Optical circulator and optical device

Abstract

The application provides an optical circulator and an optical device, comprising: a plurality of ports, a plurality of optical splitters and at least one pump light coupler, the output ends of the optical splitters of each port are connected in sequence; after incident light enters a target port, the incident light is divided into clockwise signals and counterclockwise signals by the optical splitter of the target port; the pump light coupler outputs pump light, the pump light is transmitted clockwise or counterclockwise in the optical circulator; the clockwise transmitted pump light and the clockwise signals generate Brillouin effect, and the clockwise signals are amplified; the clockwise signals are output from the next port of the target port after passing through the optical splitter of the next port of the target port; the counterclockwise transmitted pump light and the counterclockwise signals generate Brillouin effect, and the counterclockwise signals are amplified; the counterclockwise signals are output from the previous port of the target port after passing through the optical splitter of the previous port of the target port. The application can be realized by full light, and the dependence on additional components is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical technology, and in particular to an optical circulator and an optical device. BACKGROUND

[0002] An optical circulator is a multi-port optical device with non-reciprocity, which has a wide range of applications in fiber lasers, bidirectional pumping systems, dispersion compensation devices, and some advanced optical communication systems. In recent years, with the continuous progress of manufacturing technology, integrated photonic chips have shown great potential in optical communication, optical computing, and optical sensing. However, it is still a problem to be solved to realize a high-performance optical circulator in an integrated photonic chip.

[0003] The existing optical circulator has the following defects:

[0004] 1. The existing optical circulator can use a magneto-optic effect scheme, which requires an external magnetic field and relies on additional components.

[0005] 2. The number of ports of the existing optical circulator is difficult to expand, and it is difficult to meet the needs of more ports.

[0006] 3. The magneto-optic effect scheme has wafer bonding lattice mismatch, and the deposition material process is also very complex, requiring additional other materials and higher process difficulty.

[0007] 4. The existing optical circulator is difficult to dynamically realize the change of the circulator direction.

[0008] 5. The existing optical circulator is difficult to realize the function of optical circulator + optical amplifier.

[0009] 6. The existing optical circulator can use a spatial light scheme, which has a large size and is difficult to integrate other devices on the same chip, making it difficult to form a more complex optical system.

[0010] 7. The spatial light scheme requires strict alignment of the optical path, and has high requirements for the manufacturing process.

[0011] 8. The existing optical circulator can use a magneto-optic + MZI (Mach-Zehnder interferometer) scheme, which has poor stability. SUMMARY

[0012] Therefore, the present application aims to provide an optical circulator and optical device, all-optical implementation, reduced dependence on additional components; the number of ports is easy to expand, and the demand for more ports is easier to achieve; no additional materials are required, reducing process requirements; dynamically changing the direction of the circulator; capable of realizing the gain amplification of the signal, thereby realizing the function of the optical circulator + optical amplifier; greatly reducing the size, while being able to integrate other devices on the same chip, thereby constituting a more complex optical system, and having lower requirements for the manufacturing process; higher stability.

[0013] In the first aspect, the embodiments of the present application provide an optical circulator, which comprises a plurality of ports, a plurality of optical splitters and at least one pump light coupler, each port is provided with an optical splitter, and the output ends of the optical splitters of each port are connected in turn; after incident light enters a target port, the incident light is divided into clockwise signals and counterclockwise signals by the optical splitter of the target port; the pump light coupler outputs pump light, and the pump light is transmitted clockwise or counterclockwise in the optical circulator; if the pump light is transmitted clockwise in the optical circulator, the pump light and the clockwise signals have a Brillouin effect, and the clockwise signals are amplified; after the clockwise signals pass through the optical splitter of the next port of the target port, the clockwise signals are output from the next port of the target port; if the pump light is transmitted counterclockwise in the optical circulator, the pump light and the counterclockwise signals have a Brillouin effect, and the counterclockwise signals are amplified; after the counterclockwise signals pass through the optical splitter of the previous port of the target port, the counterclockwise signals are output from the previous port of the target port.

[0014] In the optional embodiments of the present application, if the pump light is transmitted clockwise in the optical circulator, the pump light and the counterclockwise signals do not have a Brillouin effect, and the counterclockwise signals are not amplified; if the pump light is transmitted counterclockwise in the optical circulator, the pump light and the clockwise signals do not have a Brillouin effect, and the clockwise signals are not amplified.

