1. Since the phase has a periodicity of 2pi, the idle frequency light at f ₂₂₁ , f ₃₃₁ The phase information carried is exactly the same as the information of the input signal light 1. The phase information carried by the idler light at f ₁₁₂ , f ₃₃₂ is exactly the same as the information of the input signal light 2. The idle frequency at f ₁₁₃ , f ₂₂₃ The phase information carried by the light is exactly the same as the information of the signal light 3. (The signal light at frequencies ₃ , ₂₁₃ , !^^, ^^^ does not remain exactly the same as the information of the original input signal light.) Based on the above The principle is to realize the multicasting of the signals of the three input DPSK signals from one to two (1-2) respectively.

S103: receiving a multicast DPSK signal;

The signal light newly generated in step S102 is filtered by the filter and then received into the receiver for reception, and the original signal is demodulated and recovered.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments are modified, or the technical features are equivalently replaced. The modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

Claim

1. A method for simultaneously realizing three-way DPSK signal 1-2 signal multicast, characterized in that: three-way DPSK signal light is simultaneously multicasted, and a four-wave mixing effect between three light waves is adopted.

2. The method according to claim 1, wherein: the wavelength conversion is completed while the signal is multicasted, and the signal multicast of 1-2 is simultaneously completed for the three DPSK signals.

3. The method according to claim 1, characterized in that: the simultaneous input of the three input DPSK signals can be completed without additional pump light input.