Huazhong University of Science and Technology

Honggang Gu

Shiyuan Liu

Xiuguo Chen

Hao Jiang

Baokun Song

Chuanwei Zhang

Song Zhang

Mingsheng Fang

Li Liu

Simin Zhu

Weichao Du

Jiamin Liu

Zhicheng Zhong

Weiqi Li

Zhengfeng Guo

Lei Zhong

The disclosure provides a method for ptychography position correction based on probe weighting. The method includes: collecting diffraction light field intensity information and simultaneously initializing information functions of illumination probes and a sample to be tested and probe positions; obtaining and importing an exit wave into a propagation model to obtain a simulated diffraction light field and replacing the diffraction light field intensity information to obtain an updated diffraction light field; importing the updated diffraction light field into a backpropagation model and obtaining a diffraction exit wave and updating the information functions of the sample to be tested and the illumination probes at each scan position; and forming a probe matrix around the probe positions, updating the probe positions after calculating a correlation, and repeating the above steps to iterate until the predetermined number of iterations is completed or a predetermined condition is reached.

Method for ptychography position correction based on probe weighting

The invention discloses a rapid measurement method for an ultra-thin film optical constant, which includes following steps: S: using a p-light amplitude reflection coefficient rand an s-light amplitude reflection coefficient rof an incident light irradiating to an ultra-thin film to be measured to express an amplitude reflection coefficient ratio &#x3c1; of the ultra-thin film: S: performing a second-order Taylor expansion to at d=0 while taking 2&#x3c0;d/&#x3bb; as a variable to obtain a second-order approximation form; S: performing merging, simplifying and substituting processing to the second-order approximation form for transforming the same into a one-variable quartic equation; S: solving the one-variable quartic equation to obtain a plurality of solutions of the optical constant of the ultra-thin film, and obtaining a correct solution through conditional judgment, so as to achieve the rapid measurement for the ultra-thin film optical constant.

Rapid measurement method for ultra-thin film optical constant

The disclosure relates to a method for measuring a dielectric tensor of a material. Firstly, a partial conversion matrix Tand a transmission matrix Tare determined by a predetermined initial value &#x3b5;(E) of the dielectric tensor of the material to be measured, thereby obtaining a transfer matrix of an electromagnetic wave on a surface of the material to be measured by the partial conversion matrix T, the transmission matrix T, and an incident matrix T, a theoretical Mueller matrix spectrum MM(E) of the material to be measured is determined by the transfer matrix T. A fitting analysis is performed on the theoretical Mueller matrix spectrum MM(E) and a measured Mueller matrix spectrum MM(E) of the material to be measured to obtain the dielectric tensor of the material to be measured.

Method for measuring dielectric tensor of material

A method and a device for real-time attitude angle measurement based on the field of view effect of the birefringent crystal are provided. The device includes a high-speed polarization measurement module and an object attitude adjustment module connected to each other. The high-speed polarization measurement module includes a polarizer unit and a real-time polarization analyzer unit, respectively located on two opposite sides of the object attitude adjustment module. The object attitude adjustment module includes an attitude angle controller, a roll angle adjustment unit, a pitch angle adjustment unit, a yaw angle adjustment unit, and a height adjustment unit respectively connected to the attitude angle controller, and a birefringent crystal. The method includes an algorithm for real-time extraction of object attitude angle according to optical parameters measured by the high-speed polarization measurement module, and a method for compensating attitude angle measurement errors.

Method and device for real-time attitude angle measurement based on field of view effect of birefringent crystal

The present invention belongs to the field of optical detection devices, and specifically discloses a polarization modulator and a polarization measurement system, comprising a rotating compensator and a polarizer, in which the rotating compensator is a continuously rotating composite waveplate, the composite waveplate is composed of a plurality of single-waveplates of the same material, and the overall structure of the composite waveplate is determined by thicknesses and fast axis intersection angles of the respective single-waveplates according to the optimization design of the polarization characteristic transfer matrix of the polarization modulator. The polarization modulator of the invention has the advantages of simple structure, easy processing and a wide applicable wavelength range, and a wide-waveband polarization measurement system can be designed based on the polarization modulator, which is adapted to the requirements of wide-waveband precision polarization measurement.

Optimization methods of polarization modulator and polarization measurement system

A material optical transition analysis method and system are provided, the method includes: determining a dielectric function spectrum of a material to be analyzed, calculating a second derivative spectrum of the dielectric function spectrum related to the excitation light energy, and performing the CP fitting analysis on the second derivative spectrum to obtain a CP analysis result diagram of the material; drawing an energy band structure diagram and a PDOS diagram of the material, and drawing an energy difference diagram between CBs and VBs according to the energy band structure diagram of the material; determining spatial positions of CPs and the corresponding CBs and the VBs according to the CP analysis result diagram of the material and the energy difference diagram between the CBs and the VBs; and finally indicating the CBs and the VBs in the energy band structure diagram, and determining the particle types participating in formation of the CPs in the PDOS diagram to complete the material optical transition analysis. The invention realizes the analysis and interpretation of the optical transition characteristics occurring at the materials from the perspective of physics, which has the advantages of reliable operation process system and accurate and reliable analysis results.

Material optical transition analysis method and system

The present invention discloses a high temporal resolution Mueller matrix elliptical polarization measuring device and method. In the incident light path, four polarization modulation channels are used to split and modulate a pulse laser beam into four polarized beams in independent polarization states. Due to different light path differences, the pulse beams have a time interval of several nanoseconds, and thus four pulse laser beams are successively irradiated on the surface of the sample. In the reflected light path, six channel polarization detection modules are used to synchronously measure the Stokes vectors of the reflected beams on the sample surface. By using known incident and reflected Stokes vectors of the four pulse beams, linear equations can be solved to obtain the Mueller matrix of the sample.

High temporal resolution Mueller matrix elliptical polarization measuring device and method

An alignment method for optical axes of a composite waveplate includes rotating a rotatable waveplate, which rotates about a central axis with respect to a fixed waveplate, and adjusting the rotation angle thereof until the differences between the spectral parameters of the composite waveplate and ideal spectral parameters are smaller than preset values.

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Hubei, China

Honggang Gu