Device for light attenuation
By using a variable attenuator drive unit and a stepper motor to rotate the optical attenuator wheel and switch the attenuation value, the problem of the optical attenuator being unadjustable is solved, the optical path structure is simplified, and the measurement efficiency and cost-effectiveness are improved.
Patent Information
- Application Number
- CN202520373248.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-05
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2035-03-05
AI Technical Summary
The attenuation values of existing optical power meters and optical energy meters are not adjustable, resulting in poor applicability. Furthermore, the wide-spectrum achromatic fiber coupling structure is complex and has low cost-effectiveness.
The system employs a variable attenuator drive unit, a stepper motor, a concave reflector, a reflector mounting bracket, an optical fiber mounting bracket, input and output optical fibers, and an optical attenuator wheel. The attenuation value is switched by rotating the optical attenuator wheel with the stepper motor, simplifying the optical path structure.
It achieves a wide range of optical attenuation adjustment, improves measurement efficiency and repeatability, simplifies the optical path structure, and enhances cost-effectiveness.
Smart Images
Figure CN223711869U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to optical instrument technical field especially relates to a device for light attenuation. BACKGROUND
[0002] Optical power meter and optical energy meter are the instruments of measuring light intensity, wherein the optical power meter measures the average power of light, and the energy meter measures the optical pulse energy, many instruments can measure the optical power and energy, and are called optical power and energy meter.
[0003] The current optical power meter and optical energy meter have the following technical problems:
[0004] Because the light attenuation value of the attenuator used for current measurement cannot be adjusted, the applicability is poor; replacing the attenuator with different light attenuation values leads to low measurement efficiency.
[0005] Because the light path structure of the wide-spectrum achromatic fiber coupling is relatively complex, the cost performance is poor. UTILITY MODEL CONTENT
[0006] The utility model provides a device for light attenuation, solves the technical problem that the light path structure is relatively complex and leads to poor cost performance.
[0007] To solve the above technical problems, the technical scheme adopted by the utility model is as follows:
[0008] A device for light attenuation, comprising a variable attenuator drive unit, a stepper motor, a concave mirror, a mirror fixing frame, a fiber fixing frame, an input optical fiber and an output optical fiber, and an optical attenuation piece rotating wheel, the concave mirror is fixedly connected with the mirror fixing frame, the input optical fiber and the output optical fiber are fixedly connected with the fiber fixing frame, and the optical attenuation piece rotating wheel is fixedly connected with the rotating shaft of the stepper motor; a plurality of optical attenuation pieces are arranged on the optical attenuation piece rotating wheel; the light outlet of the input optical fiber and the light inlet of the output optical fiber are located on the same side of the optical attenuation piece of the optical attenuation piece rotating wheel, the concave mirror is located on the other side of the optical attenuation piece of the optical attenuation piece rotating wheel, the light outlet of the input optical fiber is located on one side of the normal line of the concave mirror, the light inlet of the output optical fiber is located on the other side of the normal line of the concave mirror, and the output end of the variable attenuator drive unit is electrically connected with the stepper motor.
[0009] Further technical solutions are as follows: first to sixth rotating wheel holes are arranged on the optical attenuation piece rotating wheel, and the first to sixth rotating wheel holes are first rotating wheel hole, second rotating wheel hole, third rotating wheel hole, fourth rotating wheel hole, fifth rotating wheel hole and sixth rotating wheel hole, and the six rotating wheel holes are uniformly distributed on the optical attenuation piece rotating wheel.
[0010] Further technical solutions are as follows: no light attenuation sheet is fixed on the first rotating hole; a first light attenuation sheet is clamped and fixed on the second rotating hole to form a first group of light attenuation sheets; a first light attenuation sheet and a second light attenuation sheet are clamped and fixed on the third rotating hole to form a second group of light attenuation sheets; a first light attenuation sheet and a third light attenuation sheet are clamped and fixed on the fourth rotating hole to form a third group of light attenuation sheets; a first light attenuation sheet and a fourth light attenuation sheet are clamped and fixed on the fifth rotating hole to form a fourth group of light attenuation sheets; two first light attenuation sheets and a fourth light attenuation sheet are clamped and fixed on the sixth rotating hole to form a fifth group of light attenuation sheets.
