Dispersion compensating method and system for optically coherent chromatographic imaging

Abstract

The present invention discloses dispersion compensating method and system for optically coherent tomographic imaging (OCT). The system has one increased blazed grating parallelly set with the original blazed grating in a single grating fast scanning optical delay line, and thus one independently regulated variable of interval between two blazed gratings and capacity of generating group velocity dispersion and third-order dispersion in great varying range and arbitrary sign combination, so that the OCT system may obtain precise matching between the dispersion of the reference arm and the dispersion of the sample arm and longitudinal resolution approaching the theoretical calculated value. The double grating system has wide dispersion regulating range, wide compensation spectrum range and small residual dispersion other than the capacity of independently controlling phase delay and group delay, and possesses three functions of depth scan, phase modulation and dispersion compensation.

Description

technical field [0001] The invention relates to an optical coherence tomography (OCT) technology, in particular to a dispersion compensation method and system in the optical coherence tomography. Background technique [0002] Optical coherence tomography (OCT) is a biomedical optical imaging technology with tomographic function. It is an important minimally invasive imaging tool that can perform clinical functions such as early diagnosis, process monitoring, and surgical guidance. OCT, with its advantages of ultra-high resolution, ultra-fast imaging speed, no radiation damage, diversity of optical information, moderate price, compact structure, and good compatibility with existing medical instruments, is currently widely favored in clinical medicine. Optical means that play an important role in the [0003] In structural OCT and various functional OCT systems, it is necessary to introduce Doppler frequency shift to realize heterodyne modulation. Doppler shift is usually a...

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Problems solved by technology

However, the different signs of group velocity dispersion (GVD) and third-order dispersion (TOD) introduced by this method cannot compensate the positive GVD and TOD introduced by the above-mentioned crystal at the same time, that is, the system dispersion can only be matched to the second order, but there are still serious problems. Third-order dispersion mismatch, which makes the actual vertical resolution of the system lower than the theoretical value due to dispersion mismatch

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