Device and method for measuring optical performance of fluorescence conversion crystal

Abstract

The invention discloses a device and a method for measuring the optical performance of a fluorescence conversion crystal, and the device comprises a laser, a sample bearing box, an optical fiber probe, a spectrometer, a silicon photodiode, an acquisition card and a computer, and the sample bearing box can be connected with the optical fiber probe or the silicon photodiode. The spectrum information, the afterglow attenuation characteristics, the conversion efficiency and the conversion efficiency uniformity information are acquired through a spectrograph or an acquisition card, and finally the emission spectrum, the afterglow attenuation characteristics, the conversion efficiency and the conversion efficiency uniformity are obtained through computer processing. Performance indexes collected by the device are complete, a complete crystal quality evaluation system can be constructed, and a complete and reliable reference is provided for screening of conversion crystals. And the sample to be measured is arranged in the sample bearing box with the closed periphery, so that the interference of ambient light can be effectively resisted, and the accuracy of performance measurement is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of precision measurement, and particularly relates to a measuring device and a measuring method for the optical properties of a fluorescence conversion crystal. Background Art

[0002] In the field of deep ultraviolet lithography machines, accurately measuring the single-pulse energy of deep ultraviolet lasers is crucial. To achieve this goal, fluorescence conversion crystals such as sapphire and Ce:YAG are often used to convert high-repetition-rate deep ultraviolet lasers into visible or near-infrared fluorescence, and then precision measurement is carried out through silicon-based photodetectors such as PDs. The performance parameters of these fluorescence conversion crystals, such as spectrum, afterglow, conversion efficiency, and uniformity, have a decisive impact on the key performance parameters of deep ultraviolet laser energy detectors, such as reproducibility, energy linearity, and stability. Before manufacturing a deep ultraviolet laser energy detector, in order to ensure the performance of the detector, it is necessary to accurately measure the above performance indicators of the fluorescence conversion crystal and guide the screening of the fluorescence conversion crystal according to the measurement results.

[0003] CN106770140A discloses a measuring device and a measuring method for the up-conversion luminescence characteristics of a crystal. The device includes an excitation optical path, a sample stage, a spectrometer, and a computer; the sample stage is in a disc shape and can rotate around its own central axis under the drive of a driving device. At least two sample positions for placing samples are provided on the sample stage, and each sample position is evenly distributed on the sample stage and located on the same circle with the center of the sample stage as the center of the circle; the excitation optical path includes a laser, a polarizer, and a lens. The emitted laser of the laser passes through the center of the polarizer and is perpendicularly irradiated on the center of the lens, so as to be focused on one of the samples on the sample stage. Although this device can measure the emission spectrum of the fluorescence conversion crystal and has a high measurement efficiency, it cannot measure other key performance indicators (such as conversion efficiency uniformity, afterglow decay characteristics, etc.), and the measured performance indicators are few, and it cannot provide a complete and reliable reference for the screening of the fluorescence conversion crystal; moreover, the fluorescence collection efficiency of this device is low, and there are often problems of inaccurate measurement for the measurement of fluorescence crystals with low conversion efficiency; in addition, the samples of this device are directly exposed to the air, and the anti-environmental light interference ability is poor, further reducing the accuracy of performance measurement. Summary of the Invention

[0004] Aiming at the above deficiencies existing in the prior art, the purpose of the present invention is to provide a measuring device and a measuring method for the optical properties of a fluorescence conversion crystal, so as to solve the problems that the existing device measures fewer performance indicators, cannot construct a complete crystal quality evaluation system, and has a low fluorescence collection efficiency and poor anti-environmental light interference ability, resulting in inaccurate performance measurement.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0006] A measuring device for the optical properties of a fluorescence conversion crystal, comprising a laser and a computer, and further comprising a sample carrier box,

[0007] A sample accommodation cavity is formed in the middle of the sample carrier box, and the sample accommodation cavity penetrates through the top of the sample carrier box for placing a sample to be measured; an incident hole is formed on one side of the sample carrier box, and a first exit hole and a second exit hole are arranged on the other side opposite thereto. All the exit holes are communicated with the incident hole, and the center line of the first exit hole and the center line of the incident hole are on the same axis; during operation, the laser emitted by the laser can enter through the incident hole and irradiate on the sample to be measured;

[0008] A signal detection device is installed in the second exit hole. The signal detection device is a fiber optic probe and a silicon photodiode, and the fiber optic probe and the silicon photodiode are alternatively installed in the second exit hole; when the signal detection device is a fiber optic probe, the fiber optic probe is connected to a spectrometer through a wire, and the spectrometer is connected to a computer through a wire; when the signal detection device is a silicon photodiode, the silicon photodiode is connected to a data acquisition card through a wire, and the data acquisition card is connected to a computer through a wire.

