Dynamic adjustment method for focal spots based on fluid micro lens with gradually changing refraction index

Abstract

The invention relates to a dynamic adjustment method for focal spots based on a fluid micro lens with a gradually changing refraction index, which comprises the steps that (1) core layer fluid and wrapping layer fluid are injected into a microcavity, wherein the core layer fluid and the wrapping layer fluid only have diffusion and convection motions therebetween rather than chemical reactions, the wrapping layer fluid evenly surrounds the core layer fluid, relative slippage does not exist between the core layer fluid and the wrapping layer fluid, and the core layer fluid and the wrapping layer fluid are two types of fluid with different refraction indexes; (2) the beam propagation direction of the micro lens is consistent with the fluid flowing direction; (3) the fluid diffusion process is controlled through adjusting the flow rate, the temperature, the concentration or the micro fluid type, and adjustment and control for spatial distribution of the refraction indexes in the microcavity is realized; and (4) the refraction index of a central area of refraction index distribution in the cavity is the highest and is a constant value when the average flow rate and the core layer flow rate are greater than a high flow rate threshold, and emergent light focal spots are formed along with gradually changing refraction index distribution at a marginal area of the microcavity. The method provided by the invention carries out dynamic adjustment on the focal spots effectively, and is good in flexibility.

Description

technical field [0001] The invention belongs to the field of optical microlenses, in particular to a method for dynamically adjusting a focal spot based on a fluid microlens with a gradient refractive index. Background technique [0002] Existing fluid microlenses usually use liquid-liquid lenses, which are generally off-chip focusing fluid microlenses, which cannot realize the integration of on-chip systems. Recently, Professor Whitesides' group developed a microlens that can dynamically adjust the curvature of the liquid-liquid lens surface, realizing the adjustable focal length in the chip (Tang, Sindy K.Y.; Stan, Claudiu A.; Whitesides, George M, Dynamically reconfigurable liquid-core liquid-cladding lens in a microfluidic channel, Lab.Chip.,8(2008):395-401, dynamically adjustable liquid core layer-liquid cladding lens based on microfluidic channel, laboratory on a chip, 8(2008 ):395-401). However, the microlens realized by the liquid-liquid lens interface needs a high...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the shortcomings of the existing fluid microlenses that cannot dynamically adjust the focal spot and have poor flexibility, the present invention provides a dynamic adjustment method for the focal spot based on the gradient index fluid microlens that can effectively and dynamically adjust the focal spot and has good flexibility

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