Ultraviolet(UV)imaging enables a diverse array of applications,such as material composition analysis,biological fluorescence imaging,and detecting defects in semiconductor manufacturing.However,scientific-grade UV cam...Ultraviolet(UV)imaging enables a diverse array of applications,such as material composition analysis,biological fluorescence imaging,and detecting defects in semiconductor manufacturing.However,scientific-grade UV cameras with high quantum efficiency are expensive and include complex thermoelectric cooling systems.Here,we demonstrate a UV computational ghost imaging(UV-CGI)method to provide a cost-effective UV imaging and detection strategy.By applying spatial–temporal illumination patterns and using a 325 nm laser source,a singlepixel detector is enough to reconstruct the images of objects.We use UV-CGI to distinguish four UV-sensitive sunscreen areas with different densities on a sample.Furthermore,we demonstrate dark-field UV-CGI in both transmission and reflection schemes.By only collecting the scattered light from objects,we can detect the edges of pure phase objects and small scratches on a compact disc.Our results showcase a feasible low-cost solution for nondestructive UV imaging and detection.By combining it with other imaging techniques,such as hyperspectral imaging or time-resolved imaging,a compact and versatile UV computational imaging platform may be realized for future applications.展开更多
Miniaturized on-chip spectrometers with small footprints,lightweight,and low cost are in great demand for portable optical sensing,lab-on-chip systems,and so on.Such miniaturized spectrometers are usually based on eng...Miniaturized on-chip spectrometers with small footprints,lightweight,and low cost are in great demand for portable optical sensing,lab-on-chip systems,and so on.Such miniaturized spectrometers are usually based on engineered spectral response units and then reconstruct unknown spectra with algorithms.However,due to the limited footprints of computational on-chip spectrometers,the recovered spectral resolution is limited by the number of integrated spectral response units/filters.Thus,it is challenging to improve the spectral resolution without increasing the number of used filters.Here we present a computational on-chip spectrometer using electrochromic filter-based computational spectral units that can be electrochemically modulated to increase the efficient sampling number for higher spectral resolution.These filters are directly integrated on top of the photodetector pixels,and the spectral modulation of the filters results from redox reactions during the dual injection of ions and electrons into the electrochromic material.We experimentally demonstrate that the spectral resolution of the proposed spectrometer can be effectively improved as the number of applied voltages increases.The average difference of the peak wavelengths between the reconstructed and the reference spectra decreases from 1.61 nm to 0.29 nm.We also demonstrate the proposed spectrometer can be worked with only four or two filter units,assisted by electrochromic modulation.In addition,we also demonstrate that the electrochromic filter can be easily adapted for hyperspectral imaging,due to its uniform transparency.This strategy suggests a new way to enhance the performance of miniaturized spectrometers with tunable spectral filters for high resolution,low-cost,and portable spectral sensing,and would also inspire the exploration of other stimulus responses such as photochromic and force-chromic,etc,on computational spectrometers.展开更多
基金National Natural Science Foundation of China(62075004,62275010,11804018)China Postdoctoral Science Foundation(2022M720347,2022TQ0020)+2 种基金Beijing Municipal Natural Science Foundation(4212051,1232027)International Postdoctoral Exchange Fellowship Program(YJ20220241,YJ20220037)Fundamental Research Funds for the Central Universities。
文摘Ultraviolet(UV)imaging enables a diverse array of applications,such as material composition analysis,biological fluorescence imaging,and detecting defects in semiconductor manufacturing.However,scientific-grade UV cameras with high quantum efficiency are expensive and include complex thermoelectric cooling systems.Here,we demonstrate a UV computational ghost imaging(UV-CGI)method to provide a cost-effective UV imaging and detection strategy.By applying spatial–temporal illumination patterns and using a 325 nm laser source,a singlepixel detector is enough to reconstruct the images of objects.We use UV-CGI to distinguish four UV-sensitive sunscreen areas with different densities on a sample.Furthermore,we demonstrate dark-field UV-CGI in both transmission and reflection schemes.By only collecting the scattered light from objects,we can detect the edges of pure phase objects and small scratches on a compact disc.Our results showcase a feasible low-cost solution for nondestructive UV imaging and detection.By combining it with other imaging techniques,such as hyperspectral imaging or time-resolved imaging,a compact and versatile UV computational imaging platform may be realized for future applications.
基金supported by the National Natural Science Foundation of China(U23A20481,62075004,11804018,62275010)Beijing Municipal Natural Science Foundation(1232027)+2 种基金China Postdoctoral Science Foundation(2022M720347,2024T171115)the International Postdoctoral Exchange Fellowship Program(YJ20220241)the Fundamental Research Funds for the Central Universities.
文摘Miniaturized on-chip spectrometers with small footprints,lightweight,and low cost are in great demand for portable optical sensing,lab-on-chip systems,and so on.Such miniaturized spectrometers are usually based on engineered spectral response units and then reconstruct unknown spectra with algorithms.However,due to the limited footprints of computational on-chip spectrometers,the recovered spectral resolution is limited by the number of integrated spectral response units/filters.Thus,it is challenging to improve the spectral resolution without increasing the number of used filters.Here we present a computational on-chip spectrometer using electrochromic filter-based computational spectral units that can be electrochemically modulated to increase the efficient sampling number for higher spectral resolution.These filters are directly integrated on top of the photodetector pixels,and the spectral modulation of the filters results from redox reactions during the dual injection of ions and electrons into the electrochromic material.We experimentally demonstrate that the spectral resolution of the proposed spectrometer can be effectively improved as the number of applied voltages increases.The average difference of the peak wavelengths between the reconstructed and the reference spectra decreases from 1.61 nm to 0.29 nm.We also demonstrate the proposed spectrometer can be worked with only four or two filter units,assisted by electrochromic modulation.In addition,we also demonstrate that the electrochromic filter can be easily adapted for hyperspectral imaging,due to its uniform transparency.This strategy suggests a new way to enhance the performance of miniaturized spectrometers with tunable spectral filters for high resolution,low-cost,and portable spectral sensing,and would also inspire the exploration of other stimulus responses such as photochromic and force-chromic,etc,on computational spectrometers.
