Design And Fabrication Of Micro F-P Cavity Tunable Filter

A MEMS-based F-P cavity tunable optical filter has a broad application prospects in hyperspectral imaging system.With the increasing enthusiasm of countries around the world,F-P cavity tunable filters have been used extensively in the development of space resources in recent years because of the small volume,high resolution,wide spectrum,and high integration.But the traditional spectral imaging equipment is difficult to meet the needs of high spectral resolution for Remote Sensing Imaging System because of complex structure,big weight and volume,and limited resolution.But the size of array MEMS-based F-P cavity tunable is very small,integration with detector on the semiconductor substrate,makes the whole system simple,more compact structure,lower energy consumption,higher accuracy.Firstly,this paper analysis on the working principle of F-P cavity tunable filter,discusses the way of working and driving type,and discuss the design of the optical film structure of F-P cavity,then make simulation on optical structure,in the optical spectrum of infrared medium wave 3~5?m tuning range,the peak transmittance remained above 80%,and FWHM remain at 110 nm,well meet the design targets;Secondly,make simulation on the structure and mechanical characteristics of F-P filter based on the FEA software,and the L-arm type cantilever structure is established.The simulation results show that,in the process of tuning the biggest angle is 0.002° under the 1.95 V driving voltage,device structure remains good smoothness and stability,L-arm structure applied voltage is only 1.90 V when reaches the 0.5?m displacement,far less than the other structures' driving voltage: X-arm(7.81V),and + circular-arm(8.97V).Then formulate the process scheme,explore the process of device fabrication,and completed the key process node's breakthrough,finally test the structure of device,the results show that the cavity of the device structure has been completely hung up.Some problems in the process of device design and fabrication are discussed,the author analyzes the corresponding reasons,the next step is to explore the improved method.The research goal F-P cavity tunable filter,principles-based on filter spectral and interference imaging,it has great advantage the traditional dispersion spectrometer such as high spectral resolution and high energy utilization,etc.light-duty structure more and more suitable for the aerospace equipment owing to MEMS technology.