To address the current limitations of time-gated Raman spectroscopy,specifically its narrow spectral range and low spectral resolution,and simultaneously acquire Raman and fluorescence life-time images,we have develop...To address the current limitations of time-gated Raman spectroscopy,specifically its narrow spectral range and low spectral resolution,and simultaneously acquire Raman and fluorescence life-time images,we have developed a Fourier-transform photon counting spectroscopy platform.A Mach-Zehnder interferometer employing a high accuracy linear motor stage was combined with photon-counting avalanche diodes and time-tagged acquisition,allowing to sort photons into a matrix of stage positions determined using their coarse arrival time with 50 ns steps of the excitation laser repetition period,and a fine arrival time of 80 ps resolution relative to the excitation pulse of 100 ps duration.The instrument achieves a time resolution of 547 ps,a wide spectral range of−1000 to 10,000 cm−1 Raman shift from the excitation at 532 nm wavelength,and a high spectral resolution of 0.05 cm−1.For experimental validation,we used fluorescently coated silicon wafers and fluorescent plastic microspheres.Raman signal was observed during the laser excitation pulse within the time-resolution,while fluorescence signals dominate afterwards.The results confirm that the instrument can effectively separate Raman and fluorescence signals.展开更多
基金Funded by Chinese Academy of Sciences President’s International Fellowship Initiative.Grant No.2022VBA0028.
文摘To address the current limitations of time-gated Raman spectroscopy,specifically its narrow spectral range and low spectral resolution,and simultaneously acquire Raman and fluorescence life-time images,we have developed a Fourier-transform photon counting spectroscopy platform.A Mach-Zehnder interferometer employing a high accuracy linear motor stage was combined with photon-counting avalanche diodes and time-tagged acquisition,allowing to sort photons into a matrix of stage positions determined using their coarse arrival time with 50 ns steps of the excitation laser repetition period,and a fine arrival time of 80 ps resolution relative to the excitation pulse of 100 ps duration.The instrument achieves a time resolution of 547 ps,a wide spectral range of−1000 to 10,000 cm−1 Raman shift from the excitation at 532 nm wavelength,and a high spectral resolution of 0.05 cm−1.For experimental validation,we used fluorescently coated silicon wafers and fluorescent plastic microspheres.Raman signal was observed during the laser excitation pulse within the time-resolution,while fluorescence signals dominate afterwards.The results confirm that the instrument can effectively separate Raman and fluorescence signals.
