The present invention discloses application of a multi-channel optical nonlinearity measurement technology to measure the third-order nonlinear refraction coefficient of a medium. According to the present invention, with numerical simulation, a linear relationship is formed in the range of 0-0.65; in the experiment, the results of a sample to be measured and a standard sample can be directly measured, and by using the linear range, the third-order nonlinear refraction coefficients of a plurality of samples to be measured can be measured through the measuring, such that the complex fitting calculation required by the original single-4f system is avoided; and the experiment results verify that the method of the present invention is correct.

Multi-channel material optical nonlinearity measurement method

The invention discloses an improved Z-scanning measurement method, wherein different to-be-measured samples are pre-scanned so as to automatically determine the optimum measurement light intensity corresponding to the to-be-measured samples; at the optimum measurement light intensity, the following problems are effectively avoided: 1) influence of high-order non-linear optics effect due to excessive light intensity; and 2) influence caused by excessive noise signals due to weakness of the light intensity; therefore, the measurement result is accurate and reliable. In an apparatus, a pluralityof reflectors and aperture diaphragms are arranged for shaping the beam. In the apparatus, corresponding devices are added to measure influences, caused by laser energy fluctuation, instable laser mold locking and sample breaking, during the measurement; and corresponding devices are added to avoid influence of thermal effects and polarization state during the measurement. On the mentioned basis,the incident light source is replaceable, the polarization state is adjustable, and closed pore and opened core data can be measured at the same time.

Improved Z-scanning measurement method

The invention discloses a method for measuring nonlinear refractive index under a thermal halo effect and belongs to the technical field of thermo-optics and electro-optics; the method comprises the following steps: 1) preparing an antimonene-ethanol dispersion liquid, and putting the antimonene-ethanol dispersion liquid into a cuvette; 2) building a measurement platform, helium-neon laser passingthrough a spectroscope, a beam of light serving as reference light to be incident to an optical power meter, another beam of light being focused to the center position of the cuvette through a convexlens, and finally, a pattern being received by CCD; an attenuator being arranged between the helium-neon laser and the spectroscope and being used for adjusting the optical power to realize adjustable optical power; 3) calculating the nonlinear refractive index according to the detection result; and 4) verifying the nonlinear refractive index calculated in the step 3). According to the method inthe invention, the thermo-optical experiment and Z-scan experiment based on the antimonene-ethanol nanometer material dispersion liquid respectively provide accurate experimental data for the change of the nonlinear refractive index caused by thermal halo and material characteristics, the experimental technology is simple to operate, the experimental period is shortened, and the method is simple and easy to operate.

Method for measuring nonlinear refractive index under thermal halo effect

The invention disclose an non-linear refractivity test method for eliminating the effect of non-linear absorption, which is based on phase conjugation and 4f phase coherent imaging technique, wherein a laser beam is filtered via a stop and focused on a sample via a Fourier lens, to be reflected to invert direction and pass the sample and the Fourier lens, the laser beam is splitted via a beam splitter to be attenuated and received by a CCD camera. The invention is characterized in that the invention respectively tests a non-sample picture, a linear picture, an absorption refractive picture and an absorption picture, respectively integrates the linear picture and non-sample picture to obtain the energy of the linear pulse after the sample and the total energy of the incident pulse, which ratio is the linear permeability of the sample, and the invention uses the absorption picture to digitally fit the absorption refractive picture to obtain the non-linear refractive index of the sample. The invention can obtain non-linear refractive index without the test on non-linear absorption factor, to eliminate the effect of non-linear absorption on test result and improve test accuracy.

Jihua Gu

Papers

Method for measuring non-linear refraction nature for eliminating nonlinear absorption influence