Color Z-scan measurement system

Abstract

The invention discloses a color Z scanning measurement system which comprises a color laser, a beam splitter, a reference light integrating sphere, a reference light spectrograph, a focus lens, a sample, a displacement table, a test light integrating sphere, a test light spectrograph, a stepping motor controller, a computer and the like. According to the system, Z scanning parameters of the nonlinear optical material at multiple wavelength positions can be simultaneously or continuously measured, the laser does not need to be replaced, and the measurement efficiency and accuracy are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of nonlinear optical material measurement, and in particular to a color Z scanning measurement system, which can realize Z scanning measurement of nonlinear optical materials at multiple wavelength positions. Background Art

[0002] Nonlinear optical materials have a wide range of applications, and their performance evaluation is crucial. Z-scan technology, as a measurement method, can accurately measure the key parameters of nonlinear optical materials. The traditional Z-scan system configuration is as follows: Figure 1 As shown in the figure, the system integrates core components such as monochromatic laser, beam splitter, reference light detector, focusing mirror, sample, translation stage, test light detector, stepper motor controller and computer [M. Sheikbahae, A. A. Sad, and E. W. Vanstryland, "High-Sensitivity, Single-Beam N2 Measurements," Optics Letters, vol. 14, no. 17, pp. 955-957, 1989.]. The laser beam emitted by the monochromatic laser is divided into two by the beam splitter, forming two paths of reference light and test light. Among them, the reference light is collected by the reference light detector, and the test light is focused on the sample by the focusing mirror. The light intensity after penetrating the sample is collected by the test light detector. The sample is fixed on the translation stage and driven by the stepper motor controller to realize point-by-point scanning in the direction of the optical axis, and the transmittance data at each scanning position is recorded at the same time, thereby completing the entire Z scanning measurement process.

[0003] However, this method can only perform Z-scan measurements at a single wavelength each time due to its single wavelength. If a Z-scan experiment needs to be performed at different wavelengths, the laser must be replaced manually, which is not only time-consuming and labor-intensive, but also increases the complexity and uncertainty of the experimental operation. Summary of the invention

[0004] In order to solve the limitation that the traditional Z scanning system can only measure at a single wavelength, the present invention provides a color Z scanning measurement system, which can simultaneously or continuously measure the Z scanning parameters of nonlinear optical materials at multiple wavelength positions without replacing the laser, thereby greatly improving the measurement efficiency and accuracy.

[0005] The technical solution of the present invention is as follows:

[0006] A color Z-scanning measurement system, comprising:

[0007] Color lasers, which emit laser beams containing multiple wavelengths;

[0008] A beam splitter, arranged at the output end of the color laser, for splitting the laser beam into a reference light and a test light;

[0009] A reference light integrating sphere, arranged at the reference light output end of the beam splitter, for collecting reference light;

[0010] A reference light spectrometer, connected to the reference light integrating sphere via an optical fiber, and used to measure the spectral distribution of the reference light;

[0011] A focusing mirror, arranged at the test light output end of the beam splitter, for focusing the test light onto the sample;

[0012] A translation stage, used to fix the sample and capable of stepping and scanning the sample along the optical axis under the drive of a stepping motor controller; wherein the sample is located at the focus of the focusing mirror and absorbs the test light;

[0013] A test light integrating sphere, arranged behind the sample, for collecting the test light absorbed by the sample;

[0014] A test light spectrometer, connected to the test light integrating sphere via an optical fiber, is used to measure the spectral distribution of the test light;

[0015] A stepper motor controller, used for controlling the stepping scanning of the translation stage;

[0016] The computer is connected to the reference light spectrometer, the test light spectrometer and the stepper motor controller respectively, and is used for receiving spectrum data, controlling step scanning, and processing and analyzing data.

[0017] Preferably, the beam splitter has high light transmittance and high stability to ensure that the intensity and wavelength distribution of the reference light and the test light are consistent.

[0018] Preferably, the wavelength range contained in the laser light beam emitted by the color laser can be selected or adjusted according to experimental requirements.

