Coherent anti-stokes raman scattering optical comb spectrum detection method for improving precision

Abstract

The invention discloses a coherent anti-stokes raman scattering (CARS) optical comb spectrum detection method for improving the precision. The method comprises the steps of: after two femtosecond optical comb generators as a pumping-detecting light source and a stokes light source of a CARS system pass a CARS spectral measurement system, performing beat frequency and double-optical comb optical heterodyne detection on generated anti-stokes signal light and reference optical combs; eliminating the interference introduced by pumping light by utilizing a polarization dependent balance detection technology at a detecting part so as to realize the quick and real-time CARS optical spectrum detection with high sensitivity and high frequency resolution precision. The method provided by the invention can be used for effectively improving the resolution precision of spectral measurement, realizing the high-precision optical comb imaging within a wide spectral range, effectively inhibiting the environmental noises, eliminating the non-resonant background noise introduced by the pumping light, improving the time and frequency resolution precision and realizing the quick and real-time spectral detection.

Description

technical field [0001] The invention belongs to the technical field of laser spectroscopy, and in particular relates to a novel method for realizing high-precision coherent anti-Stokes Raman scattering light comb spectral detection by using a femtosecond optical frequency comb. Background technique [0002] The Coherent Anti-Stokes Raman Scattering (CARS) process has long been used as a spectral detection method with high sensitivity and high spectral resolution, and is applied in physics, chemistry, material science, medicine, etc. In many research fields such as biology, biology and life sciences. Through the study of CARS spectrum, people can obtain more qualitative and quantitative information about the composition of matter, such as the energy level structure of atoms, molecules, etc., electronic configuration, molecular geometry, reaction kinetics and other aspects of material structure. Knowledge. Compared with other existing microscopic imaging technologies, CARS s...

AI Technical Summary

Problems solved by technology

The polarization detection scheme requires the light source to be in a linearly polarized state, and the polarization angle between the pump light and the Stokes light is precisely controlled; the time-resolved detection uses an ultrashort pulse laser as the excitation light. The time delay is introduced between laser beams to eliminate noise, and its accuracy depends on the bandwidth of the laser and the linewidth of the spectrum; the method of phase control and shaping uses a spatial light modulator to introduce phase mismatch between different spectral components to suppress background noise, But its spectral resolution is limited by the resolution of the spatial modulator within the spectral bandwidth of the laser

[0004] In addition, the super-resolution optical imaging technology developed so far cannot realize wide-spectrum and high-precision spectral detection and spectral imaging, which greatly limits the major basic problems of existing technologies in the in situ recognition of cell molecules and the characterization of cell molecule maps. applications; in high-end equipment manufacturing industrial applications and other fields, it is necessary to realize non-contact detection and spatial high-resolution measurement of a large field of view at the same time. Usually, the spatial resolution of large-field optical imaging is low, while the observation of microscopic optical imaging The field of view is small, and the two cannot be unified under the existing technical framework; in order to obtain high-precision measurement and high-sensitivity trace analysis, it usually needs to be realized by long-term time integration of the signal, and it is impossible to obtain fast and real-time Measurement results; the measurement accuracy of the existing spectral imaging analysis equipment depends on the resolution accuracy of the spectrometer, which requires the use of complex and expensive spectral measurement equipment, resulting in a significant increase in the complexity and cost of the spectral imaging analyzer

[0005] In summary, the current CARS spectral measurement and detection technology still has deficiencies

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