Ion trapping optical path polarization and power stability control device and method

Abstract

The invention discloses an ion trapping light path polarization and power stability control device and method, and solves the problem that the stability of the power and polarization of a trapping ion laser beam is insufficient. An ion trapping optical path polarization and power stability control device comprises a rotating mirror bracket, a first 1 / 2 wave plate, a sampling module and a feedback module. And the light path of the target light beam sequentially passes through the first 1 / 2 wave plate and the sampling module and then is emitted. The rotating mirror bracket is used for adjusting the polarization direction of the first 1 / 2 wave plate. The sampling module is used for collecting a polarization signal and a power signal of a target light beam and calculating a proportion signal of the polarization signal and the power signal. And the feedback module is used for receiving the proportion signal and sending a feedback result signal according to the proportion signal to adjust and rotate the spectacle frame. According to the invention, polarization and power feedback control is carried out on each light beam of trapping ions. The stability of ion fluorescence is improved.

Description

Technical Field

[0001] The present application relates to the technical field of optical frequency standards, and in particular to a device and method for stabilizing polarization and power of an ion-trapped optical path. Background Art

[0002] With the continuous development of frequency standard technology, the research on ion optical frequency standard technology using ions as quantum absorbers has become increasingly mature and the research is the most extensive. The ion trapped system is the most basic system for ion optical frequency standard. The stability of the ion fluorescence signal has an important influence on the judgment and measurement of various parameters in the whole clock closed-loop locking process. The stability of the power and polarization of the trapped ion laser beam plays a decisive role in the stability of the ion fluorescence signal intensity. Therefore, a method and device are needed to achieve the stability of the ion fluorescence signal by feedback control of the power and polarization of the laser entering the cavity. Summary of the invention

[0003] The embodiments of the present application provide a device and method for stabilizing polarization and power of an ion trapped optical path, which solves the problem of insufficient stability of the power and polarization of a trapped ion laser beam.

[0004] In a first aspect, an embodiment of the present application provides an ion trapping optical path polarization and power stabilization control device, comprising: a rotating mirror frame, a first 1 / 2 wave plate, a sampling module and a feedback module. The optical path of the target light beam passes through the first 1 / 2 wave plate and the sampling module in sequence and then emerges. The rotating mirror frame is used to adjust the polarization direction of the first 1 / 2 wave plate. The sampling module is used to collect the polarization signal and power signal of the target light beam and calculate the ratio signal of the two. The feedback module is used to receive the ratio signal and send a feedback result signal according to the ratio signal to adjust the rotating mirror frame.

[0005] In one embodiment, the sampling module comprises a polarization beam splitter, an optical power sampling plate, a polarization sampling photodetector and a power sampling photodetector. The target light beam passes through the polarization beam splitter and the power sampling plate in sequence. The polarization sampling photodetector or the power sampling photodetector collects polarization signals and power signals from the polarization beam splitter or the power sampling plate, respectively.

[0006] In one embodiment, it further comprises a front stage optical path and an optical power control optical path sequentially arranged between the light source and the first 1 / 2 wave plate. The front stage optical path is used for splitting and frequency locking the target light beam. The optical power control optical path is used for controlling the power of the target light beam.

[0007] In one embodiment, it further comprises an optical power control optical path arranged between the light source and the first 1 / 2 wave plate. The feedback module is connected to the optical power control optical path.

[0008] In one embodiment, a second 1 / 2 wave plate is further included. The second 1 / 2 wave plate is arranged at the exit.

[0009] In a second aspect, the present application also provides a method for stabilizing polarization and power of an ion trapped optical path, using the ion trapped optical path polarization and power stabilization control device described in any one of the embodiments of the first aspect, comprising the steps of: Obtain the target light beam and adjust the light beam polarization to P polarized light; The target light beam is polarized and split, and the reflected light of the polarized beam is polarized and sampled to obtain a polarization signal; the transmitted light of the polarized beam is power sampled to obtain a power signal; Comparing the polarization signal and the power signal to obtain a proportional signal, and performing operations on the proportional signal to obtain a first feedback result signal; The rotating mirror frame is adjusted according to the first feedback result signal.

