A Femtosecond Laser Multimodal Molecular Imaging System

Abstract

The invention provides a femtosecond laser multi-modal molecular imaging system, which uses a near-infrared band generation device to provide near-infrared band pulses with a center wavelength of 1010 nm to 1100 nm and a spectral width of less than 25 nm. The near-infrared band pulses can excite A femtosecond laser pulse with an ultra-wide spectrum is generated by a strongly nonlinear optical medium, and the dispersion accumulated by the femtosecond laser pulse reaching the tissue sample is measured and compensated by the pulse measurement compression control module, so as to eliminate the "time-domain broadening" effect to the greatest extent, and the obtained The shortest pulse can interact with tissue samples to generate a variety of spectral signals of different modalities, thus providing a variety of nonlinear molecular imaging modalities.

Description

technical field [0001] The invention relates to the technical field of femtosecond laser equipment, in particular to a femtosecond laser multi-mode molecular imaging system. Background technique [0002] The traditional supercontinuum generation method is to use 50 femtosecond low-power pulses (pulse energy less than 3nJ) to excite photonic crystal fibers with a length of less than 10 mm, while ensuring that the zero dispersion wavelength of the photonic crystal fibers used is at the generated In the supercontinuum range, for example, to generate a supercontinuum of 600-900 nanometers, the zero dispersion wavelength of the photonic crystal fiber must be in the range of 600-900 nanometers, but the supercontinuum optical pulses generated in this way are low and the power Low, poor optical path stability, unable to excite all nonlinear molecular imaging modalities. In addition, because the femtosecond laser pulse will produce a "time-domain broadening" effect when passing thro...

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Problems solved by technology

[0002] The traditional supercontinuum generation method is to use 50 femtosecond low-power pulses (pulse energy less than 3nJ) to excite photonic crystal fibers with a length of less than 10 mm, while ensuring that the zero dispersion wavelength of the photonic crystal fibers used is at the generated In the supercontinuum range, for example, to generate a supercontinuum of 600-900 nanometers, the zero dispersion wavelength of the photonic crystal fiber must be in the range of 600-900 nanometers, but the supercontinuum optical pulses generated in this way are low and the power Low, poor optical path stability, unable to excite all nonlinear molecular imaging modalities

In addition, because the femtosecond laser pulse will produce a "time-domain broadening" effect when passing through the optical path, that is, due to the dispersion in the optical path, especially the existence of second-order and higher-order dispersion, the width of the femtosecond pulse on the time axis will change. As the propagation in the optical path increases, the peak power of the femtosecond pulse is greatly reduced, so that the nonlinear effect between the pulse and the sample is weakened or even disappeared

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