[0015] In the optional embodiments of the present application, the plurality of pump light couplers are respectively arranged at the output ends of the optical splitters of each port.

[0016] In the optional embodiments of the present application, the ports are connected by Brillouin active waveguides.

[0017] In the optional embodiments of the present application, if the pump light is transmitted clockwise in the optical circulator, the plurality of pump light couplers are respectively arranged at the output ends of the optical splitters of each port, which output the clockwise signals; if the pump light is transmitted counterclockwise in the optical circulator, the plurality of pump light couplers are respectively arranged at the output ends of the optical splitters of each port, which output the counterclockwise signals.

[0018] In the optional embodiments of the present application, each port is provided with a pump light input channel, and the pump light is transmitted to the optical circulator through the pump light input channel.

[0019] In optional embodiments of the present application, the optical circulator comprises a pump light coupler, and the optical circulator further comprises a ring resonator, wherein the clockwise signal, the counterclockwise signal and the pump light are transmitted in the ring resonator; the pump light and the clockwise signal have the Brillouin effect in the ring resonator, or the pump light and the counterclockwise signal have the Brillouin effect in the ring resonator.

[0020] In optional embodiments of the present application, the optical circulator is made of silicon material, silicon nitride material and chalcogenide glass.

[0021] In optional embodiments of the present application, the optical circulator is integrated in a chip.

[0022] In a second aspect, the embodiments of the present application further provide an optical device, which comprises the optical circulator.

[0023] The embodiments of the present application have the following beneficial effects:

[0024] The embodiments of the present application provide an optical circulator and an optical device, which can be realized in all-optical manner, reduce the dependence on additional components, easily expand the number of ports, more easily realize the requirement for more ports, do not need additional materials, reduce the process requirement, dynamically realize the change of the ring direction, can realize the gain amplification of the signal, thereby realize the function of the optical circulator + optical amplifier, greatly reduce the size, and can integrate other devices on the same chip, thereby constitute a more complex optical system, and have lower requirement for the manufacturing process, and have higher stability.

[0025] Other features and advantages of the present disclosure will be described in the following description, or can be inferred from the description or determined without doubt, or can be known by implementing the above-mentioned technologies of the present disclosure.

[0026] In order to make the above-mentioned purposes, features and advantages of the present disclosure more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0028] Figure 1 A schematic diagram of an optical circulator provided by the embodiments of the present application is shown in the following figure:

[0029] Figure 2A structural schematic diagram of an optical circulator provided by an embodiment of the present application is shown in FIG. 1.

[0030] Figure 3 A structural schematic diagram of another optical circulator provided by an embodiment of the present application is shown in FIG. 2.

[0031] Figure 4 A structural schematic diagram of an optical device provided by an embodiment of the present application is shown in FIG. 3. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described below in detail with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0033] At present, optical circulators can be divided into fiber optical circulators, spatial optical circulators and integrated optical circulators based on different optical platforms.

[0034] I. Fiber Optical Circulator

[0035] At present, the schemes for realizing fiber optical circulators and spatial optical circulators are mainly based on bulk materials, including: (1) Faraday optical rotation effect; (2) polarization beam splitter; and (3) birefringent crystal.

[0036] The entire scheme can include four ports. From left to right, the port positions are: port1 is the left upper port, port3 is the left lower port, port2 is the right upper port, and port4 is the right lower port. SMF is a single-mode optical fiber, SL is an optical fiber prism, BC is a birefringent crystal, QR1 and QR2 represent a counterclockwise 45-degree polarization rotating mirror and a clockwise 45-degree polarization rotating mirror respectively, and FR is a bismuth-substituted YIG 45° Faraday rotator 45-degree Faraday rotator.