[0009] Further, rubber wheels are arranged at the bottom of the sample accommodation cavity, and the rubber wheels are driven by a motor arranged outside the sample carrier box to realize rotation; the sample to be measured is circular, and the bottom of the sample to be measured just tangentially contacts the top of the rubber wheels, and the sample to be measured is driven to rotate by the rotation of the rubber wheels.

[0010] Further, two auxiliary rollers are symmetrically arranged in the sample accommodation cavity. The two auxiliary rollers and the rubber wheels are used to jointly support the circumferential surface of the sample to be measured so that it is suspended in the sample accommodation cavity.

[0011] Further, a reflective film is uniformly coated on the inner wall of the sample accommodation cavity.

[0012] Further, a light-shielding cover matching the sample carrier box is arranged on the sample carrier box, and three through holes are formed in the light-shielding cover, which are respectively opposite to the incident hole, the first exit hole and the second exit hole of the sample carrier box.

[0013] Further, a lifting rod is arranged at the bottom of the sample carrier box.

[0014] Further, the distance between the incident hole and the second exit hole is 10 - 30 mm.

[0015] A method for measuring the optical properties of a fluorescence conversion crystal, using the above device for measurement, comprising the following steps:

[0016] A. Place the sample carrier box on the light path of the laser output. Turn on the laser, adjust the position of the sample carrier box and the size of the laser spot so that the laser emitted by the laser can just enter through the incident hole;

[0017] B. Turn off the laser and place the sample to be measured in the sample carrier box;

[0018] C. When measuring the emission spectrum, install the optical fiber probe in the second exit hole; turn on the laser, collect the information collected by the optical fiber probe through the spectrometer, and process the information collected by the spectrometer through the computer to obtain the emission spectrum;

[0019] When measuring the afterglow, turn on the laser, install the silicon photodiode in the second exit hole; collect the information collected by the silicon photodiode through the acquisition card, and process the information collected by the acquisition card through the computer to obtain the afterglow decay characteristics;

[0020] When measuring the conversion efficiency and conversion efficiency uniformity, install the silicon photodiode in the second exit hole; turn on the laser, collect the information collected by the silicon photodiode through the acquisition card, and process the information collected by the acquisition card through the computer to obtain the single measurement conversion efficiency. After each measurement, rotate the sample to be measured, measure the conversion efficiency at different positions of the sample to be measured, and process it through the computer to obtain the average conversion efficiency and conversion efficiency uniformity.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention provides a measuring device for the optical properties of a fluorescence conversion crystal. The sample carrier box can be connected to an optical fiber probe or a silicon photodiode, and the spectral information, afterglow decay characteristics, conversion efficiency, and conversion efficiency uniformity information can be collected through a spectrometer or an acquisition card, and finally the emission spectrum, afterglow decay characteristics, conversion efficiency, and conversion efficiency uniformity can be obtained through computer processing. The performance indicators collected by the device of the present invention are complete, which is beneficial to constructing a complete crystal quality evaluation system and providing a complete and reliable reference for the screening of conversion crystals. Moreover, the sample to be measured in the present invention is placed in a sample carrier box with a closed perimeter, which can effectively resist the interference of ambient light and improve the accuracy of performance measurement.

[0023] 2. When measuring the conversion efficiency uniformity of the present invention, the rubber wheels at the bottom of the sample carrier box can be driven by a motor, and the sample to be measured can be driven to rotate slowly through the friction between the rubber wheels and the sample to be measured, so as to measure the optical properties at different positions of the sample to be measured and further realize the measurement of the conversion efficiency uniformity of the fluorescence crystal. The design of this device structure can avoid manually rotating the sample, reduce manual operation, save labor costs, and realize the automatic measurement of the conversion efficiency uniformity.

