On-chip sensitivity enhancement method and system for interferometer

Abstract

The application provides a sensitivity enhancement method and system on chip for an interferometer, which comprises three sub-modules, including: an input modulation sub-module, a bias point modulation sub-module and an output modulation sub-module. The input modulation sub-module is used for pre-selectively modulating an initial input optical signal and inputting the initial input optical signal into the bias point modulation sub-module; the bias point sub-module is used for splitting and outputting the signal light, and performing phase modulation on the light at the waveguide branch; and the output modulation sub-module is used for post-selectively modulating the signal light and splitting and outputting two signal lights. The sensitivity enhancement module on chip for the interferometer provided by the application can amplify a tiny signal by using a weak measurement method, so that the sensitivity of the interferometer is enhanced. The module can replace an interference module in a traditional interferometer, while the external parameter sensitive path is reserved, so that the sensitivity of the interferometer is greatly improved.

Description

Technical Field

[0001] This invention relates to the technical field of measurement technology, and more specifically, to an on-chip sensitivity enhancement method and system for interferometers. Background Technology

[0002] Optical interferometry plays a crucial role in precision measurement; for example, optical interferometers are widely used in precision measurements such as gravitational wave detection, gyroscopes, and environmental sensing. In classical optical interferometry, the sensitivity limit is the shot noise limit, but this limit is often not reached in practical applications. The working principle of a traditional optical interferometer is to interfere with a reference beam and a signal beam. When the reference and signal beams travel different paths, their phase changes are reflected in the intensity changes of the interferometer. The distance traveled is calculated by observing the intensity changes after interference, i.e., the changes in the bright and dark fringes of the interferogram. However, its measurement accuracy is directly limited by the wavelength of the light. Due to the limitation of the measurement sensitivity of optical interferometers, their role in high-precision measurements is very limited. Therefore, improving the measurement accuracy of optical interferometers has become an urgent problem to be solved.

[0003] Quantum precision measurement is a high-precision measurement method that has been vigorously developed in recent years, and weak measurement techniques are a part of quantum precision measurement. Weak measurement techniques, by selecting appropriate pre-selection and post-selection operations, amplify the minute phase change between the horizontal and vertical polarization of a beam of light to an observable position. This process sacrifices a significant amount of light intensity in exchange for high-precision measurement. Weak measurement techniques have attracted widespread attention from researchers due to their extremely high sensitivity in measuring minute phase changes.

[0004] Weak measurements include standard imaginary part weak measurements, bias weak measurements, combined weak measurements, and dual-path weak measurements. Studies show that when measuring minute phase shifts, the accuracy of standard imaginary part weak measurements is three orders of magnitude higher than that of standard interferometry. Dual-path weak measurements are three orders of magnitude more accurate than standard imaginary part weak measurements, while bias and combined weak measurements are two orders of magnitude more accurate. This means that introducing weak measurement techniques into interferometers can improve their measurement sensitivity by at least three orders of magnitude, enabling high-precision measurements.

[0005] Therefore, a new technical solution is needed to improve the above-mentioned technical problems. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the purpose of this invention is to provide an on-chip sensitivity enhancement method and system for interferometers.

[0007] According to the present invention, an on-chip sensitivity enhancement method for an interferometer is provided, the method comprising the following steps:

[0008] Step S1: Input the initial optical signal;

[0009] Step S2: The input modulation submodule performs polarization state pre-selective modulation on the input initial optical signal and inputs it into the bias point modulation submodule;

[0010] Step S3: The bias point modulation submodule splits the modulated optical signal into beams and performs phase modulation on the bias point of the optical signal at the waveguide branch.

[0011] Step S4: The output modulation module polarizes the optical signal, selects modulation, and splits the signal into two beams for output.

[0012] Preferably, step S2 includes the following steps:

[0013] Step S2.1: Filter the polarization state of the initial optical signal input at the first port and complete the polarization state pre-modulation selection;

[0014] Step S2.2: Introduce the optical signal into the beam splitter, split the optical signal into beams, and input them into the bias point control submodule.

[0015] Preferably, step S3 includes the following steps:

[0016] Step S3.1: The optical signal from the input bias point control submodule is split into two optical signals, namely a horizontally polarized optical signal and a vertically polarized optical signal, through the Y waveguide. The two optical signals enter the two waveguide arms of the Y branch respectively.

[0017] Step S3.2: Apply voltage to the electrodes on the Y branch to perform phase modulation of the polarization state of the optical signal on the branch, modulate the bias point, and output to the second port and the third port respectively;

[0018] Step S3.3: The optical signal is output from the second port and the third port to the external interference module. This process is a weak coupling process, and the physical quantity to be measured is coupled into the system through this process. After that, the optical signal returns from the second port and the third port and is beamed at the Y waveguide. The beamed optical signal enters the beam splitter in the input modulation submodule and is transmitted into the output modulation submodule.