[0037] Consider the path from port 1 to port 2 (the transmission direction is the Z axis), at position 1, the incident light contains two polarization components, the "dot" represents the polarization direction perpendicular to the paper (Y axis, this light is also called o light), the "horizontal line" represents the polarization direction parallel to the paper (X axis, this light is also called e light). After passing through the birefringent crystal (BC), at position 2, the o light and e light have different refraction angles, because the incident direction is perpendicular to the crystal surface, the transmission direction of the o light does not change, and the e light is refracted twice inside the crystal and then separated from the o light at the output. QR1 and QR2 represent a counterclockwise 45-degree polarization rotation and a clockwise 45-degree polarization rotation, respectively. After passing through QR1 and QR2, at position 3, the two beams of light will have the same polarization direction. After passing through FR (which acts to rotate the polarization direction counterclockwise by 45 degrees regardless of the transmission direction of the light), at position 4, the polarization directions of the two beams of light are both in the X axis direction. At this time, passing through the middle BC, the X axis polarization direction is the ordinary light direction, so from position 4 to position 5, the transmission position does not change. After passing through the second set of QR2 and QR1 and FR, and then passing through the last BC, the two separated polarized lights are output from port 2 at the same time, thereby realizing the transmission from port 1 to port 2.

[0038] The process from port 2 input is similar, but at this time the input light at position 5 is extraordinary light, so after passing through the middle BC, the light beam is refracted from above the y axis to below the y axis, and finally output from port 3. By analogy, the light output from port 3 will be output from port 4.

[0039] II. Integrated optical circulator

[0040] Scheme 1: Integrated magneto-optical material

[0041] An optical circulator can also be realized by wafer bonding or direct deposition of magneto-optical material on an integrated chip. For an integrated optical circulator bonded with garnet material on an SOI (Silicon-On-Insulator) chip. The silicon waveguide is an MZI structure, in which the upper arm of the MZI is a reciprocal phase shifter, providing a phase shift difference of pi / 2 between the upper and lower arms, and the lower arm of the MZI is a non-reciprocal phase shifter, in which the phase shift difference from left to right is -pi / 2, and the phase shift difference from right to left is pi / 2.

[0042] When incident from Port 1, it is divided into two beams of light by a 3dB coupler. At this time, the phase shift difference of the upper arm after passing through the reciprocal phase shifter is pi / 2, and the phase shift difference of the lower arm after passing through the non-reciprocal phase shifter is -pi / 2, and the total phase shift difference is 0. According to the transmission characteristics of the MZI, all the light is output from Port 2.

[0043] When the light is injected from Port2, it is divided into two beams by the 3dB coupler. At this time, the phase shift difference of the upper arm after the reciprocal phase shifter is pi / 2, and the phase shift difference of the lower arm after the non-reciprocal phase shifter is also pi / 2, and the total phase shift difference is pi. According to the transmission characteristics of the MZI, all the light is output from Port3.

[0044] Similarly, when the light is injected from Port3, it is output from Port4, and when the light is injected from Port4, it is output from Port1. Thus, the optical circulator is realized.

[0045] Scheme 2: based on PT (Parity-Time) symmetry breaking

[0046] The so-called PT symmetry refers to the state of a system after parity transformation and time transformation is the same as the original state. In the field of optics, it can be realized by constructing special materials or structures. The above scheme is realized based on a pair of directional couplers composed of special waveguides. In a pair of waveguides of the directional coupler, one waveguide has gain characteristics, and the other waveguide has loss characteristics. The refractive index satisfies the conditions that the real parts are equal, the imaginary parts are opposite in sign, and the absolute values are equal. In this special directional coupler, the coupling characteristics are as follows:

[0047] L→G arcsin(2 / K) / 2,

[0048] LG-L=pi / Q-arcsin(Ω / K) / Ω.

[0049] The meanings respectively represent the coupling length from the loss waveguide (L) to the gain waveguide (G) and the coupling length from the gain waveguide to the loss waveguide. And the total length of a whole period (from the loss waveguide to the gain waveguide and then to the loss waveguide, or from the gain waveguide to the loss waveguide and then to the gain waveguide) is a constant value. Based on this characteristic, the length of the coupler is set as the length of the loss waveguide (L) to the gain waveguide (G), and the directional couplers of different groups are connected through the loss waveguide.

[0050] When the light is injected from Port1, since the length of the coupler is not L G-L , it will be output into the gain waveguide and the loss waveguide at the output end at the same time, and the component transmitted to the loss waveguide is less, and then after passing through the intermediate connected loss waveguide, it is basically lost. The light power emitted from the gain waveguide is large, and after passing through the intermediate connected loss waveguide, it will experience loss, and then enter another group of directional couplers. At this time, since the light is injected from the loss waveguide, the length of the directional coupler is L L-G . Therefore, this part of the light will be completely output from Port2.

