CN106199828B - Ultrafast microwave leads the full light trigger of Sagnac ring - Google Patents

Abstract

The present invention provides a kind of ultrafast microwaves to lead the full light trigger of Sagnac ring, including waveguide Sagnac ring, hollow-core photonic crystal fiber is respectively equipped on the waveguide Sagnac ring, doped optical fibre amplifier, polarization beam combiner, coupler and optical circulator, wherein, it is respectively the first optical circulator and the second optical circulator that the optical circulator, which has two, it is respectively the first coupler and the second coupler that the coupler, which has two, first optical circulator is connect with first coupler, second optical circulator is connect with second coupler, first coupler, second coupler is connect with the both ends of the hollow-core photonic crystal fiber respectively, it is respectively the first polarization beam combiner and the second polarization beam combiner that the polarization beam combiner, which has two,.The beneficial effects of the present invention are: it is small in size, it is easily integrated, transmission rate is high, and the bit error rate is small.

Description

Ultrafast microwave-guided Sagnac ring all-optical trigger

technical field

The invention relates to an optical trigger, in particular to an ultrafast microwave-guided Sagnac ring all-optical trigger.

Background technique

Optical flip-flop is an optical logic device with memory function. It is one of the basic technologies of digital optical signal processing and one of the key technologies of all-optical packet switching network. As the most basic all-optical signal processing device, all-optical flip-flops are used in It is used in data packet switching nodes, all-optical shift registers and all-optical bit-level data buffers.

At ECOC 2015, Huawei released the new technology achievements of "Minimal Networking", which aroused widespread concern in the industry. This technology realizes metro 100G transmission at low cost, and achieves a breakthrough in 80km transmission at a single-wavelength 112Gb/s rate. Therefore, the optical memory storage device, the core device of high-speed switching in the future optical network, is the basic element for realizing the application of ultra-high-speed optical fiber communication systems.

So far, many domestic and foreign scholars have conducted research on all-optical flip-flops and achieved some results. In 1995, H. Kawaguchi et al. proposed to use vertical cavity surface emitting laser (VCSEL) to realize the trigger, which is sensitive to the environment, the state retention of the trigger is not easy to control, and the cascadability is poor; Spain's F. Ramos et al. used a single MZI-SOA to realize the Mach-Zehnder interferometer (MZI-SOA) structure assisted by SOA. The structure of this flip-flop is simple, the response time is less than Easy to integrate and cascade; in 2006, scholars such as Yong Deok Jeong in South Korea proposed the use of two coupled Fabry-Perot (FP-LD) lasers to realize the optical trigger function. The fiber grating in this scheme is small and easy to integrate. , the state of the trigger is easy to maintain, and the cascading is good, but the state of the trigger is easily affected by temperature; the optical trigger based on the terahertz asymmetric optical demultiplexer (TOAD) uses an active device semiconductor optical amplifier to realize the optical pulse Due to the inconsistency of wavelength, the cascade of triggers is poor, the noise index is relatively high, and the bandwidth utilization rate is not good. Multimode interference bistable laser diodes (MMI-BLDs) It is not easy to trigger, and the mutual repulsion is not good; the two-dimensional photonic crystal all-optical trigger (2-D PhC) is small in size and easy to integrate, but it is difficult to precisely control the phase difference of the incident signal beam, requires high input power, and can consume a lot.

Although there are many kinds of flip-flops, there are some shortcomings that lead to low utilization value. In optical communication, all-optical signal processing involves signal multiplexing, switching, regeneration, synchronization, storage, calculation and other aspects. To operate in an optical network, an all-optical signal processing device must have the following characteristics:

(a) It can process high-speed signals and has a simple structure.

(b) The power consumption is small, which should be less than the energy consumption of electrical devices as much as possible.

(c) Ease of integration.

(d) The above-mentioned advantages can be exerted in the application field.

We have seen that all-optical signal processing technology has made great progress. Nevertheless, these devices still have a certain gap with the above four requirements. In the field of optical communication, all-optical signal processing technology should completely replace electrical signal processing devices. There is still a long way to go.

SUMMARY OF THE INVENTION

In order to solve the problems in the prior art, the present invention provides an ultrafast microwave-guided Sagnac ring all-optical trigger.