[0010] In one of the embodiments, the method further comprises the steps of: splitting the target light beam, frequency locking, and power controlling.

[0011] In one embodiment, obtaining the power signal further includes the steps of: performing calculations based on the power signal to obtain a second feedback result signal; and adjusting the power of the target light beam based on the second feedback result signal.

[0012] In one of the embodiments, the transmitted light after power sampling further comprises the step of: adjusting the polarization of the transmitted light so that the radiation generated by the transmitted light after the outgoing polarization enters the vacuum chamber and interacts with ions is within a set range.

[0013] In one of the embodiments, in response to the continuous transmission of laser light between the light source and the vacuum chamber, the first feedback result signal continuously adjusts the rotating mirror frame.

[0014] At least one of the above technical solutions adopted in the embodiments of the present application can achieve the following beneficial effects: The present application can perform feedback control of polarization and power of each light beam of trapped ions by simply sampling the ion trapping optical path through feedback loops and common optomechanical components. In a limited space volume, ion trapping light with stable polarization and power can be obtained, thereby improving the stability of ion fluorescence. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 The structure diagram of the ion trapping optical path polarization and power stabilization control device proposed in this application Figure 2 This is a flow chart of a method for stabilizing polarization and power of an ion trapping optical path proposed in this application.

[0016] Figure 3 This is a flow chart of the ion trapping optical path polarization and power stabilization control system proposed in this application. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0018] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0019] Figure 1 This is a structural diagram of an ion trapping optical path polarization and power stabilization control device proposed in this application, comprising: a rotating mirror frame, a first 1 / 2 wave plate 1, a sampling module 2 and a feedback module 3.

[0020] The optical path of the target light beam passes through the first 1 / 2 wave plate and the sampling module in sequence and then emerges.

[0021] For example, the target beam for trapping ions is coupled into the optical fiber through the optical fiber coupling head 4, and is introduced into the vicinity of the vacuum chamber where the ions are located by the optical fiber. The target beam is collimated by the optical fiber collimating head 5 and then output.

[0022] The rotating mirror frame is used to adjust the polarization direction of the first 1 / 2 wave plate.

[0023] For example, the rotating mirror frame is a pressure-controlled rotating mirror frame.

[0024] For example, the target light beam first passes through a 1 / 2 wave plate mounted on a voltage-controlled rotating mirror frame to adjust the polarization of the light beam so that the light beam is polarized into P polarized light, that is, the polarization direction is the same as the polarization direction of the transmitted light of the polarization beam splitter.

[0025] The sampling module is used to collect the polarization signal and the power signal of the target light beam and calculate the ratio signal of the two.

[0026] In one embodiment, the sampling module includes a polarization beam splitter 21 , an optical power sampling plate 22 , a polarization sampling photodetector 23 and a power sampling photodetector 24 .

[0027] The target light beam passes through a polarization beam splitter and a power sampling plate in sequence.

[0028] The polarization sampling photodetector or the power sampling photodetector collects polarization signals and power signals from the polarization beam splitter or the power sampling plate, respectively.

[0029] For example, the target beam passes through a polarization beam splitter, which may be a polarization beam splitter cube (PBS). The reflected light of the PBS is taken as polarization sampling light of the target beam. The polarization sampling light is collected by a polarization sampling photodetector to obtain a polarization signal.

[0030] After polarization sampling, the transmitted light beam of the PBS passes through the power sampling sheet, and the sampling light is collected by the power sampling photodetector to obtain a power signal.

[0031] For example, a proportional operation is performed on the polarization signal and the power signal to obtain a proportional signal of the polarization direction of the reflected light.

[0032] The feedback module is used to receive the proportional signal and send a feedback result signal according to the proportional signal to adjust the rotating mirror frame.

[0033] The feedback module receives the proportional signal, performs a proportional integral (PI) locking operation on the error signal according to the obtained proportional signal and the preset proportional signal, and obtains a feedback signal. The feedback signal is sent to adjust the rotating mirror frame to change the polarization direction of the target light beam.

[0034] For example, the proportional signal is operated through a feedback module, and the obtained feedback result signal is input into a voltage-controlled rotating mirror frame to adjust the polarization direction of the optical path.