[0051] Based on this, the embodiment of the present application provides an optical circulator and an optical device, and specifically provides a full-optical integrated optical circulator. The full-optical implementation reduces the dependence on additional components, the number of ports is easy to expand, the demand for more ports is easier to achieve, no additional materials are needed, the process demand is reduced, the change of the circulator direction is dynamically achieved, the gain amplification of the signal is achieved, thereby realizing the function of the optical circulator+optical amplifier, the size is greatly reduced, and other devices can be integrated on the same chip to form a more complex optical system, and the requirement for the manufacturing process is lower, and the stability is higher.

[0052] In order to facilitate the understanding of the present embodiment, first, a kind of optical circulator disclosed in the present embodiment is introduced in detail.

[0053] Embodiment one:

[0054] The embodiment of the present application provides an optical circulator, referring to Figure 1 As shown in the schematic diagram of the optical circulator, the optical circulator comprises: a plurality of ports, a plurality of optical beam splitters and at least one pump light coupler, each port is provided with an optical beam splitter, and the output end of the optical beam splitter of each port is connected in turn;After the incident light enters the target port, the incident light is divided into clockwise signal and counterclockwise signal by the optical beam splitter of the target port;The pump light coupler outputs pump light, and the pump light is transmitted clockwise or counterclockwise in the optical circulator;If the pump light is transmitted clockwise in the optical circulator, the pump light and the clockwise signal occur Brillouin effect, and the clockwise signal is amplified;The clockwise signal passes through the optical beam splitter of the next port of the target port and is output from the next port of the target port;If the pump light is transmitted counterclockwise in the optical circulator, the pump light and the counterclockwise signal occur Brillouin effect, and the counterclockwise signal is amplified;The counterclockwise signal passes through the optical beam splitter of the previous port of the target port and is output from the previous port of the target port.

[0055] The optical circulator in the present embodiment can be provided with a plurality of ports, each port is provided with an optical beam splitter, and the optical circulator in the present embodiment can be provided with at least one pump light coupler. After the incident light enters the target port, it is divided into two beams of light by the optical beam splitter, which are clockwise signal and counterclockwise signal. The pump light output by the pump light coupler can be transmitted clockwise or counterclockwise in the optical circulator.

[0056] The clockwise transmitted pump light can occur Brillouin effect with the clockwise signal, thereby amplifying the clockwise signal, and the amplified clockwise signal can be output at the next port of the target port (the next port can be understood as the next port in the clockwise direction of the target port); the counterclockwise transmitted pump light can occur Brillouin effect with the clockwise signal, thereby amplifying the counterclockwise signal, and the amplified clockwise signal can be output at the previous port of the target port (the previous port can be understood as the previous port in the clockwise direction of the target port).

[0057] The optical circulator in the embodiment is realized based on stimulated Brillouin effect. First, the stimulated Brillouin effect is briefly introduced.

[0058] When the refractive index is periodically modulated, the propagation direction of the light field in the medium will change according to the momentum conservation. If the spatial periodic modulation is also time-varying, according to the Doppler effect, the light will satisfy the energy conservation and produce frequency shift. As Brillouin predicted, the dynamic grating of the space-time modulation generated by the mechanical wave will cause this scattering effect (referred to as Brillouin scattering effect). Brillouin scattering effect is a third-order nonlinear effect, and its intensity often exceeds the Kerr effect and Raman scattering effect. Brillouin scattering effect is derived from the coupling of the optical field and the acoustic field. It has an important position in laser physics and nonlinear optics. For a long time, the research on Brillouin scattering effect is mostly based on long-distance standard single-mode optical fiber, and the Brillouin gain spectrum is fixed, and the Brillouin frequency shift and other characteristics are determined by the optical fiber manufacturing process. In the past ten years, due to the development of micro-nano structure processing technology, the size of the device is continuously reduced. Up to now, there are still continuous researches on high-efficiency SBS (Stimulated Brillouin Scattering) in integrated optical waveguide by using different materials and waveguide structures.

