high resolution long focal depth OCT imaging system based on optical path code and method thereof

Abstract

The invention discloses a high resolution long focal depth OCT imaging system based on an optical path code and a method thereof. A light source output beam is encoded to be multiple light beams with different optical paths by using an optical path encoder, these optical beams are focused at different depths of a sample for OCT imaging; then sample images acquired by irradiating the OCT image by light in every light beam focal depth range are acquired and assembled, thus a high-resolution sample image within a big depth scale is acquired. For the optical path code can cause the loss a part of imaging range, a detecting arm applies an orthogonal chromatic dispersion spectrograph with ultra-high spectral resolution to detect, and the spectral signal that the spectrograph involves in is finally sent to a computer; the rapid reestablishment of the high-resolution long focal depth image is realized on the computer. The high resolution long focal depth OCT imaging system can distinguish the sample information of the light beam at different depths under different coding optical paths by using the ultra-long measurement range of the orthogonal chromatic dispersion spectrograph, thus the focal depth is greatly improved.

Description

technical field [0001] The invention belongs to the technical fields of optical coherence tomography and optical microscopic imaging, and specifically relates to a high-resolution long-focus OCT imaging system and method based on optical path coding. Background technique [0002] Depth of focus (DOF) is an important parameter that affects the imaging quality of an optical system, and expanding the depth of focus is one of the important technologies to ensure that the imaging optical system has better imaging quality in a larger range. The relationship between depth of focus DOF ​​and lateral resolution Δx can be expressed as: DOF=πΔx 2 / 2λ 0 , where λ 0 is the central wavelength of the light source. It can be seen that the depth of focus decreases with the increase of the lateral resolution. Using a focusing objective lens with a larger numerical aperture can improve the lateral resolution of the system, but at the same time it also reduces the depth of focus, resulting i...

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Problems solved by technology

However, the energy utilization efficiency of the axicon lens is relatively low, and the higher the focal depth expansion factor is, the lower the energy utilization efficiency is, and it is not suitable for biological samples that are sensitive to power.

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