Spectral-domain optical coherence tomography imaging system based on Fresnel spectrometer

Abstract

The invention relates to a spectral-domain optical coherence tomography imaging system based on a Fresnel spectrometer, which is characterized by comprising a Michelson interferometer, the Fresnel spectrometer and a Fourier transformation module. The Michelson interferometer sends coherent light which is formed by superposing sample light returned from various layers of a sample with reference light into the Fresnel spectrometer, the coherent light is emitted onto a Fresnel zone plate parallelly through a collimating lens and an expanded beam lens respectively, and is expanded at the same interval according to the wave number and then projected to a linear array CCDs (charge coupled devices) by the Fresnel zone plate, frequency spectrum data of the coherent light are read by the linear array CCDs and sent to the Fourier transformation module, and then recovered into information of spatial position of the sample by means of discrete Fourier transformation through the Fourier transformation module. The spectral-domain optical coherence tomography imaging system based on the Fresnel spectrometer can be applied to not only spectral-domain optical coherence tomography imaging but also spectral analysis having requirements for wavelength-wave number conversion and resampling for imaging or detecting and required to be expanded uniformly according to the wave number, and especially can be applied to the biomedical imaging process.

Description

technical field [0001] The invention relates to a frequency-domain optical coherence tomography system, in particular to a frequency-domain optical coherence tomography system based on a Fresnel spectrometer. Background technique [0002] Optical coherence CT (Optical Coherence Tomography, OCT for short) technology has developed rapidly in the past ten years. This technology can perform tomographic imaging of biological tissues or human tissues, and its resolution is much higher than that of X-ray imaging and ultrasonic imaging. In particular, frequency-domain optical coherent CT (FD-OCT) technology not only has high-resolution tomographic imaging capabilities, but also has frequency-domain parallel reading capabilities, which can read a line of optical signals along a certain depth direction of the sample at one time. FD-OCT OCT technology also has the advantages of high sensitivity and great potential for high-speed imaging. [0003] In the fiber-based FD-OCT system, the ...

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Problems solved by technology

However, at this time, the frequency spectrum recorded on the linear array CCD is expanded according to approximately equally spaced wavelengths, and the Fourier transform requires the frequency spectrum to be evenly expanded according to the wave number, otherwise the longitudinal resolution of the spatial domain signal after the Fourier transform will be changed. Difference

The existing frequency-domain optical coherence tomography system also needs to do wavelength-wavenumber conversion and resampling data post-processing, which greatly affects the imaging speed of the imaging system

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