[0035] In one embodiment, it further comprises a front-stage optical path 6 and an optical power control optical path 7 which are sequentially arranged between the light source and the first 1 / 2 wave plate.

[0036] The front-stage optical path is used for splitting and frequency locking the target light beam.

[0037] The optical power control optical path is used to control the power of the target light beam.

[0038] For example, after the target light beam for trapping ions is emitted from the laser, it passes through the optical path for plasma trapping front stage and the optical power control path of splitting, frequency locking, and power control, and then enters the optical fiber coupling head.

[0039] In one embodiment, it further comprises an optical power control optical path arranged between the light source and the first 1 / 2 wave plate. The feedback module is connected to the optical power control optical path.

[0040] For example, the detection signal of the power sampling photodetector is input into the power feedback module separately, and the obtained feedback result signal is input into the optical power control optical path in the front optical path to adjust the power of the ion trapping beam.

[0041] In one embodiment, it further comprises a second 1 / 2 wave plate 8. The second 1 / 2 wave plate is arranged at the exit.

[0042] For example, after polarization and power stabilization, the light beam is rotated to the required polarization direction through a 1 / 2 wave plate and enters the vacuum chamber to interact with ions.

[0043] Figure 2 This is a flow chart of a method for stabilizing polarization and power of an ion trapped optical path proposed in the present application, using the ion trapped optical path polarization and power stabilization control device described in any one of the embodiments of the first aspect, comprising the steps of: Step 210, obtaining a target light beam, and adjusting the light beam polarization to P polarized light; Step 220, performing polarization splitting on the target light beam, performing polarization sampling on the reflected light of the polarization splitting to obtain a polarization signal; performing power sampling on the transmitted light of the polarization splitting to obtain a power signal; In one embodiment, in step 220, obtaining the power signal further comprises the steps of: Step 220-1, performing calculation according to the power signal to obtain a second feedback result signal; Step 220 - 2 : adjusting the power of the target light beam according to the second feedback result signal.

[0044] Step 230: Compare the polarization signal and the power signal to obtain a proportional signal, and perform calculations on the proportional signal to obtain a first feedback result signal; The method for calculating the proportional signal specifically includes the following steps: determining a preset proportional signal; Obtaining an error signal according to the obtained proportional signal and a preset proportional signal; The error signal is subjected to proportional integral (PI) locking operation to obtain a feedback signal.

[0045] In one embodiment, in step 240, the transmitted light subjected to power sampling further comprises the steps of: adjusting polarization of the transmitted light; The polarized transmitted light enters the vacuum chamber and interacts with ions.

[0046] After polarization and power stabilization, the light beam is rotated to the required polarization direction through a 1 / 2 wave plate and enters the vacuum chamber to interact with ions.

[0047] Step 240: Adjust the rotating mirror frame according to the first feedback result signal.

[0048] In one embodiment, before step 210, the process further includes the following steps: Step 200: split the target light beam, lock the frequency, and control the power.

[0049] For example, after the target light beam for trapping ions is emitted from the laser, it goes through the pre-stage optical path of plasma trapping, such as light splitting, frequency locking, and power control.

[0050] In one of the embodiments, in response to the continuous transmission of laser light between the light source and the vacuum chamber, the first feedback result signal continuously adjusts the rotating mirror frame.

[0051] The optical fiber used to transmit laser light between the light source and the vacuum cavity changes its polarization characteristics due to environmental factors. The above adjustments are performed in real time to maintain a constant optical power input to the vacuum cavity and a constant proportion of polarized light in a specific polarization direction.

[0052] The flow chart of the beam stabilization control system is as follows Figure 3 As shown: After the trapped ion light is emitted from the laser, it passes through the pre-stage optical path of the plasma cooling light after splitting, frequency locking, and power control, and then is emitted through the ion cooling beam coupling head. The light beam first passes through the 1 / 2 wave plate mounted on the voltage-controlled rotating mirror frame to adjust the polarization of the light beam so that the light beam is polarized to P polarized light, that is, the polarization direction is the same as the polarization direction of the transmitted light of the polarization beam splitter. Then the light beam passes through the polarization beam splitter cube (PBS), and the reflected light of the PBS is taken as the polarization sampling light of the light beam to obtain the polarization signal. After polarization sampling, the light beam passes through the power sampling plate to obtain the power signal. The polarization signal and the power signal are proportionally calculated to obtain the proportional signal of the polarization direction of the reflected light. The proportional signal is calculated through the feedback module, and the feedback result signal obtained is input into the voltage-controlled rotating mirror frame to adjust the polarization direction of the optical path.