[0011] Further technical solutions are as follows: the input optical fiber is used for connecting to be measured light; one end of the input optical fiber is connected with the input optical fiber interface; the other end of the input optical fiber is an output port; the output optical fiber is used for connecting to an input end of a single photon detector; one end of the output optical fiber is connected with the output optical fiber interface; the other end of the output optical fiber is an input port.
[0012] Further technical solutions are as follows: the concave mirror is coated with a reflecting film.
[0013] Further technical solutions are as follows: the device further comprises a box body, a motor side control port, an input optical fiber interface and an output optical fiber interface which are fixed on the box body; the variable attenuator driving unit, the stepping motor, the concave mirror, the mirror fixing frame, the optical fiber fixing frame, the input optical fiber and the output optical fiber are fixedly connected in the box body; the light attenuation sheet rotating wheel is located in the box body; one end of the input optical fiber is connected with the input optical fiber interface; the other end of the input optical fiber is an output port; one end of the output optical fiber is connected with the output optical fiber interface; the other end of the output optical fiber is an input port; the motor side control port is electrically connected with the control end of the variable attenuator driving unit.
[0014] The above technical solutions have the following beneficial effects:
[0015] The device for light attenuation comprises a variable attenuator driving unit, a stepping motor, a concave mirror, a mirror fixing frame, an optical fiber fixing frame, an input optical fiber and an output optical fiber and a light attenuation sheet rotating wheel; the concave mirror is fixedly connected with the mirror fixing frame; the input optical fiber and the output optical fiber are fixedly connected with the optical fiber fixing frame; the light attenuation sheet rotating wheel is fixedly connected with the rotating shaft of the stepping motor; a plurality of light attenuation sheets are arranged on the light attenuation sheet rotating wheel; the output port of the input optical fiber and the input port of the output optical fiber are located on the same side of the light attenuation sheets of the light attenuation sheet rotating wheel; the concave mirror is located on the other side of the light attenuation sheets of the light attenuation sheet rotating wheel; the output port of the input optical fiber is located on one side of the normal line of the concave mirror; the input port of the output optical fiber is located on the other side of the normal line of the concave mirror; the output end of the variable attenuator driving unit is electrically connected with the stepping motor. The device simplifies the optical path structure and improves the performance-cost ratio through the concave mirror.
[0016] In the measurement, there is always a rotating wheel hole in the light path, when the attenuation value needs to be adjusted, the rotating wheel of the light attenuation piece is rotated by the stepping motor, and any one set attenuation value can be switched to, so that a large range of light attenuation adjustment is realized, since the light attenuation piece of each rotating wheel hole is fixed, each adjustment is only switching between these fixed attenuation pieces, and extremely high repeatability can be obtained.
[0017] See the specific embodiment part for details. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1-1 is the first structure diagram of the application of the utility model;
[0019] Figure 1-2 is the structure diagram of the light attenuation piece rotating wheel in the utility model;
[0020] Figure 1-3 is the light path distribution diagram;
[0021] Figure 2 is the second structure diagram of the application of the utility model;
[0022] Figure 3 is the principle block diagram of the application of the utility model;
[0023] Figure 4 is the time sequence diagram of the data acquisition unit.
[0024] Among them: 1 light attenuation piece rotating wheel, 2-1 first rotating wheel hole, 2-2 second rotating wheel hole, 2-3 third rotating wheel hole, 2-4 fourth rotating wheel hole, 2-5 fifth rotating wheel hole, 2-6 sixth rotating wheel hole, 3 closed-loop control stepping motor, 4 concave mirror, 5 mirror fixing frame, 6 input optical fiber interface, 7 output optical fiber interface, 8 input optical fiber, 9 output optical fiber, 10 optical fiber fixing frame, 11 box body, 12 light attenuation piece, 13 rotating wheel type variable attenuator, 14 silicon avalanche photodiode single photon detector, 15 FPGA board card, 16 notebook computer, 17 cable, 18 data line, 19 rotating wheel motor control line, 20 light to be measured. DETAILED DESCRIPTION
[0025] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative, but not as any limitation on the application and its application or use. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.
