High frame rate and highly sensitive imaging of refractive index changes on a surface is very promising for studying the dynamics of dissolution,mixing and biological processes without the need for labeling.Here,a hig...High frame rate and highly sensitive imaging of refractive index changes on a surface is very promising for studying the dynamics of dissolution,mixing and biological processes without the need for labeling.Here,a highly sensitive distributed feedback(DFB)dye laser sensor for high frame rate imaging refractometry without moving parts is presented.DFB dye lasers are low-cost and highly sensitive refractive index sensors.The unique multi-wavelength DFB laser structure presented here comprises several areas with different grating periods.Imagingin two dimensions of space is enabled by analyzinglaser light from all areasin parallelwith an imaging spectrometer.With this multi-resonance imaging refractometry method,the spatial position in one direction is identified from the horizontal,i.e.,spectral position of the multiple laser lines which is obtained from the spectrometer charged coupled device(CCD)array.The orthogonal spatial position is obtained from the vertical spatial position on the spectrometer CCD array as in established spatially resolved spectroscopy.Here,the imaging technique is demonstrated by monitoring the motion of small sucrose molecules upon dissolution of solid sucrose in water.The omission of moving parts improves the robustness of the imaging system and allows a very high frame rate of up to 12 Hz.展开更多
基金The authors thank JS Clausen for assistance with electron beam lithography and CLC Smith,KT Sørensen and E Højlund-Nielsen for fruitful discussionsCV acknowledges support from the Danish Research Council for Technology and Production Sciences(Grant No.12-126676).
文摘High frame rate and highly sensitive imaging of refractive index changes on a surface is very promising for studying the dynamics of dissolution,mixing and biological processes without the need for labeling.Here,a highly sensitive distributed feedback(DFB)dye laser sensor for high frame rate imaging refractometry without moving parts is presented.DFB dye lasers are low-cost and highly sensitive refractive index sensors.The unique multi-wavelength DFB laser structure presented here comprises several areas with different grating periods.Imagingin two dimensions of space is enabled by analyzinglaser light from all areasin parallelwith an imaging spectrometer.With this multi-resonance imaging refractometry method,the spatial position in one direction is identified from the horizontal,i.e.,spectral position of the multiple laser lines which is obtained from the spectrometer charged coupled device(CCD)array.The orthogonal spatial position is obtained from the vertical spatial position on the spectrometer CCD array as in established spatially resolved spectroscopy.Here,the imaging technique is demonstrated by monitoring the motion of small sucrose molecules upon dissolution of solid sucrose in water.The omission of moving parts improves the robustness of the imaging system and allows a very high frame rate of up to 12 Hz.