[0019] Preferably, the reference light integrating sphere and the test light integrating sphere are both designed with a structure for uniformly collecting light to avoid spectral distortion.

[0020] Preferably, the focusing mirror has a dispersion correction capability to ensure that the position and size of the focusing point of light of different wavelengths on the sample are consistent.

[0021] Preferably, the translation stage has high precision and high stability to ensure the accuracy of the scanning position.

[0022] Preferably, the computer is also used to calculate the transmittance and nonlinear refractive index parameters of the sample at each scanning position based on the spectral data measured by the reference light spectrometer and the test light spectrometer.

[0023] Preferably, it also includes a calibration and monitoring module, which is connected to the color laser and is used to calibrate and monitor the laser wavelength to ensure that the wavelength output by the color laser is accurate.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) The present invention can complete Z scanning measurement at different wavelength positions, and then obtain the nonlinear optical parameters of the material at different wavelength positions.

[0026] 2) The use of color lasers enables simultaneous or continuous measurement of multiple wavelengths without the need to replace the laser.

[0027] 3) The design of the integrating sphere ensures uniform collection of reference light and test light, avoiding spectral distortion. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of a conventional Z-scan measurement system;

[0029] Figure 2 Schematic diagram of a color Z-scanning measurement system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be described in detail below with reference to the accompanying drawings and embodiments, but the protection scope of the present invention shall not be limited thereto.

[0031] See also Figure 2 , Figure 2 The schematic diagram of the color Z scanning measurement system of the embodiment of the present invention is shown in the figure. A color Z scanning measurement system can simultaneously or continuously measure the Z scanning parameters of nonlinear optical materials at multiple wavelength positions without replacing the laser, which greatly improves the measurement efficiency and accuracy. The system includes a color laser, a beam splitter, a reference light integrating sphere, a reference light spectrometer, a focusing mirror, a sample, a displacement stage, a test light integrating sphere, a test light spectrometer, a stepper motor controller and a computer. The beam splitter is placed along the light beam emission direction of the color laser. The beam splitter divides the incident light beam into a reflected light beam and a transmitted light beam. The reflected light beam is used as a reference light beam. In the propagation direction of the reference light beam is the reference light integrating sphere. The reference light spectrometer is connected to the port of the reference light integrating sphere through an optical fiber. The transmitted light beam is a test light beam. In the propagation direction of the test light beam are the focusing mirror, the sample and the test light integrating sphere in sequence. The sample is mounted on the displacement stage. The test light spectrometer is connected to the port of the test light integrating sphere through an optical fiber. The stepper motor controller is connected to the displacement stage. The stepping motor controller, the reference light spectrometer and the test light spectrometer are connected to the computer.

[0032] Working principle:

[0033] Color laser: emits a laser beam containing multiple wavelengths that can be selected or adjusted according to experimental requirements.

[0034] Beam splitter: Splits the laser beam emitted by the color laser into two beams, one as reference light and the other as test light. The beam splitter needs to have high light transmittance and high stability to ensure that the intensity and wavelength distribution of the two beams are consistent.

[0035] Reference light integrating sphere and reference light spectrometer: The reference light is collected by the reference light integrating sphere and connected to the reference light spectrometer via optical fiber. The reference light spectrometer is used to measure the spectral distribution of the reference light as a benchmark for subsequent data processing. The design of the integrating sphere must ensure uniform collection of the reference light to avoid spectral distortion.

[0036] Focusing mirror: Focuses the test light onto the sample. The focusing mirror must have good dispersion correction capabilities to ensure that the position and size of the focus points of light of different wavelengths on the sample are consistent.

[0037] Sample and translation stage: The sample is fixed on the translation stage, which is driven by a stepper motor controller to step and scan the sample along the optical axis. The translation stage must have high precision and high stability to ensure the accuracy of the scanning position.

[0038] Test light integrating sphere and test light spectrometer: The test light absorbed by the sample is collected by the test light integrating sphere and connected to the test light spectrometer through an optical fiber. The test light spectrometer is used to measure the spectral distribution of the test light, thereby obtaining the transmission spectrum of the sample at each scanning position.