[0019] Preferably, step S4 includes the following steps:

[0020] Step S4.1: Perform polarization state filtering on the optical signals of the input and output modulation submodules, and select the modulation mode after polarization state filtering;

[0021] Step S4.2: The modulated optical signal enters the beam splitter and is split into two beams. The two beams are modulated separately. After the polarization state is completed, the modulation is selected and then output to the fourth and fifth ports.

[0022] Preferably, in step S1: the initial optical signal is incident from the first port, polarized by a polarizer with an optical axis angle of 45°, completing the pre-selection process. The pre-selection state is represented as follows: |H> and |V> represent horizontal polarization and vertical polarization, respectively.

[0023] The present invention also provides an on-chip sensitivity enhancement system for an interferometer, the system comprising the following modules:

[0024] Module M1: Input initial optical signal;

[0025] Module M2: The input modulation submodule performs polarization state pre-selective modulation on the input initial optical signal and inputs it into the bias point modulation submodule;

[0026] Module M3: The bias point modulation submodule splits the modulated optical signal into beams and performs phase modulation on the bias point of the optical signal at the waveguide branch.

[0027] Module M4: The output modulation module polarizes the optical signal, selects modulation, and splits it into two beams of optical signal.

[0028] Preferably, module M2 includes the following modules:

[0029] Module M2.1: Filters the polarization state of the initial optical signal input from the first port and selects modulation before completing the polarization state selection;

[0030] Module M2.2: Introduces the optical signal into the beam splitter, splits the optical signal into beams, and inputs them to the bias point control submodule.

[0031] Preferably, module M3 includes the following modules:

[0032] Module M3.1: The optical signal from the input bias point control submodule is split into two optical signals, namely a horizontally polarized optical signal and a vertically polarized optical signal, through the Y-waveguide. The two optical signals enter the two waveguide arms of the Y branch respectively.

[0033] Module M3.2: By applying voltage to the electrodes on the Y branch, the polarization state of the optical signal on the branch is phase-modulated, the bias point is modulated, and the output is sent to the second port and the third port respectively;

[0034] Module M3.3: The optical signal is output from the second and third ports to the external interference module. This process is a weak coupling process, through which the physical quantity to be measured is coupled into the system. Afterward, the optical signal returns from the second and third ports and is combined at the Y waveguide. The combined optical signal enters the beam splitter in the input modulation submodule and is then transmitted into the output modulation submodule.

[0035] Preferably, module M4 includes the following modules:

[0036] Module M4.1: Performs polarization state filtering on the optical signals from the input and output modulation submodules, and selects the modulation mode after polarization state filtering;

[0037] Module M4.2: The modulated optical signal enters the beam splitter and is split into two beams. The two beams are modulated separately. After the polarization state is completed, the modulation is selected and then output to the fourth and fifth ports.

[0038] Preferably, in module M1: the initial optical signal is incident from the first port, polarized by a polarizer with an optical axis angle of 45°, completing the pre-selection process. The pre-selection state is represented as follows: |H> and |V> represent horizontal polarization and vertical polarization, respectively.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. This invention introduces weak measurement technology into the interferometer module to improve the problem of low measurement sensitivity in existing interferometers;

[0041] 2. Without changing the structure of the interferometer's light source input, interference module, and output detector, a sensitivity enhancement module for the interferometer is proposed. By simply replacing the modulation part of the traditional interferometer with the sensitivity enhancement module of this invention, a significant improvement in measurement accuracy can be achieved.

[0042] 3. The on-chip sensitivity enhancement module for interferometers provided by the present invention utilizes the characteristic of weak measurement methods to amplify small signals, thereby enhancing the sensitivity of the interferometer.

[0043] 4. The on-chip sensitivity enhancement module for interferometers of the present invention can replace the interferometer module in a traditional interferometer while retaining the external parameter sensitive path, thereby greatly improving the sensitivity of the interferometer. Attached Figure Description

[0044] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0045] Figure 1 This is a schematic diagram of the on-chip interferometer sensitivity enhancement module of the present invention;

[0046] Figure 2 This is a schematic diagram of an example of the on-chip interferometer sensitivity enhancement module of the present invention;

[0047] Figure 3 This is a schematic diagram of an example of the on-chip interferometer sensitivity enhancement module of the present invention;

[0048] Figure 4This is an application example diagram of the on-chip interferometer sensitivity enhancement module of the present invention;

[0049] Figure 5 This is an application example diagram of the on-chip interferometer sensitivity enhancement module of the present invention. Detailed Implementation

[0050] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0051] Example 1:

[0052] According to the present invention, an on-chip sensitivity enhancement method for an interferometer is provided, the method comprising the following steps:

[0053] Step S1: Input the initial optical signal; the initial optical signal is incident from the first port, polarized by the polarizer, the optical axis angle of the polarizer is 45°, completing the pre-selection process. The pre-selection state is represented as: |H> and |V> represent horizontal polarization and vertical polarization, respectively.

[0054] Step S2: The input modulation submodule performs polarization state pre-selective modulation on the input initial optical signal and inputs it into the bias point modulation submodule;

[0055] Step S2.1: Filter the polarization state of the initial optical signal input at the first port and complete the polarization state pre-modulation selection;

[0056] Step S2.2: Introduce the optical signal into the beam splitter, split the optical signal into beams, and input them into the bias point control submodule.

