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A reflective difference device for obliquely incident light based on Fourier transform

A Fourier transform, incident light technology, applied in the field of optical instruments, can solve the problems of high price, obstructing the miniaturization, simplification and high efficiency of oblique incident light reflection difference devices, and bulky lock-in amplifiers, so as to improve performance. , fast sampling rate, space saving effect

Active Publication Date: 2020-05-12
FUDAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The lock-in amplifier is not only bulky, but also expensive, which hinders the miniaturization, simplification and high efficiency of the oblique incident light reflection difference device, and is the technical bottleneck for the development of the portable oblique incident light reflection difference device

Method used

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  • A reflective difference device for obliquely incident light based on Fourier transform
  • A reflective difference device for obliquely incident light based on Fourier transform
  • A reflective difference device for obliquely incident light based on Fourier transform

Examples

Experimental program
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Effect test

Embodiment 1

[0044] according to figure 1As shown, a Fourier transform-based reflectance difference device for obliquely incident light of the present invention is produced. The monochromatic light generator 1 adopts a helium-neon laser with an output wavelength of 632.8nm; the output light of the laser is expanded into a collimated light through a beam expander 3; The polarizer 5 becomes linearly polarized light, and its vibration direction is 45° to the horizontal direction; the polarization modulator 6 uses a horizontally placed photoelastic modulator to periodically modulate the polarization state at 50 kHz; the outgoing light passes through the phase shifter 7, The phase shifter 7 adopts a zero-order half-wave plate whose fast axis is along the p-polarization direction, and rotating the half-wave plate with the fast axis as the rotation axis can introduce an adjustable phase difference; the outgoing light is focused by the lens 8, and the lens 8 is realized by the scanning field mirr...

Embodiment 2

[0058] Implemented according to Embodiment 1, the light transmission axis of the polarizer 5 is along the horizontal direction, the polarization modulator 6 is placed at 45° to the horizontal direction, and the phase shifter 7 is placed behind the imaging lens 9; the lens 8 uses a cylindrical lens to replace the scanning field Mirror and vibrating mirror, the focal length of the lens is 5cm; the photodetector 12 uses a diode array containing 152 photodiodes to replace the linear photodiode; the discrete Fourier transform method is used to analyze the time-domain periodic signal, the sampling frequency is 625kHz, and the number of sampling points is 1000 pieces.

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Abstract

The invention relates to an oblique incident light reflection difference device based on Fourier transform. The device comprises an incident light path for periodically modulating a the polarization state of incident light, a reflection light path for detecting a the polarization state of reflecting light and an equipment management unit for carrying out data acquisition and processing and system control. According to the device provided by the invention, the equipment management unit is used for analyzing a signal by adopting a Fourier transform method and two sets of lock-phase amplifiers are effectively replaced; the equipment management unit has the advantages of miniaturization, simplicity, low cost, high precision and the like and is a precondition for preparing the portable oblique incident light reflection difference device; wide application of the device in the fields including in-situ and real-time detection of thin film growth and mutual effect of high-flux characterized biomolecules and the like is further expanded.

Description

technical field [0001] The invention belongs to the technical field of optical instruments, and in particular relates to a detection device for in-situ real-time detection of film thickness changes by using an optical method. Background technique [0002] Oblique incident light reflectance difference technology is a highly sensitive optical detection method developed in recent years. It has outstanding characteristics such as high sensitivity, no damage, and in-situ real-time measurement. It has been used for real-time monitoring of film growth and high-throughput detection of biomolecular interactions Function and other fields have been widely used. The inventor and his collaborators have developed an obliquely incident light reflectance difference technology for in-situ real-time monitoring of film growth, and have obtained two authorized invention and utility model patents (patent numbers: ZL03153938.6 and Z103276452.9). The inventor and his collaborators have developed ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N21/41G01B11/06
CPCG01B11/06G01N21/41G01N2021/4126
Inventor 费义艳陈儒朱成钢葛碧临
Owner FUDAN UNIV