[0039] Computer and data processing: The computer receives the data from the reference light spectrometer and the test light spectrometer, and processes and analyzes them. By comparing the spectral distribution of the reference light and the test light, the transmittance, nonlinear refractive index and other parameters of the sample at each scanning position can be calculated. The computer also needs to control the stepper motor controller to realize the step scanning and data collection of the sample.

[0040] Example:

[0041] The color laser is a supercontinuum laser, emitting a spectrum range of 400-2400nm. The beam splitter is made of fused quartz glass, the sum of the reflectivity of the front and rear surfaces is about 9%, and the transmittance is about 91%. The inner diameter of the reference light integrating sphere is 150mm, the reflectivity of the internal coating is about 97%, and the number of openings is 3. The spectral detection range of the reference light spectrometer is 350-950nm, and the slit size is 70μm. The focal length of the focusing mirror is 150mm. The inner diameter of the test light integrating sphere is 150mm, the reflectivity of the internal coating is about 97%, and the number of openings is 4. The spectral detection range of the test light spectrometer is 350-950nm, and the slit size is 70μm. The scanning range of the translation stage is 150mm.

[0042] Experiments have shown that the color Z-scan measurement system of the present invention can realize Z-scan measurement at multiple wavelength positions, has the advantages of simple operation, accurate measurement, high efficiency, etc., and is suitable for performance evaluation and scientific research of nonlinear optical materials.

Claims

1. A color Z-scan measurement system, characterized in that: include: Color lasers, which emit laser beams containing multiple wavelengths; A beam splitter, arranged at the output end of the color laser, for splitting the laser beam into a reference light and a test light; A reference light integrating sphere, arranged at the reference light output end of the beam splitter, for collecting reference light; A reference light spectrometer, connected to the reference light integrating sphere via an optical fiber, and used to measure the spectral distribution of the reference light; A focusing mirror, arranged at the test light output end of the beam splitter, for focusing the test light onto the sample; A translation stage, used to fix the sample and capable of stepping and scanning the sample along the optical axis under the drive of a stepping motor controller; wherein the sample is located at the focus of the focusing mirror and absorbs the test light; A test light integrating sphere, arranged behind the sample, for collecting the test light absorbed by the sample; A test light spectrometer, connected to the test light integrating sphere via an optical fiber, is used to measure the spectral distribution of the test light; A stepper motor controller, used for controlling the stepping scanning of the translation stage; The computer is connected to the reference light spectrometer, the test light spectrometer and the stepper motor controller respectively, and is used for receiving spectrum data, controlling step scanning, and processing and analyzing data.

2. The color Z-scanning measurement system according to claim 1, characterized in that: The beam splitter has high light transmittance and high stability to ensure that the intensity and wavelength distribution of the reference light and the test light are consistent.

3. The color Z-scanning measurement system according to claim 1, characterized in that: The wavelength range of the laser beam emitted by the color laser can be selected or adjusted according to experimental requirements.

4. The color Z-scanning measurement system according to claim 1, characterized in that: The reference light integrating sphere and the test light integrating sphere are both designed with a structure for uniformly collecting light to avoid spectrum distortion.

5. The color Z-scanning measurement system according to claim 1, characterized in that: The focusing mirror has a dispersion correction capability to ensure that the position and size of the focusing point of light of different wavelengths on the sample are consistent.

6. The color Z-scanning measurement system according to claim 1, characterized in that: The translation stage has high precision and high stability to ensure the accuracy of the scanning position.

7. The color Z-scanning measurement system according to claim 1, characterized in that: The computer is also used to calculate the transmittance and nonlinear refractive index parameters of the sample at each scanning position according to the spectral data measured by the reference light spectrometer and the test light spectrometer.

8. The color Z scanning measurement system according to any one of claims 1 to 7, characterized in that: It also includes a calibration and monitoring module, which is connected to the color laser and is used to calibrate and monitor the laser wavelength to ensure that the wavelength output by the color laser is accurate.

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