[0057] Step S3: The bias point modulation submodule splits the modulated optical signal into beams and performs phase modulation on the bias point of the optical signal at the waveguide branch.

[0058] Step S3.1: The optical signal from the input bias point control submodule is split into two optical signals, namely a horizontally polarized optical signal and a vertically polarized optical signal, through the Y waveguide. The two optical signals enter the two waveguide arms of the Y branch respectively.

[0059] Step S3.2: Apply voltage to the electrodes on the Y branch to perform phase modulation of the polarization state of the optical signal on the branch, modulate the bias point, and output to the second port and the third port respectively;

[0060] Step S3.3: The optical signal is output from the second port and the third port to the external interference module. This process is a weak coupling process, and the physical quantity to be measured is coupled into the system through this process. After that, the optical signal returns from the second port and the third port and is beamed at the Y waveguide. The beamed optical signal enters the beam splitter in the input modulation submodule and is transmitted into the output modulation submodule.

[0061] Step S4: The output modulation module polarizes the optical signal, selects modulation, and splits the signal into two beams for output.

[0062] Step S4.1: Perform polarization state filtering on the optical signals of the input and output modulation submodules, and select the modulation mode after polarization state filtering;

[0063] Step S4.2: The modulated optical signal enters the beam splitter and is split into two beams. The two beams are modulated separately. After the polarization state is completed, the modulation is selected and then output to the fourth and fifth ports.

[0064] The present invention also provides an on-chip sensitivity enhancement system for an interferometer, which can be implemented by executing the process steps of the on-chip sensitivity enhancement method for an interferometer. That is, those skilled in the art can understand the on-chip sensitivity enhancement method for an interferometer as a preferred embodiment of the on-chip sensitivity enhancement system for an interferometer.

[0065] Example 2:

[0066] The present invention also provides an on-chip sensitivity enhancement system for an interferometer, the system comprising the following modules:

[0067] Module M1: Input initial optical signal; the initial optical signal is incident from the first port, polarized by a polarizer with an optical axis angle of 45°, completing the pre-selection process. The pre-selection state is represented as: |H> and |V> represent horizontal polarization and vertical polarization, respectively.

[0068] Module M2: The input modulation submodule performs polarization state pre-selective modulation on the input initial optical signal and inputs it into the bias point modulation submodule;

[0069] Module M2.1: Filters the polarization state of the initial optical signal input from the first port and selects modulation before completing the polarization state selection;

[0070] Module M2.2: Introduces the optical signal into the beam splitter, splits the optical signal into beams, and inputs them to the bias point control submodule.

[0071] Module M3: The bias point modulation submodule splits the modulated optical signal into beams and performs phase modulation on the bias point of the optical signal at the waveguide branch.

[0072] Module M3.1: The optical signal from the input bias point control submodule is split into two optical signals, namely a horizontally polarized optical signal and a vertically polarized optical signal, through the Y-waveguide. The two optical signals enter the two waveguide arms of the Y branch respectively.

[0073] Module M3.2: By applying voltage to the electrodes on the Y branch, the polarization state of the optical signal on the branch is phase-modulated, the bias point is modulated, and the output is sent to the second port and the third port respectively;

[0074] Module M3.3: The optical signal is output from the second and third ports to the external interference module. This process is a weak coupling process, through which the physical quantity to be measured is coupled into the system. Afterward, the optical signal returns from the second and third ports and is combined at the Y waveguide. The combined optical signal enters the beam splitter in the input modulation submodule and is then transmitted into the output modulation submodule.

[0075] Module M4: The output modulation module polarizes the optical signal, selects modulation, and splits it into two beams of optical signal.

[0076] Module M4.1: Performs polarization state filtering on the optical signals from the input and output modulation submodules, and selects the modulation mode after polarization state filtering;

[0077] Module M4.2: The modulated optical signal enters the beam splitter and is split into two beams. The two beams are modulated separately. After the polarization state is completed, the modulation is selected and then output to the fourth and fifth ports.

[0078] Example 3:

[0079] To address the shortcomings of existing technologies, this invention utilizes the characteristic of weak measurement technology to amplify minute changes, providing an on-chip sensitivity enhancement module for interferometers to solve the problem of low phase sensitivity in existing interferometers.

[0080] According to the present invention, an on-chip sensitivity enhancement module for an interferometer is provided, comprising:

[0081] Input modulation submodule: used to perform polarization state preselection modulation on the input initial optical signal, complete the preselection process, and input the light into the bias point modulation submodule;

[0082] Bias point modulation submodule: used to polarize and split the signal light, and to perform phase modulation on the two polarized beams at the Y waveguide branch, thus completing the bias point modulation of the light;

[0083] Output modulation submodule: First, the signal light is filtered for polarization state, then the signal light is split and polarization state modulated. The whole process is a polarization state selection modulation process.