[0024] 3. The sample carrier box provided by the present invention is also provided with a reflective film, which can enhance the fluorescence reflection probability, effectively improve the light output rate of the fluorescence conversion crystal, thereby improving the accuracy of crystal performance measurement. In particular, it has a significant effect on improving the performance accuracy of measuring low-fluorescence conversion crystals, solving the pain point of difficult accurate measurement of the performance of low-fluorescence conversion crystals. The present invention also provides a light-shielding cover that can further resist ambient light interference, thereby improving the accuracy of the performance of the fluorescence conversion crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic cross-sectional structure diagram of the sample carrier box in the measuring device for the optical performance of the fluorescence conversion crystal of the present invention;

[0026] Figure 2 is an enlarged schematic diagram of the relative positions of the sample to be measured, the rubber wheel, and the auxiliary roller in the sample carrier box of the present invention;

[0027] Figure 3 is a schematic diagram of the overall structure of the sample carrier box of the present invention;

[0028] Figure 4 is a schematic diagram of the device usage when measuring the emission spectrum of the present invention;

[0029] Figure 5 is a schematic diagram of the device usage when measuring the afterglow, conversion efficiency, and conversion efficiency uniformity of the present invention.

[0030] In the figure, laser 1, sample carrier box 2, optical fiber probe 3, spectrometer 4, computer 5, incident hole 6, first exit hole 7, second exit hole 8, sample accommodation cavity 9, sample to be measured 10, silicon photodiode 11, acquisition card 12, rubber wheel 13, motor 14, auxiliary roller 15, light-shielding cover 16, lifting rod 17. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The following combines specific embodiments to further describe in detail the specific implementation manners of the present invention.

[0032] Embodiment

[0033] As Figure 1 、 Figure 2 、 Figure 3As shown in the figure, the present invention provides a measuring device for the optical properties of a fluorescence conversion crystal, including a laser 1, a sample carrier box 2, and a computer 5. A sample accommodation cavity 9 is provided in the middle of the sample carrier box 2. The sample accommodation cavity 9 penetrates through the top of the sample carrier box 2 and is used to place a sample to be measured 10. An incident hole 6 is provided on one side of the sample carrier box 2, and a first exit hole 7 and a second exit hole 8 are provided on the other side opposite thereto. All the exit holes are communicated with the incident hole 6, and the center line of the first exit hole 7 and the center line of the incident hole 6 are on the same axis. During operation, the laser emitted by the laser 1 can enter through the incident hole 6 and irradiate the sample to be measured 10.

[0034] A signal detection device is installed in the second exit hole 8. The signal detection device is an optical fiber probe 3 and a silicon photodiode 11, and the optical fiber probe 3 and the silicon photodiode 11 are alternatively installed in the second exit hole 8. When the signal detection device is the optical fiber probe 3, the optical fiber probe 3 is connected to a spectrometer 4 through a wire, and the spectrometer 4 is connected to a computer 5 through a wire. When the signal detection device is the silicon photodiode 11, the silicon photodiode 11 is connected to a data acquisition card 12 through a wire, and the data acquisition card 12 is connected to a computer 5 through a wire.

[0035] During specific implementation, a rubber wheel 13 is provided at the bottom of the sample accommodation cavity 9. The rubber wheel 13 is driven by a motor 14 provided outside the sample carrier box 2 to rotate. The sample to be measured 10 is circular, and the bottom of the sample to be measured 10 just touches the top of the rubber wheel 13. The rotation of the rubber wheel 13 drives the sample to be measured 10 to rotate. By providing the motor 14 and the rubber wheel 13, the sample to be measured 10 can be driven to rotate by friction, so as to automatically measure the optical properties of different positions of the sample to be measured 10. In this way, when measuring the crystal uniformity, manual rotation of the sample can be avoided repeatedly, manual operation can be reduced, and labor costs can be saved.

[0036] During specific implementation, two auxiliary rollers 15 are symmetrically arranged in the sample accommodation cavity 9. The two auxiliary rollers 15 and the rubber wheel 13 jointly support the circumferential surface of the sample to be measured 10 so that it is suspended in the sample accommodation cavity 9. In this way, the two auxiliary rollers 15 can not only fix the crystal but also assist the sample to rotate, realizing automatic measurement of the optical properties of different positions of the sample.

[0037] During specific implementation, a reflective film (not shown) is uniformly coated on the inner wall of the sample accommodation cavity 9. During specific implementation, the reflective film is an ESR film, or it can also be other high-reflective films. The setting of the reflective film can enhance the fluorescence reflection probability and improve the light output rate of the fluorescence conversion crystal, thereby improving the accuracy of crystal performance measurement. It has a significant effect on improving the performance measurement accuracy of low-fluorescence conversion crystals in particular, and solves the pain point of difficult accurate measurement of the performance of low-fluorescence conversion crystals.