The present invention provides an ultrafast microwave-guided Sagnac ring all-optical trigger, comprising a waveguide Sagnac ring on which a hollow-core photonic crystal fiber, a doped fiber amplifier, a polarization beam combiner, a coupler and an optical fiber are respectively provided. A circulator, wherein, the optical circulator has two respectively a first optical circulator and a second optical circulator, the coupler has two respectively a first coupler and a second coupler, the first optical circulator The optical circulator is connected to the first coupler, the second optical circulator is connected to the second coupler, and the first coupler and the second coupler are respectively connected to two sides of the hollow-core photonic crystal fiber. The two polarizing beam combiners are respectively a first polarizing beam combiner and a second polarizing beam combiner, and the first polarizing beam combiner and the second polarizing beam combiner are respectively connected with the hollow photon The two ends of the crystal fiber are connected. The first optical pulse and the second optical pulse are input signals respectively. The first optical pulse is input from the input port IP1 and is divided into clockwise optical pulses through the first coupler, and the second optical pulse is divided into clockwise optical pulses. The input from the input port IP2 is divided into counterclockwise optical pulses through the second coupler. The first beam of control signal optical pulses passes from the control port CP1 through the first polarization beam combiner to one end of the hollow-core photonic crystal fiber, and the second beam of control signal optical pulses. The optical pulse passes through the second polarization beam combiner from the control port CP2 to the other end of the hollow-core photonic crystal fiber, the first beam of control signal optical pulse and the clockwise optical pulse undergo cross-phase modulation and then loop back to the first coupler, and After being pulse-shaped from the first optical circulator to the output port OP1, the second control signal optical pulse and the counterclockwise optical pulse are cross-phase modulated and then looped back to the second coupler, and pulse-shaped from the second optical circulator to the output port OP1. Output port OP2.

As a further improvement of the present invention, a first polarization rotator is connected to the rear end of the control pulse of the first polarization beam combiner. The cross-polarized first control signal.

As a further improvement of the present invention, a second polarization rotator is connected to the rear end of the control pulse of the second polarization beam combiner. A second control signal that is cross-polarized.

As a further improvement of the present invention, the input end of the first polarization rotator is connected with a first doped fiber amplifier, the input end of the second polarization rotator is connected with a second doped fiber amplifier, and the control port CP1 It is connected with the first doped fiber amplifier, and the control port CP2 is connected with the second doped fiber amplifier.

As a further improvement of the present invention, the hollow-core photonic crystal fiber is an optical fiber ring.

As a further improvement of the present invention, both ends of the hollow-core photonic crystal fiber are respectively connected with a first polarization beam splitter and a second polarization beam splitter.

As a further improvement of the present invention, the waveguide Sagnac ring has a three-layer structure, including a 235-nanometer-thick monocrystalline silicon upper layer, a 3-micron-thick silicon dioxide buffer layer in the middle layer, and a 525-micron-thick silicon substrate in the lower layer .

The beneficial effects of the invention are: small size, easy integration, high transmission rate, low bit error rate, and suitable for large-scale integrated optical circuits.

Description of drawings

FIG. 1 is a schematic diagram of an ultrafast microwave-guided Sagnac ring all-optical trigger of the present invention.

2 is a layered schematic diagram of a waveguide Sagnac ring of an ultrafast microwave-guided Sagnac ring all-optical trigger of the present invention.

Figure 3 is a modular representation of a waveguide Sagnac switch.

FIG. 4 is a schematic diagram of a first embodiment of a D flip-flop.

FIG. 5 is a schematic diagram of the second embodiment of the D flip-flop.

Figure 6 is a schematic diagram of an R-S flip-flop.

Figure 7 is a schematic diagram of a J-K flip-flop.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1, an ultrafast microwave-guided Sagnac ring all-optical trigger includes a waveguide Sagnac ring on which a hollow-core photonic crystal fiber 3 (HC-PCF for short) and a doped fiber amplifier are respectively provided , a polarization beam combiner (abbreviated as PBC), a coupler (abbreviated as 3dB C) and an optical circulator (abbreviated as OC), wherein the optical circulator has two first optical circulator 11 and second optical circulator 12 respectively , the coupler has two first coupler 21 and second coupler 22, the first optical circulator 11 is connected with the first coupler 21, and the second optical circulator 12 is connected with the The second coupler 22 is connected, the first coupler 21 and the second coupler 22 are respectively connected with both ends of the hollow-core photonic crystal fiber 3, and the polarization beam combiner has two first polarization A beam combiner 31 and a second polarization beam combiner 32 , the first polarization beam combiner 31 and the second polarization beam combiner 32 are respectively connected to both ends of the hollow-core photonic crystal fiber 3 .

As shown in FIG. 1 , the rear end of the control pulse of the first polarization beam combiner 41 is connected with a first polarization rotator 51 (PR for short), and the first beam of control signal light pulses passes through the first polarization rotator 51 to obtain a The optical pulses are the first control signal with the same wavelength and orthogonal polarization.

As shown in FIG. 1 , the rear end of the control pulse of the second polarization beam combiner 42 is connected with a second polarization rotator 52 (PR for short), and the second beam of control signal light pulses passes through the second polarization rotator 52 to obtain a A second control signal of the same wavelength of the optical pulses but orthogonally polarized.

