| Vortex light is a special structured light field,a twisted beam with a phase or polarization singularity,and its phase is spiral.Such a beam profile can be twisted around the axis of travel like a corkscrew,and its central intensity is zero.According to the orbital angular momentum and vortex phase carried by the vortex light itself,it can be applied to many fields:using the orbital angular momentum of the vortex light,it can be transmitted to the particles to manipulate the particles,such as capturing and translating the particles;Different orbital angular momentum will not crosstalk with each other,and vortex light can be used in optical communication to improve the capacity of the optical communication system;using its angular phase rotation characteristics,it can be applied to spiral phase filters in imaging,thereby improving the edge profile of imaging Resolution.This master's degree thesis focuses on the regulation and imaging technology of vortex light,mainly doing the following two aspects of research:1.A binary-code-compatible light field control system was proposed for the first time.This system can be used to generate vortex light and vector light with adjustable orders.The system order is controlled by a binary electrical signal.The system is divided into a bit unit and a symbol unit.The bit unit is composed of a liquid crystal wave plate and a liquid crystal vortex wave plate with different orders.The symbol unit is composed of two liquid crystal wave plates,and several bit units are arranged in a sandwich structure.The order of the number satisfies binary coding(1,2,4,8...).By controlling the voltage of the N bit cells and the symbol cells,the controllable order is-2~N+1?2~N-1.This system can be used as modulation and demodulation equipment in vortex and vector optical multiplex communication.2.An experimental study of the application of non-collinear optical parameter magnification to spiral phase contrast microscopy imaging of biological tissues is proposed.The SPC OPA idler imaging for biological tissues has been successfully implemented.The device includes optical parameters on the Fourier plane.The amplifier's 4f optical imaging system,by using a vortex laser beam to pump the amplifier at an intensity of 2 GW/cm2,a significant EEE will appear in the wavelength-converted idler image,which allows our setup to be clearly captured The structure of the phase target:frog egg cells,herbal tissues,and onion epidermis,fine to a few microns,can be improved if using higher magnification MS.The OPA gain is about 6.0 and increases with increasing pumping intensity.If it is pumped with a femtosecond laser,it can reach hundreds of gigawatts per square centimeter.High gain allows performing optical imaging with weak illumination signals,which is often the first choice for non-destructive imaging.At the same time,the high gain also brings a large OPA bandwidth,which helps to obtain the high spatial resolution of OPA imaging.In addition,the design of the non-collinear configuration separates the idling beam from the illumination signal and the strong pump in space,thereby effectively avoiding the background noise of both.It can be concluded from the above description that our device combines SPF with high gain,high spatial resolution,and nonlinear frequency conversion,so it can be used for wavelength conversion micro-optical imaging with spatial resolution down to the micron level.Our experimental results show that the design provides a powerful tool for non-destructive biological tissue imaging. |
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