Optical isolation device and method based on dual-cavity optical force system

Abstract

The present invention discloses an optical isolation device and method based on a dual-cavity optical force system, belonging to the field of optical device technology in modern information networks, comprising: a dual-cavity optical force system, a driving light input unit, and a detection light input unit; the dual-cavity optical force system includes a left optical cavity, a right optical cavity, and a mechanical oscillator, with the mechanical oscillator being located between the left and right optical cavities; the left and right optical cavities interact with each other through linear coupling; the driving light input unit and the detection light input unit are both used to input light of preset amplitude and frequency into the left and right optical cavities, respectively. The optical isolator based on the dual-cavity optical force system of the present invention can achieve perfect optical isolation, that is, light can be completely transmitted from one side of the system to the other side without energy loss, while when light is transmitted in the opposite direction, the output is completely prohibited by the system; at the same time, the optical isolator based on the dual-cavity optical force system is small in size and can be integrated on a chip with existing superconducting technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical devices in modern information networks, and in particular relates to an optical isolation device and method based on a dual-cavity optical force system. Background Art

[0002] Optical isolators are devices that allow only one-way transmission of optical signals. Their ability to effectively suppress erroneous or unwanted optical signals makes them indispensable quantum devices in modern information processing. For example, they can protect devices from noise emitted by electronic devices in quantum superconducting circuits. Unidirectional signal transmission generally requires a system that exhibits optical nonreciprocity, i.e., a violation of optical reciprocity. To achieve asymmetric transmission by breaking reciprocity, any such device must break time reversal symmetry. Traditionally, nonreciprocal transmission relies on a strong external magnetic field to break the system's time reversal symmetry. However, the high magnetic field conditions make these conventional devices bulky and incompatible with ultra-low-loss superconducting circuits. Recently, cavity optomechanical systems have been proposed as an alternative to traditional nonreciprocal devices. These systems are particularly promising because they can be integrated with existing superconducting technologies on chips. However, these cavity optomechanical schemes do not address the problem of perfect optical isolation, where light can be fully transmitted from one side of the system to the other without energy loss, while the output is completely inhibited in the opposite direction, resulting in zero output. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention proposes an optical isolation device and method based on a dual-cavity optical force system to solve the problems existing in the above-mentioned prior art.

[0004] To achieve the above objectives, the present invention provides an optical isolation device based on a dual-cavity optomechanical system, comprising:

[0005] Dual-cavity optical force system, driving light input unit, detection light input unit;

[0006] The dual-cavity optical force system includes a left optical cavity, a right optical cavity and a mechanical oscillator, wherein the mechanical oscillator is located between the left optical cavity and the right optical cavity; the left optical cavity and the right optical cavity of the dual-cavity optical force system interact with each other through linear coupling;

[0007] The driving light input unit and the detecting light input unit are both used to input light of preset amplitude and frequency into the left and right optical cavities respectively.

[0008] Alternatively, the linear coupling strength expression between the left optical cavity and the right optical cavity is:

[0009] ;

[0010] Where, are the dissipation rates of the left and right optical cavities, respectively.

[0011] Optionally, the expression of the optical coupling coefficient of the dual-cavity optical force system is:

[0012] ;

[0013] Where, For the The optical coupling coefficient of the optical force interaction between the optical cavity and the mechanical oscillator is For the The dissipation rate of an optical cavity, is the dissipation rate of the mechanical oscillator.

[0014] Optionally, the driving light input unit inputs light of preset amplitude and frequency into the left and right optical cavities to form a driving field, and the frequency detuning of the driving field satisfies a mechanical red detuning condition.

[0015] Optionally, the phase difference of the driving field is .

