Resolution Improvement in Fabry-Perot Displacement Sensor Based on Fringe Counting Method
Abstract: This paper presents
an improved Fringe Counting Method (FCM) technique in order to enhance the
displacement resolution of a Fabry-Perot Displacement Sensor (FPDS). A simulation
model of a FPDS based on the improved FCM has been developed and simulated for
nanometer displacement range by using MATLAB mathematical software. Unlike
conventional FCM that analyzed the number of fringes produced over one time
period, the improved FCM analyzed the number of fringes for one largest Free
Spectral Range (FSR). In this work, the initial length of Fabry-Perot
Interferometer (FPI) cavity has been set at 75 μm due to limitation of the
machining precision equipment. For the displacement analysis, the improved FCM
technique is used as an algorithm. The research results prove that this FPDS
could detect displacement at 10nm resolution over a working range of 40 nm. It
showed that the improved FCM technique managed to enhance the capability of the
conventional FCM in detecting nanometer displacement.
Author: Nur Izzati Ismail, Nor
Hafizah Ngajikin, Nor Fadzlina Mohd Zaman, Maisarah Awang, Asrul Izam Azmi, Nik
Noordini Nik Abd. Malik, Norazan Mohd Kassim
Journal Code: jptkomputergg140090