As shown in FIG. 1 , the input end of the first polarization rotator 51 is connected with a first doped fiber amplifier 71 (EDFA for short), and the input end of the second polarization rotator 52 is connected with a second doped fiber amplifier 71 72 (EDFA for short), the control port CP1 is connected to the first doped fiber amplifier 71 , and the control port CP2 is connected to the second doped fiber amplifier 72 .

As shown in FIG. 1 , the hollow-core photonic crystal fiber 3 is a fiber ring.

As shown in FIG. 1 , two ends of the hollow-core photonic crystal fiber 3 are respectively connected with a first polarization beam splitter 61 (abbreviated as PBS) and a second polarization beam splitter 62 (abbreviated as PBS).

As shown in Figure 1, the first light pulse and the second light pulse are input signals respectively. The first light pulse is input from the input port IP1 and is divided into clockwise light pulses (CW) through the first coupler 21. The light pulses are input from the input port IP2 and pass through the second coupler 22 to be divided into counterclockwise light pulses (CCW). 51. From the first polarization beam combiner 41 to one end of the hollow-core photonic crystal fiber 3, the second control signal light pulse passes through the second doped fiber amplifier 72, the second polarization rotator 52, the second doped fiber amplifier 72, the second polarization The polarization beam combiner 42 is connected to the other end of the hollow-core photonic crystal fiber 3, and the first control signal light pulse and the clockwise light pulse (CW) undergo cross-phase modulation (XPM, Cross-phase Modulation) and then loop back to the first coupling In the coupler 21, and through pulse shaping from the first optical circulator 11 to the output port OP1, the second beam of control signal optical pulses and counterclockwise optical pulses (CCW) are cross-phase modulated and then looped back to the second coupler 22, and It is pulse shaped from the second optical circulator 12 to the output port OP2.

As shown in FIG. 2 , the waveguide Sagnac ring has a three-layer structure, including a 235-nanometer-thick monocrystalline silicon upper layer, a 3-micron-thick silicon dioxide buffer layer in the middle layer, and a 525-micron-thick silicon substrate in the lower layer. The coupler, polarization controller and photonic crystal fiber are etched on it, and then devices such as optical circulator and optical amplifier are externally connected. Using HC-PCF as the ring, the light energy is concentrated in the center of the fiber, the air hole diameter d is 110nm, the hole spacing is 200nm, the air filling rate d/=0.55>0.406, the light is confined to the central hollow core, and some studies have shown that , this PCF can transmit more than 99% of the light energy, and the spatial light attenuation is extremely low, and the fiber attenuation is only 1/2 to 1/4 of the standard fiber.

According to the principle and characteristics of the waveguide Sagnac switch, D-type, R-S-type, J-K-type and T-type flip-flops are designed. Table 1 lists the corresponding characteristic table, and the modular representation is shown in Figure 3 to Figure 7.

Table 1 Basic binary flip-flop characteristic table

In Fig. 4, IP1=1, CP1=1, OP2=Qn+1=1, IP1=0, CP1=1, OP2=Qn+1=0, which is the "hold" operation of the D-type flip-flop. In Figure 5, IP1=IP2=0, CP1=CP2=1, Qn+1=0, this is the "0" operation of the R-S flip-flop; IP1=1, IP2=0, CP1=1, CP2=0 , Qn+1=1, this is the “1” operation of the R-S flip-flop; CP1=1, if the previous state Qn=1, Qn+1=1, if the previous state Qn=0, Qn+1 =0, this is the "hold" operation of the R-S type flip-flop, S=1, R=1 is prohibited, all input conditions of the R-S type flip-flop can use the characteristic equation Qn+1=S+`RQn (constraint condition SR =0) indicates. In Figure 6, J and K are respectively input to two logic AND gates composed of polarization switches S1 and S2, and the two-way delay line feedback phase-AND operation is output to S and R for input. The J-K type flip-flop solves the problem. The situation of "S=1, R=1" is prohibited in the R-S type flip-flop; in Figure 7, when T=0, that is, J=K=0, it can be known from the characteristics of the J-K type flip-flop that Qn+1=Qn, this It is the "hold" function of the T-type flip-flop. When T=1, that is, J=K=1, Qn+1=this is the "flip" function of the T-type flip-flop.

The ultrafast microwave-guided Sagnac ring all-optical trigger provided by the invention reduces the disadvantages of high noise and unstable system state caused by using SOA, and adopts a highly nonlinear hollow-core photonic crystal fiber (HC-PCF) to make the The system has smaller input power and lower power consumption than ever before, and the transmission rate is 100Gb/s. The all-optical trigger has stable performance, low power consumption, transmission rate up to 100Gb/s, input power of 0.05mw, response time in the ps level, small size and easy integration, and has great potential in large-scale integration of cascaded optical circuits It is of great significance to promote the development of all-optical signal processing technology and all-optical packet switching, all-optical routing, all-optical computing and other fields.

