Full-range imaging method and system based on mobile optical grating spatial carrier frequency spectral domain OCT (optical coherence tomography)

Abstract

The invention discloses a full-range imaging method and system based on mobile optical grating spatial carrier frequency spectral domain OCT (optical coherence tomography). According to the method and the system, a mobile optical grating replaces a reference mirror in the conventional spectral domain OCT, and a spatial carrier frequency which does not need optical path modulation is introduced in the transverse scanning direction. A detected interference spectrum signal is subjected to Fourier transform along the transverse scanning direction at first, then bandpass filtering centering on the amount of the spatial carrier frequency is carried out, then the filtered signal is subjected to inverse Fourier transform, and finally, the signal is subjected to Fourier transform along the axial direction to obtain full-range OCT images of a sample after mirror images are eliminated. By adopting the method and system, the full-range spectral domain OCT images can be obtained on the premise that any additional optical path difference is not introduced, and the sensitivity drop caused by accumulated optical path differences in the conventional spatial carrier frequency method is avoided.

Description

technical field [0001] The present invention relates to optical coherence tomography (OCT) technology, in particular to a full-scale imaging method and system based on moving grating space carrier spectrum domain OCT. Background technique [0002] Optical coherence tomography (OCT) is a non-invasive and non-contact imaging technology. As a brand-new and rapidly developing imaging technology, it has a series of advantages such as high resolution, non-destructive and real-time imaging. The spectral domain OCT (Spectral domain OCT, SD-OCT) system is the second generation of OCT technology. has obvious advantages. The biggest problem in the current SD-OCT system is the mirror image caused by the complex conjugate term generated by the Fourier transform of the real function. In practical applications, in order to avoid confusion between the mirror image and the actual image, the sample to be tested is generally placed on the side of the zero optical path difference position, an...

AI Technical Summary

Problems solved by technology

However, in the linear B-M method, the amount of displacement π / 2 is introduced between adjacent A-scans. If the horizontal scanning range is large, a large optical path difference will be accumulated

Since the sensitivity of the SD-OCT system decreases as the imaging depth increases, this accumulated optical path difference will cause the signal-to-noise ratio of the final image to decrease along the transverse scanning direction

Images