[0084] The input modulation submodule is used to perform polarization state pre-selective modulation on the input initial optical signal and input it into the bias point modulation submodule; the bias point modulation submodule is used to split the signal light into beams and perform phase modulation on the bias point of the signal light at the waveguide branch; the output modulation module is used to perform polarization state post-selective modulation on the signal light and split it into two beams of signal light.

[0085] Preferably, the input modulation submodule includes:

[0086] Step A1: Filter the polarization state of the initial signal light input from port 1 and select modulation before polarization state is completed;

[0087] Step A2: The signal light is then introduced into the beam splitter, which splits the light beam and inputs it to the bias point modulation submodule. This process will result in the loss of some signal light. The beam splitter can be replaced by a coupler (including but not limited to).

[0088] Preferably, the bias point modulation submodule includes:

[0089] Step B1: The signal light from the input bias point modulation submodule is split into two beams by the Y waveguide, namely horizontally polarized light and vertically polarized light, and the two beams enter the two waveguide arms of the Y branch respectively;

[0090] Step B2: The polarization state of the optical signal on the Y branch is phase-modulated by applying a voltage to the electrodes on the Y branch, that is, the bias point is modulated, and then output to port 2 and port 3 respectively.

[0091] Step B3: Light is output from ports 2 and 3 to external interference modules (including but not limited to fiber optic rings, mirrors, etc., which form Sagnac interference in the fiber optic ring and Michelson interference in the mirror). This process is a weak coupling process, through which the physical quantity to be measured is coupled into the system. After that, the light returns from ports 2 and 3 and is beamed at the Y waveguide. The beam-splittered light signal enters the beam splitter in the input modulation submodule and is transmitted into the output modulation submodule.

[0092] Preferably, the output modulation submodule includes:

[0093] Step C1: Select the polarization state of the signal light from the input and output modulation submodules, and then select the modulation (including but not limited to polarizer polarization, waveplate rotation, etc.).

[0094] Step C2: The modulated light then enters the beam splitter to split the beam, and the two split beams are modulated separately.

[0095] The process includes, but is not limited to, polarization detection, rotation, etc. After completing the polarization state, modulation is selected, and then the output is sent to ports 4 and 5.

[0096] According to the present invention, an on-chip sensitivity enhancement module for an interferometer is provided, such as... Figure 2 As shown, it includes:

[0097] The input modulation submodule is composed of polarizer (1) and beam splitter (2); the polarization beam splitter Y waveguide phase modulator is composed of bias point modulation submodule; beam splitter (4), mirror (5), polarizer (6) and polarizer (7) together constitute output modulation submodule.

[0098] Preferably, the input modulation submodule includes:

[0099] Step A1: The polarizer (1) polarizes the initial signal light input from port 1, completing the pre-polarization state selection modulation.

[0100] Step A2: Then the signal light is introduced into the beam splitter (2) to split the light beam and input it into the Y waveguide (3). This process will result in the loss of some signal light.

[0101] Step A3: The beam splitter (2) splits the light input from the bias point modulation submodule and inputs the light to the beam splitter (5).

[0102] Preferably, the bias point modulation submodule includes:

[0103] Step B1: The input signal light is split into two beams and enters the Y branch through the Y waveguide (3);

[0104] Step B2: Apply voltage to the electrodes on the Y branch to perform phase modulation on the two polarized light signals on the branch, that is, bias point modulation, and then output them to port 2 and port 3 respectively.

[0105] Step B3: Light is output from ports 2 and 3 to external interference modules (including but not limited to fiber optic rings, mirrors, etc., which enter the fiber optic ring to form Sagnac interference and enter the mirror to form Michelson interference); this process is a weak interaction, and the parameter to be measured acts into the system through this process; then the light returns from ports 2 and 3 and is combined at the Y waveguide to enter the beam splitter (2).

[0106] Preferably, the output modulation submodule includes:

[0107] Step C1: The beam splitter (4) splits the signal light into two beams, which enter the mirror (5) and the polarizer (6) respectively, and one beam enters the polarizer (7). After the signal light completes the polarization state through this process, it is selected for modulation. Then the two beams are output to the port (4) and the port (5).

[0108] Specifically, the working process of the on-chip sensitivity enhancement module for an interferometer provided by this invention is as follows:

[0109] Step 1: The light source is incident from port (1), and is polarized by polarizer (1). The optical axis angle of the polarizer is 45°, completing the pre-selection process. The pre-selection state is represented as: |H> and |V> represent horizontal polarization and vertical polarization, respectively;

[0110] Step 2: The signal light is then split by the beam splitter (2), the light intensity is reduced by 50%, and the signal light enters the polarization beam splitter Y waveguide phase modulator (3);

[0111] Step 3: The signal light enters the polarization-splitting Y-waveguide. The H-beam and V-beam separate and enter the Y branch, exiting from ports 2 and 3 to the external interference module (including but not limited to fiber rings, mirrors, etc.; entering the fiber ring forms a Sagnac interference, entering the mirror forms a Michelson interference). During this process, the H-beam and V-beam generate a certain phase difference (due to the different paths of the mirrors or the rotation of the fiber ring). This process is called weak interaction and can be represented as... System status description

[0112] Step 4: The two polarized beams return along their original paths after passing through the external interference module. When they pass through the Y-waveguide branch, a voltage is applied through the electrodes to change the phase difference between the two polarized beams, thereby adjusting the bias point of the system. After that, the H-beam and V-beam return along their original paths and are combined at the Y-waveguide.