[0059] The first problem to be solved for realizing SBS effect in integrated optical waveguide is how to confine both optical field and acoustic field. For example, although SOI waveguide (or silicon nanowire structure) can confine optical field well by total internal reflection, the high hardness of silicon material makes it difficult to confine acoustic field, thereby reducing the efficiency of acousto-optic interaction. Chalcogenide soft glass becomes the first integrated optical platform to realize SBS effect. Chalcogenide soft glass has high optical refractive index and low material hardness, and can confine both optical field and acoustic field in the material. In addition, mechanical isolation methods such as suspended silicon waveguide and microstructure waveguide with tapered pillars can be used to avoid acoustic field leakage from the core region of the optical waveguide to the substrate material. In addition to chalcogenide soft glass and mechanically isolated optical waveguide, the scheme based on ultra-low loss optical microcavity also successfully realizes on-chip SBS effect. Although this scheme does not confine the acoustic field and the SBS gain is not large enough, based on the characteristics of ultra-low optical loss and optical cavity resonance enhancing SBS effect, on-chip integrated SBS laser output is realized.

[0060] Regarding the non-reciprocity principle of Brillouin effect, Brillouin effect is the interaction of optical field and acoustic field, which needs to meet the phase matching condition. Taking forward stimulated Brillouin scattering (FSBS) as an example, when the pump light and the Stokes sideband are transmitted in the same direction, only the phonon in the same direction as the light transmission direction can participate in the Brillouin interaction because of the need to meet the phase matching condition, while the optical field and the acoustic field are in the opposite direction, and the interaction cannot occur because the phase matching condition is not met. Therefore, Brillouin effect has selectivity for the transmission direction of light, that is, it can realize the non-reciprocal transmission of light.

[0061] In the formula, the optical beam splitter can be a Y-branch, an MMI (Multi-Mode Interference), a directional coupler, etc. The pump light can be light of a specific frequency and mode that is phase-matched with the signal light, or a group of pump light and signal light, which generates phonon signal through Brillouin effect.

[0062] In addition, in some embodiments, if the pump light is transmitted clockwise in the optical circulator, the pump light does not have Brillouin effect with the counterclockwise signal, and the counterclockwise signal is not amplified; if the pump light is transmitted counterclockwise in the optical circulator, the pump light does not have Brillouin effect with the clockwise signal, and the clockwise signal is not amplified.

[0063] That is, in this embodiment, the clockwise-transmitted pump light will only produce a Brillouin effect with the clockwise signal, thereby amplifying the clockwise signal. The clockwise-transmitted pump light will not produce a Brillouin effect with the counterclockwise signal, thereby not amplifying the counterclockwise signal. The counterclockwise-transmitted pump light will only produce a Brillouin effect with the counterclockwise signal, thereby amplifying the counterclockwise signal. The counterclockwise-transmitted pump light will not produce a Brillouin effect with the clockwise signal, thereby not amplifying the clockwise signal.

[0064] Embodiments of the present invention provide an optical circulator that can be implemented all-optically, reducing reliance on additional components. The number of ports can be easily expanded, making it easier to meet the demand for more ports. No additional materials are required, reducing process requirements. The ring direction can be dynamically changed. Signal gain can be amplified, thereby realizing the functions of an optical circulator + an optical amplifier. The size is greatly reduced, and other devices can be integrated on the same chip to form an optical system with more complex functions, reducing the manufacturing process requirements. The stability is higher.

[0065] Example 2:

[0066] This embodiment provides another optical circulator, which is implemented based on the above embodiment. In some embodiments, the plurality of pump optical couplers are respectively provided at the output end of each port.

[0067] See Figure 2 The schematic diagram of the structure of an optical circulator is shown in FIG. Figure 2 Shown in FIG is a three-port optical circulator. Figure 2 The figure shows a multi-port ring structure based on optical beam splitters and optical couplers. Each port is split into two optical signals by the optical beam splitter. The outputs of the optical beam splitters at different ports are then connected in sequence to form a ring structure. In addition, a pump light coupler is located at each output of the optical beam splitter to couple the pump light.