[0016] The present invention also provides an optical isolation method based on a dual-cavity optomechanical system, comprising the following steps:

[0017] Set the dissipation rates of the left and right optical cavities to be , the dissipation rate of the mechanical oscillator is , and adjust the linear coupling strength between the left and right cavities to satisfy ;

[0018] Input the driving light of preset frequency into the left optical cavity and the right optical cavity, and adjust the driving field phase difference to , so that the photomechanical coupling coefficient satisfies ;in 、 are the optical-mechanical coupling constants between the left and right cavities and the mechanical oscillator, respectively;

[0019] Select the left or right optical cavity to input the probe light of the preset frequency, detect the output field amplitude, and verify whether the forward transmission amplitude and the reverse transmission amplitude meet the requirements;

[0020] By adjusting the dissipation rate of the mechanical oscillator or the driving field strength, it can adapt to different frequency band requirements.

[0021] Optionally, the dissipation rates of the left optical cavity and the right optical cavity are equal or proportional.

[0022] The present invention also provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above method.

[0023] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the above method when executed by a processor.

[0024] The present invention also provides a computer program product, comprising a computer program, which implements the steps of the above method when executed by a processor.

[0025] Compared with the prior art, the present invention has the following advantages and technical effects:

[0026] The optical isolator based on the dual-cavity optomechanical system of this invention achieves perfect optical isolation. Light can be fully transmitted from one side of the system to the other without energy loss, while light output is completely blocked by the system when transmitted in the opposite direction, achieving perfect optical isolation. Furthermore, the optical isolator based on the dual-cavity optomechanical system is compact and can be integrated on a chip with existing superconducting technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0028] Figure 1 Schematic diagram of an optical isolator according to an embodiment of the present invention, (a) is a dual-cavity optical force system, and (b) is a schematic diagram of the optical force interaction between the dual-cavity optical force system and the intermediate mechanical oscillator;

[0029] Figure 2 is the non-reciprocal angle of the embodiment of the present invention The curve of transmission amplitude changing with relative frequency detuning;

[0030] Figure 3 is the non-reciprocal angle of the embodiment of the present invention Schematic diagram of the effect of cavity dissipation on the transmission amplitude;

[0031] Figure 4 is the non-reciprocal angle of the embodiment of the present invention Schematic diagram of the effect of mechanical oscillator dissipation on the transmission amplitude. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0034] Example 1

[0035] like Figure 1-4 As shown, this embodiment provides an optical isolation device based on a dual-cavity optical force system, including:

[0036] 1. The structure of the dual-cavity optomechanical system;

[0037] The dual-cavity optomechanical system consists of three parts: two left and right optical cavities and a middle mechanical oscillator. Figure 1 (a) shows the mechanical oscillator (eigenfrequency is ) are used as the annihilation operator and the creation operator respectively. and Represents and satisfies the commutation relation Assume that the optical cavity frequencies on both sides are , and the annihilation (creation) operators are respectively and Respectively, the operators satisfy the commutation relation and ( ). The optical cavity and uniform mechanical oscillator Optical force interaction occurs, and the interaction Hamiltonian is ,in 、 is the photomechanical coupling constant. Through linear coupling with the cavity There is an interaction, and the interaction Hamiltonian is ,in is the coupling strength. The two beam frequencies are The amplitude is and The driving light drives the optical cavity from the left and right sides respectively and . At the same time, the frequency is The amplitude is and The detection light is input into the optical cavity from the left and right sides respectively. and . Then the Hamiltonian of the entire system is ( ).

[0038] (1)

[0039] The last four terms in the above equation are the left and right detection lights, the left and right driving fields, and the optical cavity. and The Hamiltonian of the interaction between. The above formula has multiple time In order to simplify the above formula, the coordinate system is made along the driving field frequency Do the rotation, the Hamiltonian after the rotation is:

[0040] (2)

[0041] in is the frequency detuning between the optical cavity and the driving field, is the frequency detuning between the detection field and the driving field.

[0042] 2. Heisenberg-Langevin equation and its linearization;

[0043] From the Hamiltonian of the system, it can be concluded that the Heisenberg-Langevin equation satisfied by the system operator is:

[0044] (3)

[0045] 、 and are the dissipation rates of the left and right optical cavities and the mechanical oscillator, 、 and are the vacuum noise operators of the left and right optical cavities and the mechanical oscillator respectively. The average values ​​of these noises are all zero, i.e. Since the main research is on the average optical response of the dual-cavity optomechanical system to the probe light, the influence of these noises can be ignored in this embodiment.