[0026] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the application. However, the application can be practiced without the specific details described herein. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to unnecessarily obscure aspects of the application. Embodiments
[0027] As shown in Figure 1-1 The utility model discloses a device for light attenuation, including variable attenuator drive unit, closed loop control step motor 3, concave mirror 4, mirror fixed frame 5, optical fiber fixed frame 10, input optical fiber 8 and output optical fiber 9 and light attenuation piece rotating wheel 1, concave mirror 4 is fixedly connected with mirror fixed frame 5, and input optical fiber 8 and output optical fiber 9 are fixedly connected with optical fiber fixed frame 10, and light attenuation piece rotating wheel 1 is fixedly connected with the rotating shaft of closed loop control step motor 3.
[0028] The light attenuation device is a variable attenuator.
[0029] As shown in Figure 1-2 As shown in, six rotating wheel holes are evenly distributed on the light attenuation piece rotating wheel 1, and no light attenuation piece is fixed on the first rotating wheel hole 2-1, one first light attenuation piece is clamped and fixed on the second rotating wheel hole 2-2 to form a first group of light attenuation pieces, one first light attenuation piece and one second light attenuation piece are clamped and fixed on the third rotating wheel hole 2-3 to form a second group of light attenuation pieces, one first light attenuation piece and one third light attenuation piece are clamped and fixed on the fourth rotating wheel hole 2-4 to form a third group of light attenuation pieces, one first light attenuation piece and one fourth light attenuation piece are clamped and fixed on the fifth rotating wheel hole 2-5 to form a fourth group of light attenuation pieces, and two first light attenuation pieces and one fourth light attenuation piece are clamped and fixed on the sixth rotating wheel hole 2-6 to form a fifth group of light attenuation pieces.
[0030] The light attenuation pieces are installed in the six installation holes in the rotating wheel device.
[0031] As shown in Table 1, four kinds of light attenuation pieces are selected in the present application.
[0032] Table 1: Attenuation piece parameter table
[0033] Attenuation sheet number Type Operating wavelength nm Diameter mm Attenuation dB ① Absorbing 300-1100 25 10 ② Reflective 350-1100 25 10 ③ Reflective 350-1100 25 20 ④ Reflective 350-1100 25 30
[0034] As shown in Table 2, 0-3 light attenuation pieces are selected for each hole to form six attenuation values.
[0035] Table 2: Relationship table of rotating wheel hole serial number, attenuation value and transmittance
[0036] Rotary hole number Combination case Total attenuation value dB Total transmittance 1 Empty 0 1.0 2 ① 20 1.0 x 10 -2 ]]> 3 ①+② 40 1.0 x 10 -4 ]]> 4 ①+③ 60 1.0 x 10 -6 ]] 5 ①+④ 80 1.0 x 10 -8 ]] 6 ①+④+① 100 1.0 x 10 -10 ]]>
[0037] In the measurement, there is always a rotating hole in the light path, realizing the corresponding light attenuation. When the attenuation value needs to be adjusted, the rotating hole is switched to the nearby hole by rotating the light attenuation piece rotating wheel 1 driven by the stepping motor. According to the current attenuation value and the current stepping motor rotation angle position, the rotating angle can be adjusted to switch to any set attenuation value. A wide range of light attenuation adjustment can be realized, and since the light attenuation piece of each hole is fixed, each adjustment is only between these fixed attenuation pieces, which can obtain extremely high repeatability.
[0038] As shown in Figure 1-1 , in use, the variable attenuator driving unit, the closed-loop control stepping motor 3, the mirror fixing frame 5 and the optical fiber fixing frame 10 are all fixedly connected with the box body 11. One end of the input optical fiber 8 is connected with the input optical fiber interface 6, and the other end of the input optical fiber 8 is the light outlet. One end of the output optical fiber 9 is connected with the output optical fiber interface 7, and the other end of the output optical fiber 9 is the light inlet.