[0068] like Figure 2 As shown, taking port 1 as an example, the incident light ( Figure 2 The solid line in the figure indicates the incident direction of the signal) enters port 1 and is divided into two beams of signals through the optical beam splitter, namely clockwise signal and counterclockwise signal. At this time, the pump light ( Figure 2 The pump light injection direction is indicated by the dotted line in the figure. The pump light is transmitted clockwise in the ring structure. Therefore, only the clockwise incident light is amplified due to the Brillouin effect and then output from port 2 through the optical beam splitter near port 2. The counterclockwise incident light component cannot be amplified because it does not meet the phase matching condition, so the output power at port 3 is low.

[0069] The number of ports of the optical circulator in this embodiment can be expanded. Figure 2The triangles do not represent the actual shape of the device.

[0070] In some embodiments, the ports are connected by Brillouin active waveguide. The Brillouin active waveguide can include, but is not limited to, the following three schemes: fully suspended Brillouin active waveguide, partially suspended Brillouin active waveguide, and chalcogenide glass waveguide.

[0071] In some embodiments, if the pump light is transmitted clockwise in the optical circulator, the plurality of pump light couplers are respectively arranged at the output ends of the optical beam splitters outputting the clockwise signals of each port; if the pump light is transmitted counterclockwise in the optical circulator, the plurality of pump light couplers are respectively arranged at the output ends of the optical beam splitters outputting the counterclockwise signals of each port.

[0072] As shown in Figure 2 If the clockwise path is used, i.e. port 1→port 2→port 3, only the clockwise pump light coupler needs to be made; if port 1→port 3→port 2, only the counterclockwise pump light coupler needs to be made.

[0073] In some embodiments, each port is configured with a pump light input channel, and the pump light is transmitted to the optical circulator through the pump light input channel. Each port needs to realize ring transmission, and in this embodiment, a pump light input channel needs to be configured for each port.

[0074] Embodiment three:

[0075] This embodiment provides another optical circulator, which is realized on the basis of the above-mentioned embodiments. In some embodiments, the above-mentioned optical circulator comprises a pump light coupler, and the optical circulator further comprises a ring resonant cavity; the clockwise signal, the counterclockwise signal and the pump light are transmitted in the ring resonant cavity; the pump light and the clockwise signal have Brillouin effect in the ring resonant cavity, or the pump light and the counterclockwise signal have Brillouin effect in the ring resonant cavity.

[0076] Referring to another structural schematic diagram of an optical circulator shown in Figure 3 In the three-port optical circulator shown in Figure 3 In the three-port optical circulator shown in Figure 3 In the three-port optical circulator shown in In the three-port optical circulator shown in

[0077] Compared with the optical circulator provided by the foregoing embodiments, the optical circulator provided by the present embodiment only needs one pump light coupler to realize injection of pump light, and in addition, changing the circulator direction only needs to change the injection direction of the pump light. Moreover, due to the existence of the circulator resonant cavity, the photon and phonon signals in the cavity are stronger, and therefore the Brillouin gain effect is stronger, and higher channel isolation can be realized.

[0078] The optical circulator provided by the present application has the following advantages.

[0079] 1. Compared with the conventional scheme based on the magneto-optical effect, the optical circulator can be realized optically without an external magnetic field, and the dependence on additional components is greatly reduced.

[0080] 2. Compared with some existing four-port devices, the number of ports of the optical circulator is easy to expand, and the demand for more ports can be more easily realized.

[0081] 3. Compared with some existing schemes that combine magneto-optical materials, the magneto-optical effect scheme has a lattice mismatch due to wafer bonding, and the deposition material process is also very complex. In some embodiments, the optical circulator is made of silicon material, silicon nitride material and chalcogenide glass. The present application can be based on existing Si material, silicon nitride material and chalcogenide glass, without the need for additional materials, thereby reducing the process requirements.

[0082] 4. The present application is based on the non-reciprocal gain of the Brillouin effect, and can dynamically realize the change of the circulator direction.

[0083] 5. Although the present application causes energy loss due to the existence of the optical beam splitter, due to the existence of the Brillouin effect gain, even the gain amplification of the signal can be realized, thereby realizing the function of the optical circulator + optical amplifier.

[0084] 6. Compared with some existing spatial light schemes, in some embodiments, the optical circulator is integrated in a chip. The present application can be an integrated platform, and the size of the device is greatly reduced; at the same time, other devices can be integrated on the same chip, thereby constituting a more complex optical system.

