Device for measuring modulation transfer function of optical system and method thereof

Abstract

The invention discloses a device for measuring a modulation transfer function of an optical system and a method thereof. A target generator of the device comprises a knife edge target (4), a light source (1) and an electrical machine (3), wherein the electrical machine drives the knife edge target (4), so that an inclined angle beta is formed between the arrangement direction of a knife edge pixel (12) of the knife edge target (4) and that of a pixel (13) of an area array detector, and the inclined angle meets the following condition: ds=d sin beta, wherein the ds is a sampling distance, and the d is the size of the edge length of the pixel of the area array detector. When measuring, the modulation transfer function, the electrical machine drives the knife edge target (4) to rotate at the angle of beta to perform image data collecting and data processing so as to obtain modulation transfer function of the optical system to be measured. The invention adopts the knife edge target to realize an oversampling technology and improve the sampling rate, thereby being capable of measuring the modulation transfer function of the optical system to be measured without a relay amplifying system, being capable of measuring the maximum frequency which is higher than the Nyquist frequency of the area array detector, simplifying a measuring system, and avoiding complex assembling and correcting work when manufacturing apparatuses.

Description

technical field [0001] The invention relates to a device and method for measuring the modulation transfer function of an optical system. Background technique [0002] The modulation transfer function reflects the frequency response characteristics of an optical system or an optoelectronic system, and is an important performance index for quantitatively evaluating the imaging quality of an optical system or an optoelectronic system. [0003] The early modulation transfer function measurement adopts the scanning method, that is, the unit detector is used to scan the image plane to complete the measurement. With the maturity of area array detectors such as CCD and CMOS, the current measurement of modulation transfer function mainly adopts image Fourier analysis method, that is, pinholes, slits, etc. are used as targets, and CCD or CMOS area array detectors are used to detect the light intensity of the image plane. The distribution is followed by computer analysis processing to...

AI Technical Summary

Problems solved by technology

[0006] The following problems exist in the use of the relay amplification system: (1) the image quality of the relay amplification system will directly affect the measurement accuracy of the modulation transfer function; to modulate the increase in the measurement error of the transfer function; (3) the high-magnification relay amplification system will weaken the energy on the detector pixel and reduce the signal-to-noise ratio; (4) the use of the relay amplification system will increase the volume of the measuring instrument and cost increase

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