Light Field Regulation And Optical Imaging Applications

A light wave contains multiple kinds of optical information:amplitude,phase,and polarization.Light field regulation technology can regulate these information to achieve many applications,such as particle acceleration,laser fabrication,beam shaping,optical tweezers,holographic projection,optical imaging,and so on.Focusing regulation is used for the field of optical imaging.However,recently,regulated light fields still have many problems need to be solved.For example,focusing vortices are circular only,and are all on the single focal plane;focusing multiple foci have low intensities so that they cannot achieve high contrast imaging;focusing foci with the large focal depths are located at the single axial area only.Based on the above problems,this thesis launches studies on light field regulation and optical imaging applications.The main contents are as follows,(1)Two kinds of spiral zone plates are proposed to generate polygonlike vortex beams.For the modified petal-like spiral zone plate,it is proved in the simulations and experiments that the modified petal-like spiral zone plates have the single polygon-like vortex beams with the tailorable sizes,topological charges and shapes,and the interference method is used to identify the topological charges of the polygon-like vortex beams.For the modified interfering vortex spiral zone plate,it is proved numerically and experimentally that the modified interfering vortex spiral zone plates have the two polygon-like vortex beams with the designed shapes and topological charges.The plane wave phases modulate the rotation of the inner polygon-like vortex beams,and the topological charges of two polygon-like vortex beams can be identified by the interference method.(2)A modified m-bonacci spiral photon sieve is proposed to generate two equal-intensity vortices with the same size at two focal planes.The widths of the connected high transmittance spiral zones and the number of added spiral zone pairs have influence on the intensities and positions of twin vortices,respectively.Optimized pinhole sizes are used to produce the two vortices with equal and high intensity.It is proved in the simulations and experiments that the modified m-bonacci spiral photon sieve has the two vortices with equal intensity and the same size,and achieves the biplanar edge enhanced imaging.(3)Compared with the conventional aperiodic zone plates,the proposed generalized composite aperiodic zone plates can enhance the focal intensities for achieving high contrast imaging.The generalized composite aperiodic zone plate consists of the conventional aperiodic zone plate and radial aperiodic zone plate.It is proved numerically and experimentally that the generalized composite aperiodic zone plates can generate higher-intensity foci.It is proved in the simulations that the modulation transfer function curve of the generalized composite aperiodic zone plate is above that of the conventional aperiodic zone plate,which indirectly illustrates that the generalized composite aperiodic zone plate can achieve high contrast imaging.Moreover,it is proved experimentally that the generalized composite aperiodic zone plates can produce the higher contrast images.(4)Two kinds of zone plates are proposed to produce the two long focal-depth foci with the different and same sizes respectively for achieving the extended bifocal depth imaging.For Fibonacci Pearcey zone plates,when the exponent and modulation parameter of the Pearcey function and the focal length of the Pearcey beam have the appropriate values,the two foci have the extended focal depths and the ratio of bifocal positions is close to the golden mean.Moreover,the extended bifocal depth imaging is proved by the simulations and experiments.For modified generalized composite kinoform Fibonacci lenses,the generalized composite kinoform Fibonacci lenses have the two foci with higher intensity than the conventional kinoform Fibonacci lenses.When the gradient phases have the appropriate values and are very big,its bifocal sizes are the same basically.The GSW(Weighted GerchbergSaxton)algorithm can extend its bifocal depths.It is proved with the simulations and experiments that modified generalized composite kinoform Fibonacci lenses have the two main foci with the extended focal depths and same sizes approximately,and can achieve the same-size extended bifocal depth imaging.