[0053] At the same time, the detection signal of the power sampling photoelectric detector is input into the power feedback module separately, and the obtained feedback result signal is input into the optical power control optical path module in the front optical path to adjust the power of the ion trapping light beam.

[0054] After polarization and power stabilization, the light beam is rotated to the required polarization direction through a 1 / 2 wave plate and enters the vacuum chamber to interact with ions.

[0055] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0056] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0057] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. An ion trapping optical path polarization and power stability control device, characterized in that: Contains: rotating mirror frame, first 1 / 2 wave plate, sampling module and feedback module; The optical path of the target light beam passes through the first 1 / 2 wave plate and the sampling module in sequence and then emerges; The rotating mirror frame is used to adjust the polarization direction of the first 1 / 2 wave plate; The sampling module is used to collect the polarization signal and power signal of the target light beam and calculate the ratio signal of the two; The feedback module is used to receive the proportional signal and send a feedback result signal according to the proportional signal to adjust the rotating mirror frame.

2. The ion trapping optical path polarization and power stabilization control device according to claim 1, characterized in that: The sampling module includes a polarization beam splitter, an optical power sampling plate, a polarization sampling photodetector and a power sampling photodetector; The target light beam passes through the polarization beam splitter and the power sampling plate in sequence; The polarization sampling photodetector or the power sampling photodetector collects polarization signals and power signals from the polarization beam splitter or the power sampling plate, respectively.

3. The ion trapping optical path polarization and power stabilization control device according to claim 1, characterized in that: It also includes a front-stage optical path and an optical power control optical path which are sequentially arranged between the light source and the first 1 / 2 wave plate; The front-stage optical path is used for splitting and frequency locking the target light beam; The optical power control optical path is used to control the target light beam power.

4. The ion trapping optical path polarization and power stabilization control device according to claim 1, characterized in that: It also includes an optical power control optical path arranged between the light source and the first 1 / 2 wave plate; The feedback module is connected to the optical power control optical path.

5. The ion trapping optical path polarization and power stabilization control device according to claim 1, characterized in that: Also includes a second 1 / 2 wave plate; The second 1 / 2 wave plate is arranged at the exit.

6. A method for stabilizing polarization and power of an ion trapping optical path, characterized in that: The device for controlling polarization and power stability of an ion trapped optical path according to any one of claims 1 to 5 comprises the following steps: Obtain the target light beam and adjust the light beam polarization to P polarized light; The target light beam is polarized and split, and the reflected light of the polarized beam is polarized and sampled to obtain a polarization signal; the transmitted light of the polarized beam is power sampled to obtain a power signal; Comparing the polarization signal and the power signal to obtain a proportional signal, and performing operations on the proportional signal to obtain a first feedback result signal; The rotating mirror frame is adjusted according to the first feedback result signal.

7. The method for controlling polarization and power stability of an ion trapped optical path according to claim 6, characterized in that: Before the target beam is emitted and passes through the first 1 / 2 wave plate, the following steps are also included: Split, frequency lock and power control the target beam.

8. The method for controlling polarization and power stability of an ion trapping optical path according to claim 6, characterized in that: Obtaining the power signal also includes the following steps: Performing calculation according to the power signal to obtain a second feedback result signal; The power of the target light beam is adjusted according to the second feedback result signal.

9. The method for controlling polarization and power stability of an ion trapped optical path according to claim 6, characterized in that: The transmitted light after power sampling further comprises the steps of: The polarization of the transmitted light is adjusted so that the radiation generated by the transmitted light after the outgoing polarization enters the vacuum chamber and interacts with the ions is within a set range.

10. The method for controlling polarization and power stability of an ion trapping optical path according to claim 6, characterized in that: In response to the continuous transmission of laser light between the light source and the vacuum chamber, the first feedback result signal continuously adjusts the rotating mirror frame.

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