The ultrafast microwave-guided Sagnac ring all-optical trigger provided by the present invention has the following advantages:

1. A new type of waveguide Sagnac structure using silicon material, designed D, R-S, J-K and T-type all-optical flip-flops, small size, easy to integrate, transmission rate 100Gb/s, low bit error rate, suitable for large-scale integrated optical circuits.

2. Reduce the disadvantages of using SOA, such as large noise and unstable system state.

3. The use of HC-PCF makes the input power of the system small, the power consumption is low, and the system is stable.

4. The waveguide Sagnac ring all-optical trigger is small in size, low in power (uw), low in loss, fast in response time (ps), high in transmission rate (100Gb/s), low in bit error rate (10-9), There is great potential in the scale integration of cascaded optical circuits.

The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deductions or substitutions can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (5)

1. an ultrafast microwave-guided Sagnac ring all-optical trigger, is characterized in that: comprise a waveguide Sagnac ring, and the described waveguide Sagnac ring is respectively provided with a hollow-core photonic crystal fiber, a polarization beam combiner, a coupler and an optical circulator, Wherein, there are two optical circulators, respectively a first optical circulator and a second optical circulator, and two of the couplers are a first coupler and a second coupler, respectively, the first optical circulator is connected to the first coupler, the second optical circulator is connected to the second coupler, the first coupler and the second coupler are respectively connected to both ends of the hollow-core photonic crystal fiber, There are two polarization beam combiners, respectively a first polarization beam combiner and a second polarization beam combiner, and the first polarization beam combiner and the second polarization beam combiner are respectively connected with the hollow core photonic crystal fiber. The two ends are connected. The first light pulse and the second light pulse are input signals respectively. The first light pulse is input from the input port IP1 and is divided into clockwise light pulses through the first coupler, and the second light pulse is sent from the input port. The IP2 input is divided into counterclockwise light pulses through the second coupler. The first control signal light pulse passes from the control port CP1 through the first polarization beam combiner to one end of the hollow-core photonic crystal fiber, and the second control signal light pulse from the control port CP1. The control port CP2 passes through the second polarization beam combiner to the other end of the hollow-core photonic crystal fiber, and the first control signal light pulse and the clockwise light pulse undergo cross-phase modulation and then loop back to the first coupler, and from the first The optical circulator is pulse-shaped to the output port OP1, the second control signal optical pulse and the counterclockwise optical pulse are cross-phase modulated and then looped back to the second coupler, and pulse-shaped from the second optical circulator to the output port OP2 ; The input end of the first polarization beam combiner is connected with a first polarization rotator, and the first control signal light pulse passes through the first polarization rotator to obtain a first control signal with the same wavelength and orthogonal polarization as the first light pulse; The input end of the second polarization beam combiner is connected with a second polarization rotator, and the second control signal light pulse passes through the second polarization rotator to obtain a second control signal with the same wavelength and orthogonal polarization as the second light pulse; The first bundle of control signal light pulses passes through the first polarization rotator and the first polarization beam combiner from the control port CP1 to one end of the hollow-core photonic crystal fiber, and the second bundle of control signal light pulses passes from the control port CP2 to the second one. A polarization rotator, a second polarization beam combiner into the other end of the hollow-core photonic crystal fiber. 2. The ultrafast microwave-guided Sagnac ring all-optical trigger according to claim 1, wherein the input end of the first polarization rotator is connected with a first doped fiber amplifier, and the second polarization rotator is connected with a first doped fiber amplifier. A second doped fiber amplifier is connected to its input end, the control port CP1 is connected to the first doped fiber amplifier, and the control port CP2 is connected to the second doped fiber amplifier. 3 . The ultrafast microwave-guided Sagnac ring all-optical trigger according to claim 1 , wherein the hollow-core photonic crystal fiber is a fiber ring. 4 . 4. The ultrafast microwave-guided Sagnac ring all-optical trigger according to claim 1, wherein both ends of the hollow-core photonic crystal fiber are respectively connected with a first polarization beam splitter and a second polarization beam splitter . 5 . The ultrafast microwave-guided Sagnac ring all-optical trigger according to claim 1 , wherein the waveguide Sagnac ring has a three-layer structure, comprising 235 nm thick monocrystalline silicon in the upper layer and 3 microns in the middle layer. 6 . Thick silicon dioxide buffer layer and underlying 525 micron thick silicon substrate.