[0039] As shown in Figure 1-3 , the light outlet of the input optical fiber 8 and the light inlet of the output optical fiber 9 are located on the same side of the light attenuation piece 12 of the light attenuation piece rotating wheel 1, the concave mirror 4 is located on the other side of the light attenuation piece 12 of the light attenuation piece rotating wheel 1, the light outlet of the input optical fiber 8 is located on one side of the normal line of the concave mirror 4, and the light inlet of the output optical fiber 9 is located on the other side of the normal line of the concave mirror 4.
[0040] As shown in Figure 3 , in use, the measured light is connected with the input optical fiber interface of the variable attenuator through the input optical fiber, the output optical fiber interface of the variable attenuator is connected with the input end of the single-photon detector through the output optical fiber, the output end of the single-photon detector is electrically connected with the input end of the data acquisition unit through the cable, the output end of the data acquisition unit is electrically connected with the input end of the controller, the controller is electrically connected with the USB3.0 interface, the control end of the controller is electrically connected with the controller side control port, the controller side control port is electrically connected with the motor side control port of the variable attenuator through the control line. The motor side control port is electrically connected with the control end of the variable attenuator driving unit, and the output end of the variable attenuator driving unit is electrically connected with the stepping motor. The USB3.0 interface is connected with the computer through the data line.
[0041] The variable attenuator is described in detail as follows.
[0042] As shown in Figure 1-1 , the light path structure principle, the input optical fiber interface 6 and the input optical fiber 8 guide the measured light into the variable attenuator.
[0043] As shown in Figure 1-3As shown, the numerical aperture of the optical fiber determines the divergence angle of the light emitted from the end face of the optical fiber, the output light at the light outlet of the input optical fiber 8 propagates in a gradually diverging state, is irradiated to the concave mirror 4 through the light attenuation sheet 12, and after reflection, the light begins to propagate in a gradually converging state, then passes through the light attenuation sheet again, and finally converges to the light inlet of the output optical fiber 9. The light outlet of the input optical fiber 8 and the light inlet of the output optical fiber 9 are on both sides of the optical axis of the concave mirror 4, and the distance from the optical axis, i.e. the normal line, is 1 mm. The input optical fiber 8 adopts a multimode optical fiber with a core diameter of 105 μm, and the numerical aperture NA = 0.22; the output optical fiber 9 adopts a multimode optical fiber with a core diameter of 200 μm, and the numerical aperture NA = 0.22; the concave mirror 4 is selected to be a silver film, and the focal length f = 38.1 mm; the distance from the light outlet of the input optical fiber 8 and the light inlet of the output optical fiber 9 to the center front surface of the concave mirror 4 is 76.2 mm. The fiber-concave mirror-fiber composition is an imaging structure with a distance of 2f and an image distance of 2f, and compared with the traditional transmissive lens, the concave mirror 4 can realize wide-spectrum achromatic fiber coupling with only one device.
[0044] The single photon detector is a silicon avalanche photodiode single photon detector Si-SPAD, which is described in detail as follows.
[0045] The single photon detector is a kind of photoelectric detector capable of detecting single photons. Photons are the basic energy units of light, and the single photon detector outputs in the form of an electric pulse when detecting a photon. The Si-SPAD works in a continuous detection mode, has a wavelength response range of 400 nm to 1100 nm, a peak wavelength detection efficiency of ~65%, a dark count rate of ~200 cps (counts per second), and a saturation count rate of ~15 Mcps. When the maximum linear detection count rate is ≤10 Mcps, the nonlinear fitting coefficient β is ≤1.2.
[0046] The data acquisition unit and the controller based on the FPGA board 15 are described in detail as follows.
[0047] The controller is an xc7A-75T chip, and the data acquisition unit supports two working modes: a counter mode and a timer mode. The measurement method steps are the prior art.
