Femtosecond laser multi-modal molecular image system

Abstract

The invention provides a femtosecond laser multi-modal molecular image system. Near-infrared band pulses, the central wavelengths of which are 1010-1100nm and the spectral widths of which are smaller than 25nm, are provided by adopting a near infrared wave band generation device. The near infrared wave band pulses can motivate an optical medium with strong-nonlinearity to generate femtosecond laser pulses with ultrawide optical spectra, and a pulse measuring and compressing control module measures and compensates femtosecond laser pulses to reach chromatic dispersion accumulated by tissue samples, so that the time-domain widening effect is eliminated. The obtained shortest pulses can be acted with the tissue samples to generate various optical spectrum signals of different modals, so that various nonlinear molecular imaging modals are provided.

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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