[0113] Step 5: The signal light is split again by the beam splitter (2), the light intensity is reduced by 50%, and then enters the beam splitter (4);

[0114] Step 6: The two beams of light passing through the beam splitter (4) pass through the mirror (5) and polarizer (6), and the other beam passes through polarizer (7). The optical axis of polarizer (6) is at -45 + ε°, where ε is less than 1 degree, and the optical axis of polarizer (7) is at -45 - ε°, where ε is less than 1 degree. This process is the post-selection process, and the post-selection state is described as follows:

[0115] Step 7: After output modulation, the two optical signals are emitted from ports 4 and 5. I1 and I2 are obtained by detecting the light intensity of the emitted light signals from ports 4 and 5, and the light intensity contrast is defined. The parameter to be measured is calculated. The calculated sensitivity in the linear region is 4cotε; theoretically, the smaller ε is, the greater the sensitivity.

[0116] According to the present invention, an on-chip sensitivity enhancement module for an interferometer is provided, such as... Figure 3 As shown, the feature is that it includes:

[0117] The input modulation submodule includes: a polarizer (1) and a beam splitter (2);

[0118] The bias point modulation submodule includes: a polarization beam splitter Y-waveguide phase modulator (3);

[0119] The output modulation submodule includes: a quarter-wave plate (4), a polarizer (5), a beam splitter (6), a mirror (7), a high-pass filter (8), and a low-pass filter (9).

[0120] Preferably, the input modulation submodule includes:

[0121] Step A1: The polarizer (1) polarizes the initial optical signal input from port 1, completing the pre-polarization state selection modulation;

[0122] Step A2: The beam splitter (2) splits the modulated optical signal and transmits it into the Y waveguide (3);

[0123] Step A3: The beam splitter (2) splits the light input from the Y-waveguide modulation module and inputs the light into the quarter-wave plate (4).

[0124] Preferably, the bias point modulation submodule includes:

[0125] Step B1: The input signal light is polarized and split through the Y waveguide (3) and input to the Y branch;

[0126] Step B2: Apply voltage to the electrodes on the Y branch to perform phase modulation on the two polarized light signals on the branch, that is, bias point modulation, and then output them to port 2 and port 3 respectively.

[0127] Step B3: Light is output from ports 2 and 3 to external interference modules (including but not limited to fiber optic rings, mirrors, etc., which enter the fiber optic ring to form Sagnac interference and enter the mirror to form Michelson interference); this process is a weak interaction, and the physical quantity to be measured acts into the system through this process; then the light returns from ports 2 and 3 and is combined at the Y waveguide to enter the beam splitter (2).

[0128] Preferably, the output modulation submodule includes:

[0129] Step C1: After the signal light passes through a quarter-wave plate (4) and a polarizer (5) to complete the polarization state, the modulation process is selected;

[0130] Step C2: The beam splitter (6) splits the signal light into two beams. One beam of signal light passes through the mirror and enters the high-pass filter (8), while the other beam of signal light passes through the vertically polarized light and enters the low-pass filter (9).

[0131] Step C3: After the horizontally polarized light passes through the high-pass filter, part of the light is filtered out, and the remaining light is emitted from port 4; after the vertically polarized light passes through the low-pass filter, part of the light is filtered out, and the remaining light is emitted from port 5.

[0132] Specifically, the working process of the on-chip sensitivity enhancement module for an interferometer provided by this invention is as follows:

[0133] Step 1: The light source is incident from port (1). The light emitted by the light source has a Gaussian spectrum with a center wavelength of 1550nm. It is polarized by polarizer (1) with an optical axis angle of 45°, completing the pre-selection process. The pre-selection state is represented as: |H> and |V> represent horizontal polarization and vertical polarization, respectively;

[0134] Step 2: The signal light is then split by the beam splitter (2), the light intensity is reduced by 50%, and the signal light enters the polarization beam splitter Y waveguide phase modulator (3);

[0135] Step 3: The signal light enters the polarization-splitting Y-waveguide. The H-beam and V-beam separate and enter the Y branch, exiting from ports 2 and 3 to the external interference module (including but not limited to fiber rings, mirrors, etc.; entering the fiber ring forms a Sagnac interference, entering the mirror forms a Michelson interference). During this process, the H-beam and V-beam generate a certain phase difference (due to the different paths of the mirrors or the rotation of the fiber ring). This process is called weak interaction and can be represented as... System status description

[0136] Step 4: The two polarized beams return along their original paths after passing through the external interference module. When they pass through the Y-waveguide branch, a voltage is applied through the electrodes to change the phase difference between the two polarized beams, thereby adjusting the bias point of the system. Afterward, the H-beam and V-beam return along their original paths and are combined at the Y-waveguide.

