Experimental Study And Theoretical Discussion Of The Square Aperture Planar Microlens Array

Recently, as the fabrication of planar microlens with the techniques of lithographic ion-exchange array become more mature, the optical properties of microlens array which buried in the glass substrate is uniformity and unit lens are arranged very well. This type of planar microlens array has many functions such as focusing, imaging, collimation, shunting, index changing and so on. Meanwhile, the capacity of large information storage and the multi channel parallel may be come true with the unit lens which is small enough in diameter and high density. In this paper, we placed emphasis upon to the designing of planar microlens array and the fabrication technology at first. Therefore, we focused on the investigation of the planar microlens array design, production process and performance testing in this paper. From this work, a new type of square aperture planar microlens array was designed and fabricated successfully to achieve the fill factor optimization., and the optical properties of microlens array are further enhanced with improvement of ion-exchange technology and optimization of model design and experimental parameters. So, the fill factor and the photospot efficiency will be improved to an ideal value and this planar microlens array realize a broad application in improving detection the sensitivity, other micro-optical imaging systems and optical processors, etc.In theory, we analyzed the law of ion thermal diffusion of square aperture planar microlens array with method of point source and obtained the index distribution curves which was centrosymmetry from the center of microlens unit to the brink. With this work, we discussed the optical performance of the imaging quality with square-aperture planar microlens arrays.With several experimental steps, we put the substrate into the mixed molten salt with a certain proportion to exchange ion on the glass substrate at different temperature and corroded the 1.0 micron layer of titanium film on the substrate with an appropriate process. Based on the windows width of the sample is 0.2mm and the center distance between adjacency list was 0.8mm, the optical performance parameters (such as refractive index distribution, intercept, number aperture and so on) of sample have been carried on with a more accurate survey by the CCD imaging system and Jas Ming interferometer. However, we got a more satisfactory result that the fill-factor of square aperture planar microlens array is more than 98% and the imaging distortion is very small.With further research on the microlens array, square aperture planar microlens array had the amplification effect on micrograph whose unit size is approximate to the parameters of microlens array. Based on the principle of Moire fringe, we investigated the parameters of micro-structure, velocity and direction of movement, magnification with the micro-graphic array. Therefore, amplification of micrograph,3-dimension dynamic display would be available.