[0048] As shown in Figure 4 In the counter mode, all the electric pulse signals output by the single photon detector SPAD are accumulated within the measurement time, and finally a total count value N of the measurement is obtained. In the timer mode, the time points of all the single photon detector SPAD output signals are recorded from the start time of the measurement as the starting point within the measurement time, and finally the time point information T1, T2, …,T n .
[0049] As shown in Figure 3As shown, the controller is responsible for communicating with the computer, uploading the collected data to the computer, and receiving control instructions from the computer to adjust the working parameters of the counter or timer, or control the attenuation value of the variable attenuator.
[0050] The program modules of the computer are known in the art, and are described in detail as follows.
[0051] The computer provides a human-machine interface, through which the user can control the operation of the ultra-high sensitivity optical power and energy meter USOM, process data, and output measurement results. The measurement results of continuous light include optical power and photon rate; the measurement results of pulsed light include single-pulse energy, average photon number per pulse, optical pulse width, and optical pulse repetition frequency. When the light to be measured is mixed light of pulsed light and continuous light, the measurement results of both types of light are output simultaneously.
[0052] As shown in Figure 2 The variable attenuator is a rotating wheel type variable attenuator 13, the single-photon detector is a silicon avalanche photodiode single-photon detector 14, the English abbreviation is Si-SPAD; the data acquisition unit, the controller, the USB 3.0 interface, and the controller side control port form an FPGA board card 15; the computer is a notebook computer 16; the optical signal: the light to be measured 20 is connected to the rotating wheel type variable attenuator 13 through the input optical fiber 8, and the attenuated light to be measured is guided into the silicon avalanche photodiode single-photon detector 14 by the output optical fiber 9 for detection. The electrical signal: the output signal of the silicon avalanche photodiode single-photon detector 14 is connected into the FPGA board card 15 by the cable 17, and the data collected by the FPGA board card 15 is uploaded to the notebook computer 16 by the USB data line 18. The control signal: the computer control instruction is downloaded to the FPGA board card 15 through the USB data line 18, then the FPGA board card 15 interprets the computer control instruction, and transmits the control signal to control the motor through the rotating wheel motor control line 19.
[0053] The application provides an optical measurement device, which is an ultra-high sensitivity optical power and energy meter USOM, and the features include:
[0054] (1) High sensitivity: compared with the traditional photodiode probe optical power and energy meter, the sensitivity of the application is improved by about five orders of magnitude.
[0055] (2) It has the function of measuring the pulse width of light.
[0056] (3) It has the function of measuring unknown light of mixed continuous light and pulsed light.
[0057] Compared with the above embodiment, the reflective film can also be used, and other wideband high-reflective films dous, such as other metal films: aluminum film, gold film, or wideband dielectric film.
[0058] Embodiment 2:
[0059] The embodiment 2 is different from the embodiment 1 in that a box, a motor side control port fixed on the box, an input optical fiber interface and an output optical fiber interface are further used, the variable attenuator drive unit, the stepping motor, the concave mirror, the mirror fixing frame, the optical fiber fixing frame, the input optical fiber and the output optical fiber are fixedly connected in the box, the light attenuating sheet rotating wheel is located in the box, one end of the input optical fiber is connected with the input optical fiber interface, the other end of the input optical fiber is an output port, one end of the output optical fiber is connected with the output optical fiber interface, and the other end of the output optical fiber is an input port; and the motor side control port is electrically connected with the control end of the variable attenuator drive unit.
[0060] As shown in Figure 1-1 The utility model discloses a device for light attenuation, including box 11, fixed on the box 11 motor side control port, input optical fiber interface 6 and output optical fiber interface 7, fixed in the box 11 variable attenuator drive unit, closed loop control stepping motor 3, concave mirror 4, mirror fixing frame 5, optical fiber fixing frame 10, input optical fiber 8 and output optical fiber 9 and be located in the light attenuating sheet rotating wheel 1 of box 11, variable attenuator drive unit, closed loop control stepping motor 3, mirror fixing frame 5 and optical fiber fixing frame 10 all are connected with the fixed connection of box 11, concave mirror 4 is connected with the fixed connection of mirror fixing frame 5, and input optical fiber 8 and output optical fiber 9 all are connected with the fixed connection of optical fiber fixing frame 10, and light attenuating sheet rotating wheel 1 is connected with the fixed connection of closed loop control stepping motor 3's rotating shaft.