[0137] Step 5: The signal light from the Y-waveguide is split again by the beam splitter (2), the light intensity is reduced by 50%, and it enters the quarter-wave plate (4);

[0138] Step 6: After the signal light passes through the quarter-wave plate (4) and polarizer (5), a selection process is completed. The optical axis angle of the quarter-wave plate (4) is -45°, and the optical axis angle of the polarizer (5) is -45° + 2ε, where 2ε is a small angle less than 1 degree. This process is the post-selection process, described as follows:

[0139] Step 7: After the signal light passes through the polarizer (5), it enters the beam splitter (7) and is split into two beams. One beam passes through the beam splitter (7) and enters the high-pass filter (8) to filter out light with a wavelength less than 1550nm. The other beam enters the low-pass filter (9) to filter out light with a wavelength greater than 1550nm. Then the two beams are emitted from ports 4 and 5 respectively.

[0140] The optical signal intensity at ports 4 and 5 is detected by a detector, and the optical spectrum offset is calculated. The desired parameter is then calculated from this offset (for an external fiber optic ring, the result is the change in angular velocity; for an external reflector, the result is the change in distance). Let I1 represent the intensity of the shorter wavelength light to the left of the output light spectrum, with the center wavelength of the light source at 1550 nm as the boundary; and let I2 represent the intensity of the longer wavelength light to the right of the output light spectrum, with the center wavelength of the light source at 1550 nm as the boundary. Subsequently, normalized difference operations were performed using a computer program. The parameters to be measured are calculated.

[0141] According to the present invention, an on-chip sensitivity enhancement module for an interferometer is provided, which operates on a Michelson interferometer, such as... Figure 4 As shown, it includes:

[0142] Input modulation submodule: used to perform polarization state preselection modulation on the input initial optical signal, complete the preselection process, and input the light into the bias point modulation submodule;

[0143] Bias point modulation submodule: used to polarize and split the signal light, and to perform phase modulation on the two polarized beams at the Y waveguide branch, thus completing the bias point modulation of the light;

[0144] Output modulation submodule: First, the signal light is filtered for polarization state, then the signal light is split and polarization state modulated. The whole process is a polarization state selection modulation process.

[0145] External interference module: consisting of a reflector (1) and a reflector (2), used to apply the physical quantity to be measured to the system.

[0146] Preferably, the input modulation submodule includes:

[0147] Step A1: The light source incident signal light from port 1, filters the polarization state of the initial signal light input from port 1, and completes the polarization state pre-selection modulation;

[0148] Step A2: The signal light is then introduced into the beam splitter, which splits the signal light and inputs it to the bias point modulation submodule. This process will result in the loss of some signal light. The beam splitter can be replaced by a coupler (including but not limited to).

[0149] Preferably, the bias point modulation submodule includes:

[0150] Step B1: The signal light from the input bias point modulation submodule is split into two beams by the Y waveguide, namely horizontally polarized light and vertically polarized light, and the two beams enter the two waveguide arms of the Y branch respectively;

[0151] Step B2: The polarization state of the optical signal on the Y branch is phase-modulated by applying a voltage to the electrodes on the Y branch, that is, the bias point is modulated, and then output to port 2 and port 3 respectively.

[0152] Step B3: After the light output from ports 2 and 3 completes the weak coupling process to the external interference module, the signal light returns from ports 2 and 3 and is combined at the Y waveguide. The combined light signal enters the beam splitter in the input modulation submodule and is then transmitted into the output modulation submodule.

[0153] Preferably, the external interference module includes:

[0154] Step C1: A beam of polarized light output from port 2 is incident on the reflector (1) as a polarization reference signal light and returns to port 2 along the same path;

[0155] Step C2: A beam of polarized light output from port 3 is incident on the reflector (2) as a signal light. By moving the reflector (2), the phase θ of the polarized signal light can be changed. The signal light is reflected back to port 3 after passing through the reflector (2).

[0156] Preferably, the output modulation submodule includes:

[0157] Step D1: The signal light input to the output modulation submodule is subjected to polarization state screening, and modulation is selected after polarization state screening (including but not limited to polarizer polarization, waveplate rotation, etc.);

[0158] Step D2: The modulated light then enters the beam splitter and is split into two beams. The two beams are modulated separately, including but not limited to polarization analysis, rotation, etc. After the polarization state is completed, the modulation is selected and then output to ports 4 and 5.

[0159] Specifically, the on-chip sensitivity enhancement module for interferometers provided by this invention operates as follows when used in a Michelson interferometer:

[0160] Step 1: The light source enters from port 1 and undergoes polarization state pre-selection modulation through the input modulation submodule;

[0161] Step 2: The signal light enters the bias point modulation submodule through the beam splitter. The bias point modulation submodule polarizes and splits the signal light and outputs it to port 2 and port 3.