[0038] In specific implementation, a light-shielding cover 16 matching the sample carrier box 2 is provided. Three through holes are formed in the light-shielding cover 16, which are respectively aligned with the incident hole 6, the first exit hole 7, and the second exit hole 8 of the sample carrier box 2. In this way, the interference of ambient light can be further reduced, and the accuracy of the measurement result can be improved.

[0039] In specific implementation, a lifting rod 17 is provided at the bottom of the sample carrier box 2. This facilitates adjusting the height of the sample carrier box 2 to facilitate the calibration of the laser light path. In specific implementation, the lifting rod 17 is a lifting screw.

[0040] In specific implementation, the sample carrier box 2 is fabricated by 3D printing, and the material is an alloy material.

[0041] In specific implementation, the size of the sample accommodation cavity 9 is adapted to the size of the sample to be measured 10.

[0042] In specific implementation, the distance between the incident hole 6 and the second exit hole 8 is 10 - 30 mm. In this way, the fluorescence emitted from the second exit hole can be prevented from being too weak, thereby avoiding too large statistical errors and affecting the accuracy of the measurement result.

[0043] Working process:

[0044] (1) Measuring the emission spectrum, refer to Figure 4

[0045] A. When measuring the emission spectrum, the light path is calibrated by operating the lifting rod (or manually lifting the sample carrier box) and moving the sample carrier box left and right, and the size of the laser spot is adjusted so that the laser emitted by the laser can just enter from the incident hole;

[0046] B. Turn off the laser, open the light-shielding cover, place the sample to be measured, and close the light-shielding cover;

[0047] C. Turn on the laser, start the measurement, collect the information collected by the optical fiber probe through the spectrometer, and process the information collected by the spectrometer through the computer.

[0048] (2) Measuring the afterglow, refer to Figure 5

[0049] A. When measuring the afterglow, the light path is calibrated by operating the lifting rod (or manually lifting the sample carrier box) and moving the sample carrier box left and right, and the size of the laser spot is adjusted so that the laser emitted by the laser can just enter from the incident hole;

[0050] B. Turn off the laser, open the light-shielding cover, place the sample to be measured, and close the light-shielding cover;

[0051] C. Turn on the laser and start the measurement. Collect the information collected by the silicon photodiode through the acquisition card, and process the information collected by the acquisition card through the computer to obtain the afterglow decay characteristics.

[0052] (3) Measure the conversion efficiency and conversion efficiency uniformity. See Figure 5

[0053] A. When measuring the conversion efficiency and conversion efficiency uniformity, calibrate the optical path by operating the lifting rod (or manually lifting the sample carrier box) and moving the sample carrier box left and right, and adjust the laser spot size so that the laser emitted by the laser can just enter through the incident hole;

[0054] B. Turn off the laser, open the light shield, place the sample to be measured, and close the light shield;

[0055] C. Start the low-speed motor to rotate it evenly (the rotation speed is about 0.1 r / s), turn on the laser (the laser frequency is generally 100 - 1000 Hz), start the measurement, collect the information collected by the silicon photodiode through the acquisition card, and process the information collected by the acquisition card through the computer to obtain the conversion efficiency and conversion efficiency uniformity.

[0056] The processing method of the conversion efficiency is as follows:

[0057]

[0058] Among them, U n is the voltage output by the acquisition card during the nth measurement; Q is the laser energy at the measurement point; η n is the conversion efficiency measured for the nth time; is the average value of the conversion efficiency; n is the number of laser irradiations.

[0059] The processing method of the conversion efficiency uniformity is as follows:

[0060]

[0061] In the above formula, U η is the conversion efficiency uniformity of the crystal when the laser is stable; η max is the maximum value of the conversion efficiency in n measurements; η min is the minimum value of the conversion efficiency in n measurements.

[0062] Working principle: During operation, the laser is emitted from the laser and enters through the incident hole of the sample carrier box, irradiating the sample to be measured. The sample to be measured emits fluorescence under the excitation of the laser, and exits from the second exit hole under the reflection of the sample accommodation cavity, and is detected by the corresponding instrument. The corresponding performance test results can be obtained through computer processing. Moreover, the performance indicators collected by the present invention are complete, which is conducive to constructing a complete crystal quality evaluation system and providing a complete and reliable reference for the screening of conversion crystals. The laser directly transmits through the first exit hole, which can effectively reduce the influence of the laser on the accuracy of the performance test of the fluorescence conversion crystal. In addition, the sample to be measured in the present invention is installed in a sample carrier box with a closed perimeter, which can effectively resist the interference of ambient light and further improve the accuracy of performance measurement.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent replacements made to the technical solutions of the present invention without departing from the purpose and scope of the present technical solution should be covered within the scope of the claims of the present invention.

