Research On Design And Performance Of Micro Lens In Fiber Integral Field Unit

The optical-fiber-based Integral Field Unit(IFU)is a very important device for the imaging spectroscopy,especially in astronomy.Its capability of obtaining spectra across the surface of an extended object simultaneously is significant.Also,its advantage is speed detection,measurement of high precision,and limit the influence of the environmental impact is small.According to its structure can be divided into three kinds: lens array,combination of fibers and lens array,image slicing.With this topic focuses on the advantage of the three types of the most obvious,the most effective one,the method of fibers and lens array.In order to improve the spatial resolution of the observation by the target,the devices need a lot of optical fiber.This topic is committed to the research of thousandsof optical fibers in IFU,and found the influence factors of the means of production,then seek out ways to avoid.IFU can realize the process of the FASOT system information integration in the input spectrum tester for testing analysis,so its performance will have a significant impact to the entire observation result.This paper select made of micro lens and fiber bundle IFU type,the essential reason of its loss is optical efficiency of optical fiber selected,FRD and micro lens and optical fiber coupling.The ratio of the fiber refers to the angle betweenthe incident or shoot lightsand axis,the ideal assumptions is these two rates are equal,but because of the environmental impact and the properties the output light angleof the fiber get bigger emergent,light dispersion,and this phenomenon is called the FRD.Severe focal degeneration can make the image distortion,thereby causing loss to the light.IFU system often use a large number of optical fiber,FRD will causes a huge loss,even affect the authenticity of the results.And IFU system as the transmission of data information optics also need good light passing rate,receive maximum optical information from the telescope,then transfer to the spectrum analyzer with minimum loss,ensure the integrity of the data.Only use optical fiber can also build a IFU system independently,but the gap between optical fiber and optical fiber circular structure will make a dark space,causes the IFU accept a very low light efficiency,so the paper chose to use micro lens to convergent beam,this structure has greatly increased the fiber optic light rate,avoid the loss.Because of micro lens and fiber material is small,so those two coupling will lead to loss,paper listed three types of deviation,it is concluded that the lateral migration will cause larger loss.In order to avoid the influence of the above three conditions on the system,choose special micro lens and optical fiber to guarantee the good properties,designed a unique pore structure to improve the production efficiency of fiber bundle arrays and the unique cross mark to reduce alignment loss of micro lens array with fiber.In this paper,we aim to build an IFU for the FASOT(Fiber Arrayed Solar Optical Telescope)system.Under circumstances of good measurement accuracy?high transmission efficiencyandfocal ratio,we complete the 11×11×2IFU.