[0162] Step 3: The polarized light emitted from port 2 is reflected by the mirror (1) and returns to port 2 along the same path to form the reference light;

[0163] Step 4: The polarized light emitted from port 3 is reflected by the reflector (2) and returns to port 3 along the same path. By moving the reflector (2), the optical path of the signal light can be changed to achieve the purpose of changing the phase θ. The change in optical path can be obtained by measuring the phase.

[0164] Step 5: The signal light reflected from ports 2 and 3 passes through the bias point control submodule, which performs phase modulation on the two polarized lights. After the two polarized lights are combined, they are input to the input modulation submodule. The input modulation submodule then inputs the returned optical signal to the output modulation submodule.

[0165] Step 6: The output modulation submodule polarizes the signal light and selects modulation, then splits it into beams and outputs them to port 4 and port 5.

[0166] According to the present invention, an on-chip sensitivity enhancement module for an interferometer is provided, which operates on a Sagnac interferometer, such as... Figure 5 As shown, it includes:

[0167] Input modulation submodule: used to perform polarization state preselection modulation on the input initial optical signal, complete the preselection process, and input the light into the bias point modulation submodule;

[0168] Bias point modulation submodule: used to polarize and split the signal light, and to perform phase modulation on the two polarized beams at the Y waveguide branch, thus completing the bias point modulation of the light;

[0169] Output modulation submodule: First, the signal light is filtered for polarization state, then the signal light is split and polarization state modulated. The whole process is a polarization state selection modulation process.

[0170] External interference module: consisting of an optical fiber ring (1), used to apply the physical quantity to be measured to the system.

[0171] Preferably, the input modulation submodule includes:

[0172] Step A1: The light source incident signal light from port 1, filters the polarization state of the initial signal light input from port 1, and completes the polarization state pre-selection modulation;

[0173] Step A2: The signal light is then introduced into the beam splitter, which splits the signal light and inputs it to the bias point modulation submodule. This process will result in the loss of some signal light. The beam splitter can be replaced by a coupler (including but not limited to).

[0174] Preferably, the bias point modulation submodule includes:

[0175] Step B1: The signal light from the input bias point modulation submodule is split into two beams by the Y waveguide, namely horizontally polarized light and vertically polarized light, and the two beams enter the two waveguide arms of the Y branch respectively;

[0176] Step B2: The polarization state of the optical signal on the Y branch is phase-modulated by applying a voltage to the electrodes on the Y branch, that is, the bias point is modulated, and then output to port 2 and port 3 respectively.

[0177] Step B3: After the light output from ports 2 and 3 completes the weak coupling process to the external interference module, the signal light returns from ports 2 and 3 and is combined at the Y waveguide. The combined light signal enters the beam splitter in the input modulation submodule and is then transmitted into the output modulation submodule.

[0178] Preferably, the external interference module includes:

[0179] Step C1: A beam of polarized light output from port 2 is incident on the fiber optic ring, passes through the fiber optic ring, and enters the bias point modulation submodule from port 3; A beam of polarized light output from port 3 is incident on the fiber optic ring, passes through the fiber optic ring, and enters the bias point modulation submodule from port 3.

[0180] Step C2: The physical quantity to be measured is introduced by rotating the fiber optic ring. The rotation of the fiber optic ring will cause the Sagnac effect, which will cause a phase difference between the two polarized beams.

[0181] Preferably, the output modulation submodule includes:

[0182] Step D1: The signal light input to the output modulation submodule is subjected to polarization state screening, and modulation is selected after polarization state screening (including but not limited to polarizer polarization, waveplate rotation, etc.);

[0183] Step D2: The modulated light then enters the beam splitter and is split into two beams. The two beams are modulated separately, including but not limited to polarization analysis, rotation, etc. After the polarization state is completed, the modulation is selected and then output to ports 4 and 5.

[0184] Specifically, the on-chip sensitivity enhancement module for interferometers provided by this invention operates as follows when used in a Sagnac interferometer:

[0185] Step 1: The light source enters from port 1 and undergoes polarization state pre-selection modulation through the input modulation submodule;

[0186] Step 2: The signal light enters the bias point modulation submodule through the beam splitter. The bias point modulation submodule polarizes and splits the signal light and outputs it to port 2 and port 3.

[0187] Step 3: A beam of polarized light output from port 2 is incident on the fiber optic ring, passes through the fiber optic ring, and enters the bias point modulation submodule from port 3; A beam of polarized light output from port 3 is incident on the fiber optic ring, passes through the fiber optic ring, and enters the bias point modulation submodule from port 3.

[0188] Step 4: The angular velocity of the physical quantity to be measured is introduced by rotating the fiber ring (1). The rotation of the fiber ring will cause the Sagnac effect, which will cause a phase difference between the two polarized beams. The rotational angular velocity can be calculated by measuring the phase difference.

[0189] Step 5: The signal light reflected from ports 2 and 3 passes through the bias point modulation submodule, which performs phase modulation on the two polarized lights. After the two polarized lights are combined, they are input to the input modulation submodule. The input modulation submodule then inputs the returned optical signal to the output modulation submodule.