Claims

1. A device for measuring the optical properties of a fluorescence conversion crystal, comprising a laser and a computer, characterized in that: Also includes a sample carrier box, A sample accommodating cavity is provided in the middle of the sample carrier box, and the sample accommodating cavity passes through the top of the sample carrier box and is used to place the sample to be tested; an inlet hole is provided on one side of the sample carrier box, and a first outlet hole and a second outlet hole are provided on the other side opposite thereto, and all the outlet holes are connected to the inlet hole, and the center line of the first outlet hole is on the same axis as the center line of the inlet hole; when working, the laser energy emitted by the laser can be emitted from the inlet hole to irradiate the sample to be tested; A signal detection device is installed in the second exit hole, and the signal detection device is an optical fiber probe and a silicon photodiode, and the optical fiber probe and the silicon photodiode are selectively installed in the second exit hole; when the signal detection device is an optical fiber probe, the optical fiber probe is connected to a spectrometer through a wire, and the spectrometer is connected to a computer through a wire; when the signal detection device is a silicon photodiode, the silicon photodiode is connected to an acquisition card through a wire, and the acquisition card is connected to a computer through a wire.

2. The device for measuring the optical properties of a fluorescence conversion crystal according to claim 1, characterized in that: A rubber wheel is arranged at the bottom of the sample accommodating chamber, and the rubber wheel is driven by a motor arranged outside the sample carrying box to realize rotation; the sample to be tested is circular, and the bottom of the sample to be tested is just tangent to the top of the rubber wheel, and the sample to be tested is driven to rotate by the rotation of the rubber wheel.

3. The device for measuring the optical properties of a fluorescence conversion crystal according to claim 2, characterized in that: Two auxiliary rollers are symmetrically arranged in the sample accommodating cavity. The two auxiliary rollers and the rubber wheel are used to jointly support the circumferential surface of the sample to be tested so that it is suspended in the sample accommodating cavity.

4. The device for measuring the optical properties of a fluorescence conversion crystal according to claim 1, characterized in that: The inner wall of the sample accommodating cavity is uniformly coated with a reflective film.

5. The device for measuring the optical properties of a fluorescence conversion crystal according to claim 1, characterized in that: The sample carrying box is provided with a matching light shielding cover, and the light shielding cover is provided with three through holes, which are respectively opposite to the incident hole, the first exit hole and the second exit hole of the sample carrying box.

6. The device for measuring the optical properties of a fluorescence conversion crystal according to claim 1, characterized in that: A lifting rod is arranged at the bottom of the sample carrying box.

7. The device for measuring the optical properties of a fluorescence conversion crystal according to claim 1, characterized in that: The distance between the incident hole and the second incident hole is 10 to 30 mm.

8. A method for measuring the optical properties of a fluorescence conversion crystal, characterized in that: The method of measuring using the device of claim 1 comprises the following steps: A. Place the sample carrier box on the light path of the laser, turn on the laser, and adjust the position of the sample carrier box and the laser spot size so that the laser emitted can just enter from the incident hole; B. Turn off the laser and put the sample to be tested into the sample carrier box; C. When measuring the emission spectrum, the optical fiber probe is installed in the second exit hole; the laser is turned on, the information collected by the optical fiber probe is collected by the spectrometer, and the information collected by the spectrometer is processed by the computer to obtain the emission spectrum; When measuring afterglow, the laser is turned on and the silicon photodiode is installed in the second exit hole; the information collected by the silicon photodiode is collected by the acquisition card, and the information collected by the acquisition card is processed by the computer to obtain the afterglow attenuation characteristics; When measuring conversion efficiency and conversion efficiency uniformity, the silicon photodiode is installed in the second exit hole; the laser is turned on, the information collected by the silicon photodiode is collected by the acquisition card, and the information collected by the acquisition card is processed by the computer to obtain a single measurement conversion efficiency. After each measurement, the sample to be measured is rotated to measure the conversion efficiency at different positions of the sample to be measured, and the average conversion efficiency and the uniformity of the conversion efficiency are obtained by processing with the computer.

Images