Digital Image Processing Of Frinji Interference Pattern To Determine The Thickness Of Transparent Mica In Micro Orde

Abstract

Abstrak Penelitian ini bertujuan untuk memanfaatkanpengolahan citra digital pergeseran frinji pola interferensi untuk menentukan ketebalan mica transparan. Hasil pengukuran ketebalan bahan tipis akan dibandingkan dengan hasil yang diperoleh dari pengukuran menggunakan mikrometer sekrup. Bahan yang digunakan adalah mica transparan. Mica transparan diletakkan di salah satu lengan interferometer Michelson, kemudian sampel tersebut diputar perlahan dengan variasi sudut 1° sampai 7°. Hasil pergeseran pola frinji direkam, kemudian dengan bantuan pengolahan citra digital citra pola frinji diubah menjadi citra greyscale (keabuan) untuk memudahkan analisis jumlah pergeseran pola frinji untuk setiap variasi sudut. Setelah didapatkan pergeseran pola frinji (N), maka ketebalan mica transparan (t) dapat ditentukan. Hasil perbandingan pengukuran ketebalan mica transparanpada orde mikro menggunakan metode interferensi dengan bantuan pengolahan citra digital dan dengan mikrometer sekrup tidak jauh berbeda. Pengukuran dengan metode interferometer menghasilkan tebal mica transparan (0,067±0,003) mm, sedangkan dengan menggunakan mikrometer sekrup diperoleh (0,07±0,01) mm. Pengolahan citra digital pada frinji pola interferensi terbukti dapat meningkatkan ketelitian pengukuran. Kata kunci: mica transparan, interferometer Michelson, pola frinji, pengolahan citra digital. Abstract The objective of this study was to utilize digital image processing to study the shifting of interference patterns to determine the thickness of transparent mica. In this study the result of measurement of mica thickness would be compared with the result obtained from measurement using screw micrometer. The material used was transparent mica. A sheet of transparent mica was placed in one of Michelson's interferometer arms, then the sample was rotated slowly with angle variations of 1 ° to 7 °. The results of the fringe pattern shift were recorded, then by the help of digital image processing, the image of the fringe pattern was transformed into a greyscale image to facilitate the analysis of the number of fringe patterns shifts for each angle variation. Having obtained the number of fringe shift (N), the transparent mica thickness (t) could be determined.The results of measurement of transparent mica thickness in micro order using inteference method by the help of digital image processing and by screw micrometer were not much different. Measurements using interferometer method resulted in a transparent mica thickness of (0.067 ± 0.003) mm, while by using a screw micrometer obtained transparent mica thickness of (0.07 ± 0.01) mm. Digital image processing on fringe interference patterns proved to improve the precision of measurements. Keywords: transparent mica, Michelson interferometer, fringe pattern, digital image processing.