[0085] 7. The spatial light circulator needs to be strictly aligned with the optical path, and the manufacturing process requirement is high; the present application has a lower manufacturing process requirement.

[0086] 8. Compared with some existing magneto-optical + MZI schemes, the present application is based on intensity gain, and is more stable than the phase interference scheme.

[0087] In conclusion, the optical circulator can be constructed by using the non-reciprocity of Brillouin effect, and can be constructed by using simple devices and structures such as an optical beam splitter, an optical coupler and a ring structure; the optical circulator can be based on an existing material system, and does not need additional processes and materials, and is easy to implement; the optical circulator can be highly reconfigurable, and parameters such as the number of ports, the ring direction and the channel crosstalk (isolation) can be customized.

[0088] Embodiment four:

[0089] Corresponding to the above embodiment, the embodiment of the present application provides an optical device, referring to Figure 4 The optical device includes the optical circulator provided in the above embodiment.

[0090] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the optical device described above can refer to the corresponding process in the above-mentioned embodiment of the optical circulator, which will not be described here.

[0091] In addition, in the description of the embodiment of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0092] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0093] Finally, it should be noted that the above-described embodiments are merely specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, but not to limit the same. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that any person skilled in the art can still modify or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some of the technical features, within the technical scope disclosed by the present application. The modifications, changes or replacements do not cause the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An optical circulator, characterized in that: The optical circulator comprises: a plurality of ports, a plurality of optical beam splitters and at least one pump optical coupler, each of the ports is provided with the optical beam splitter, and the output ends of the optical beam splitters of each port are connected in sequence; After the incident light enters the target port, the incident light is split into a clockwise signal and a counterclockwise signal by the optical beam splitter of the target port; The pump light coupler outputs pump light, and the pump light is transmitted clockwise or counterclockwise in the optical circulator; If the pump light is transmitted clockwise in the optical circulator, the pump light and the clockwise signal generate a Brillouin effect, and the clockwise signal is amplified; the clockwise signal passes through the optical beam splitter of the port next to the target port in the clockwise direction, and is output from the port next to the target port in the clockwise direction; If the pump light is transmitted counterclockwise in the optical circulator, the pump light and the counterclockwise signal generate a Brillouin effect, and the counterclockwise signal is amplified; after the counterclockwise signal passes through the optical beam splitter of the port preceding the target port in the clockwise direction, it is output from the port preceding the target port in the clockwise direction; If the pump light is transmitted clockwise in the optical circulator, the pump light and the counterclockwise signal do not produce a Brillouin effect, and the counterclockwise signal is not amplified; if the pump light is transmitted counterclockwise in the optical circulator, the pump light and the clockwise signal do not produce a Brillouin effect, and the clockwise signal is not amplified.

2. The optical circulator according to claim 1, wherein: A plurality of pump optical couplers are respectively arranged at the output end of each port.

3. The optical circulator according to claim 2, wherein: The ports are connected by Brillouin active waveguides.

4. The optical circulator according to claim 2, wherein: If the pump light is transmitted clockwise in the optical circulator, a plurality of pump light couplers are respectively provided at the output end of the optical beam splitter of each port outputting the clockwise signal; If the pump light is transmitted counterclockwise in the optical circulator, a plurality of pump light couplers are respectively provided at the output end of the optical beam splitter of each port that outputs the counterclockwise signal.

5. The optical circulator according to claim 2, wherein: Each of the ports is configured with a pump light input channel, and the pump light is transmitted to the optical circulator through the pump light input channel.

6. The optical circulator according to claim 1, wherein: The optical circulator includes: a pump optical coupler, and the optical circulator also includes: a ring resonator; The clockwise signal, the counterclockwise signal and the pump light are all transmitted in the ring resonator; the pump light and the clockwise signal produce a Brillouin effect in the ring resonator, or the pump light and the counterclockwise signal produce a Brillouin effect in the ring resonator.

7. The optical circulator according to any one of claims 1 to 6, characterized in that: The optical circulator is made based on silicon material, silicon nitride material and chalcogenide glass.

8. The optical circulator according to any one of claims 1 to 6, characterized in that: The optical circulator is integrated into a chip.

9. An optical device, characterized in that: The optical device comprises the optical circulator according to any one of claims 1 to 8.

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