[0061] The same is not repeated.
Claims
1. A device for optical attenuation, characterized in that: The system includes a variable attenuator drive unit, a stepper motor, a concave reflector (4), a reflector mounting bracket (5), an optical fiber mounting bracket (10), an input optical fiber (8), an output optical fiber (9), and an optical attenuator wheel (1). The concave reflector (4) is fixedly connected to the reflector mounting bracket (5), and the input optical fiber (8) and the output optical fiber (9) are both fixedly connected to the optical fiber mounting bracket (10). The optical attenuator wheel (1) is fixedly connected to the shaft of the stepper motor. Multiple optical attenuators are provided on the optical attenuator wheel (1). The light outlet of the input optical fiber (8) and the light inlet of the output optical fiber (9) are located on the same side of the optical attenuator on the optical attenuator wheel (1). The concave reflector (4) is located on the other side of the optical attenuator on the optical attenuator wheel (1). The light outlet of the input optical fiber (8) is located on one side of the normal of the concave reflector (4), and the light inlet of the output optical fiber (9) is located on the other side of the normal of the concave reflector (4). The output end of the variable attenuator drive unit is electrically connected to the stepper motor.
2. The device for optical attenuation according to claim 1, characterized in that: The optical attenuator wheel (1) has six rotating holes, namely the first rotating hole (2-1) to the sixth rotating hole (2-6), namely the first rotating hole (2-1), the second rotating hole (2-2), the third rotating hole (2-3), the fourth rotating hole (2-4), the fifth rotating hole (2-5), and the sixth rotating hole (2-6). The six rotating holes are evenly distributed on the optical attenuator wheel (1).
3. The device for optical attenuation according to claim 2, characterized in that: No optical attenuator is fixed in the first rotating wheel hole (2-1). A first optical attenuator is snapped and fixed in the second rotating wheel hole (2-2) to form a first group of optical attenuators. A first optical attenuator and a second optical attenuator are snapped and fixed in the third rotating wheel hole (2-3) to form a second group of optical attenuators. A first optical attenuator and a third optical attenuator are snapped and fixed in the fourth rotating wheel hole (2-4) to form a third group of optical attenuators. A first optical attenuator and a fourth optical attenuator are snapped and fixed in the fifth rotating wheel hole (2-5) to form a fourth group of optical attenuators. Two first optical attenuators and a fourth optical attenuator are snapped and fixed in the sixth rotating wheel hole (2-6) to form a fifth group of optical attenuators.
4. The device for optical attenuation according to claim 1, characterized in that: The input optical fiber (8) is used to connect the light to be tested. One end of the input optical fiber (8) is used to connect to the input optical fiber interface (6), and the other end of the input optical fiber (8) is the light output port. The output optical fiber (9) is used to connect to the input end of the single-photon detector. One end of the output optical fiber (9) is used to connect to the output optical fiber interface (7), and the other end of the output optical fiber (9) is the light input port.
5. The device for optical attenuation according to claim 1, characterized in that: The concave mirror (4) is coated with a reflective film.
6. The device for optical attenuation according to claim 1, characterized in that: It also includes a housing (11), a motor-side control port fixed on the housing (11), an input fiber optic interface (6), and an output fiber optic interface (7). The variable attenuator drive unit, stepper motor, concave reflector (4), reflector mounting bracket (5), fiber optic mounting bracket (10), input fiber (8), and output fiber (9) are all fixedly connected inside the housing (11). The optical attenuator wheel (1) is located inside the housing (11). One end of the input fiber (8) is connected to the input fiber optic interface (6), and the other end of the input fiber (8) is the light output port. One end of the output fiber (9) is connected to the output fiber optic interface (7), and the other end of the output fiber (9) is the light input port. The motor-side control port is electrically connected to the control terminal of the variable attenuator drive unit.