[0046] In order to obtain the average value equation of each operator in the system, when there is no detection field input ( ), we can use the operator factorization assumption commonly used in cavity optomechanics, that is, Therefore, from formula (3), we can get the steady-state mean of each operator as:

[0047] (4)

[0048] in , Respectively represent the effective detuning between the left and right optical cavities and the driving field. When there is a detection field input, the system operator can be written as the sum of the operator mean and the fluctuation operator, that is:

[0049] , , (5)

[0050] The fluctuation operator is generally much smaller than the operator mean. Therefore, when substituting (5) into (3), we can only keep the linear term of the fluctuation operator and use the substitution , , The linearized Heisenberg-Langevin equation is then:

[0051] (6)

[0052] in, , Without loss of generality, we can assume 、 and are all positive real numbers. It can be seen from formula (4) that by regulating the driving field amplitude and Can effectively adjust the photomechanical coupling coefficient and Phase difference between Phase difference It is the key parameter that enables the system to show optical non-reciprocity. In addition, for the sake of simplicity, the fluctuation operator use ( )replace.

[0053] If the frequency of the driving field satisfies the mechanical red detuning, that is, , and the frequency of the mechanical oscillator Much greater than and , the rotation wave approximation can be used to simplify equation (6) to:

[0054] (7)

[0055] in, .

[0056] Since Equation (7) is a linear equation and has only one time exponential factor , so it has the form The solution, .Bundle Substituting into (7), we can get:

[0057] (8)

[0058] as well as .

[0059] 3. Output field of the optical cavity;

[0060] In order to study the optical nonreciprocity of the system, it is necessary to study the output fields of the two optical cavities and The properties of the output field can be derived from the input-output relationship of the optical cavity, namely:

[0061] (9)

[0062] in . Still using the assumptions mentioned above , we can get the solution of the output field as:

[0063] (10)

[0064] as well as .

[0065] 4. Optical isolator;

[0066] If the above optical force system is to realize the function of optical isolator, light can only be transmitted in one direction, which means that light input from one side cannot be output from the other side, that is, the output must be zero. If the signal intensity is required to remain unchanged when it is transmitted in one direction, the detection field is Towards The transmission amplitude The following conditions must be met:

[0067] , (11)

[0068] or,

[0069] , (12)

[0070] The subscript ( ) indicates that the detection field is ( ) side has no input signal. For the convenience of description, the following content will omit these subscripts. , and the transmission amplitude Abbreviated as .

[0071] From formulas (8) and (10), we can conclude that:

[0072] (13)

[0073] (14)

[0074] From formula (13), we can see that when ( )or , the system will not have non-reciprocity, so the origin of the system's non-reciprocity lies in the interaction of light force 、 Interaction with linear coupling The quantum interference effect between them. Below we take Equation (11) as an example to study the generation mechanism of optical isolators. If Equation (11) is to hold, then Equation (14) must be equal to zero. Then, from the condition that the numerator of Equation (14) is zero, we can conclude that:

[0075] (15)

[0076] The left side of the above equation is a complex number. If the above equation is to be valid, the real and imaginary parts of the left side must be zero at the same time, so the following equation is valid:

[0077] (16)

[0078] Formula (16) is the necessary condition for the system to produce optical isolation effect, that is, when the condition (16) is established, it can be known from formula (11) that ,and Non-zero, thus achieving unidirectional transmission.

[0079] In fact, it can be easily seen from equations (13) and (14) that when or When the integer multiple of , equations (13) and (14) are completely equal, that is, , then the system has no non-reciprocity. So if the system wants to show non-reciprocity, this non-reciprocity angle The value of must be non-zero. For example, when And the dissipation rate When , it can be found that when the system parameters satisfy equations (17) and (18), the system can exhibit perfect non-reciprocity, such as Figure 2 shown.