[0190] Step 6: The output modulation submodule polarizes the signal light and selects modulation, then splits it into beams and outputs them to port 4 and port 5.

[0191] Those skilled in the art can understand this embodiment as a more specific description of Embodiment 1 and Embodiment 2.

[0192] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0193] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An on-chip sensitivity enhancement method for an interferometer, characterized in that, The method includes the following steps: Step S1: Input the initial optical signal; Step S2: The input modulation submodule performs polarization state pre-selective modulation on the input initial optical signal and inputs it into the bias point modulation submodule; Step S3: The bias point modulation submodule splits the modulated optical signal into beams and performs phase modulation on the bias point of the optical signal at the waveguide branch. Step S4: The output modulation module polarizes the optical signal, selects modulation, and splits the signal into two beams for output. Step S2 includes the following steps: Step S2.1: Filter the polarization state of the initial optical signal input at the first port and complete the polarization state pre-modulation selection; Step S2.2: Introduce the optical signal into the beam splitter, split the optical signal into beams, and input them into the bias point control submodule; Step S3 includes the following steps: Step S3.1: The optical signal from the input bias point control submodule is split into two optical signals, namely a horizontally polarized optical signal and a vertically polarized optical signal, through the Y waveguide. The two optical signals enter the two waveguide arms of the Y branch respectively. Step S3.2: Apply voltage to the electrodes on the Y branch to perform phase modulation of the polarization state of the optical signal on the branch, modulate the bias point, and output to the second port and the third port respectively; Step S3.3: The optical signal is output from the second port and the third port to the external interference module. This process is a weak coupling process, and the physical quantity to be measured is coupled into the system through this process. After that, the optical signal returns from the second port and the third port and is beamed at the Y waveguide. The beamed optical signal enters the beam splitter in the input modulation submodule and is transmitted into the output modulation submodule.

2. The on-chip sensitivity enhancement method for an interferometer according to claim 1, characterized in that, Step S4 includes the following steps: Step S4.1: Perform polarization state filtering on the optical signals of the input and output modulation submodules, and select the modulation mode after polarization state filtering; Step S4.2: The modulated optical signal enters the beam splitter and is split into two beams. The two beams are modulated separately. After the polarization state is completed, the modulation is selected and then output to the fourth and fifth ports.

3. The on-chip sensitivity enhancement method for an interferometer according to claim 1, characterized in that, In step S1: the initial optical signal is incident from the first port, polarized by a polarizer with an optical axis angle of 45°, completing the pre-selection process. The pre-selection state is represented as follows: , and These represent horizontal polarization and vertical polarization, respectively.

4. An on-chip sensitivity enhancement system for an interferometer, characterized in that, The system includes the following modules: Module M1: Input initial optical signal; Module M2: The input modulation submodule performs polarization state pre-selective modulation on the input initial optical signal and inputs it into the bias point modulation submodule; Module M3: The bias point modulation submodule splits the modulated optical signal into beams and performs phase modulation on the bias point of the optical signal at the waveguide branch. Module M4: The output modulation module polarizes the optical signal, selects modulation, and splits it into two beams of optical signal. Module M2 includes the following modules: Module M2.1: Filters the polarization state of the initial optical signal input from the first port and selects modulation before completing the polarization state selection; Module M2.2: Introduces the optical signal into the beam splitter, splits the optical signal, and inputs it to the bias point control submodule; Module M3 includes the following modules: Module M3.1: The optical signal from the input bias point control submodule is split into two optical signals, namely a horizontally polarized optical signal and a vertically polarized optical signal, through the Y-waveguide. The two optical signals enter the two waveguide arms of the Y branch respectively. Module M3.2: By applying voltage to the electrodes on the Y branch, the polarization state of the optical signal on the branch is phase-modulated, the bias point is modulated, and the output is sent to the second port and the third port respectively; Module M3.3: The optical signal is output from the second and third ports to the external interference module. This process is a weak coupling process, through which the physical quantity to be measured is coupled into the system. Afterward, the optical signal returns from the second and third ports and is combined at the Y waveguide. The combined optical signal enters the beam splitter in the input modulation submodule and is then transmitted into the output modulation submodule.

5. The on-chip sensitivity enhancement system for an interferometer according to claim 4, characterized in that, Module M4 includes the following modules: Module M4.1: Performs polarization state filtering on the optical signals from the input and output modulation submodules, and selects the modulation mode after polarization state filtering; Module M4.2: The modulated optical signal enters the beam splitter and is split into two beams. The two beams are modulated separately. After the polarization state is completed, the modulation is selected and then output to the fourth and fifth ports.

6. The on-chip sensitivity enhancement system for an interferometer according to claim 5, characterized in that, In module M1: the initial optical signal is incident from the first port, polarized by a polarizer with an optical axis angle of 45°, completing the pre-selection process. The pre-selection state is represented as follows: , and These represent horizontal polarization and vertical polarization, respectively.

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