Waveguide Integrated Label-Free Super-Resolution Microscopy Based On Frequency-Shift Theory

Label-free super-resolution microscopy is an imaging technique that has a wide range of applications and is not easy to damage the sample.Through the different detection methods of the high frequency evanescent field on the surface of the sample,the resolution of traditional microscopy systems has been significantly improved,which promoted the developments of biomedicine,materials science and so on.Recently,label-free super-resolution microscopy has achieved certain results,but it still limited by complex system,the narrow field of view(FOV),the low imaging resolution and image distortion.With the rapid development of micro-nano fabrication process,various optoelectronic devices are gradually moving closer to the miniaturization and integration of nanometer levels.This provides us with a novel idea and direction for the simplified system of label-free super-resolution imaging.Therefore,we proposed a chip-based frequency-shift label-free super-resolution method.It' s a preliminary attempt for the future multi-functional integrated super-resolution imaging chip with high resolution and large FOV.The major research contents and achievements are as follows:(1)Design and fabricate a frequency-shift super-resolution imaging silicon nitride waveguide.A novel method of tunable multi-wavelength illumination was proposed to obtain information of different spectrum ranges of sample.We improved the frequency-shift reconstruction algorithm to achieve one-dimensional etched slots and two-dimensional complex samples super-resolution imaging without distortion,and the imaging resolution reached 160 nm.Besides,aiming at the problem of artifact in the complex sample imaging,we simulated an illumination mode average scheme and eliminated the artifacts successfully.(2)Based on the quartz glass wafer,we proposed a grating multi-angle frequency modulation method.And the two-dimensional VCSEL light source array is designed to couple with the grating etched in the wafer,which produces illumination light with different frequency shifts.A miniaturized circuit board was designed to control the brightness or darkness of the array light.The simple alignment of the array light and the quartz wafer eliminates the complex coupling problem of multi-wavelength illumination scheme,providing an idea for the light source integrated imaging chip.At the same time,information multiplexed algorithms that can be used for system optimization are also studied.In total,we have done a detailed study on the on-chip label-free super-resolution imaging microscopy,and achieved high resolution imaging under a large FOV without distortion,which has a potential for low-cost,large-scale integrated imaging chip manufacturing.