[0080] (17)

[0081] (18)

[0082] When the non-reciprocal angle When , we can know from (16) , then equations (13) and (14) are simplified to:

[0083] (19)

[0084] (20)

[0085] when When , we can know from (16) , substituting it into equations (19) and (20), we can obtain:

[0086] (twenty one)

[0087] (twenty two)

[0088] To achieve ideal optical isolation, the following equation holds:

[0089] (twenty three)

[0090] From formula (23), we can get the unique solution:

[0091] (twenty four)

[0092] From formula (16), we can see that the linear coupling constant is:

[0093] (25)

[0094] That is, when the parameters satisfy (24) and (25), the system can exhibit perfect optical isolation effect, such as Figure 3 and Figure 4 shown.

[0095] This embodiment also provides an optical isolation method based on a dual-cavity optical force system. Figure 1 (b) is a structural diagram of the scheme, including:

[0096] Step 1: Adjust the intensity and phase of the two driving fields in the system so that the effective photomechanical coupling constant 、 satisfy ( ) (see equation (24)) and the non-reciprocal angle Adjust the linear coupling strength between the two dual cavities , so that the dissipation rate of the two cavities satisfies , see formula (25).

[0097] Step 2: When the system parameters meet the conditions in step 1, this embodiment numerically simulates the mechanical oscillator dissipation rate The influence of the size of the unidirectional transmission characteristics of light. In this embodiment, the dissipation rate of the mechanical oscillator is taken as , , , When the transmission amplitude (black dashed line) and (Red solid line) As the relative frequency detuning The change curve of other parameters , see attached Figure 4(a)-4(d). It can be clearly seen from the figure that the size of the mechanical oscillator dissipation rate has a significant impact on the width and size of the transmission amplitude spectrum. As long as the coupling strength satisfies equations (24) and (25), Perfect optical isolation is achieved everywhere.

[0098] This embodiment further provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above method.

[0099] This embodiment further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0100] This embodiment also provides a computer program product, including a computer program, which implements the steps of the above method when executed by a processor.

[0101] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. An optical isolation device based on a dual-cavity optical force system, characterized in that: include: Dual-cavity optical force system, driving light input unit, detection light input unit; The dual-cavity optical force system includes a left optical cavity, a right optical cavity and a mechanical oscillator, wherein the mechanical oscillator is located between the left optical cavity and the right optical cavity; the left optical cavity and the right optical cavity of the dual-cavity optical force system interact with each other through linear coupling; The driving light input unit and the detecting light input unit are both used to input light of preset amplitude and frequency into the left and right optical cavities respectively; The linear coupling strength expression between the left optical cavity and the right optical cavity is: ； Where, are the dissipation rates of the left and right optical cavities, respectively; The expression of the optical coupling coefficient of the dual-cavity optical force system is: ； Where, For the The optical coupling coefficient of the optical force interaction between the optical cavity and the mechanical oscillator is For the The dissipation rate of an optical cavity, is the dissipation rate of the mechanical oscillator; The driving light input unit inputs light of preset amplitude and frequency into the left and right optical cavities to form a driving field, and the frequency detuning of the driving field satisfies the mechanical red detuning condition; The phase difference of the driving field is .

2. An optical isolation method based on a dual-cavity optomechanical system, characterized in that: The following steps are involved: Set the dissipation rates of the left and right optical cavities to be , the dissipation rate of the mechanical oscillator is , and adjust the linear coupling strength between the left and right cavities to satisfy ; Input the driving light of preset frequency into the left optical cavity and the right optical cavity, and adjust the driving field phase difference to , so that the photomechanical coupling coefficient satisfies ;in 、 are the optical-mechanical coupling constants between the left and right cavities and the mechanical oscillator, respectively; Select the left or right optical cavity to input the probe light of the preset frequency, detect the output field amplitude, and verify whether the forward transmission amplitude and the reverse transmission amplitude meet the requirements; By adjusting the dissipation rate of the mechanical oscillator or the driving field strength, it can adapt to different frequency band requirements.

3. The optical isolation method based on a dual-cavity optomechanical system according to claim 2, characterized in that: The dissipation rates of the left optical cavity and the right optical cavity are equal or proportional.

4. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method according to any one of claims 2 to 3.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 2 to 3 are implemented.

6. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 2 to 3 are implemented.

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