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Determination of beam incidence conditions based on the analysis of laser interference patterns

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Pages (from-to)2902-2907
Number of pages6
JournalOptik
Volume126
Issue number21
Early online date17 Jul 2015
DOIs
Publication statusPublished - 1 Nov 2015
Publication typeA1 Journal article-refereed

Abstract

Beam incidence conditions in the formation of two-, three- and four-beam laser interference patterns are presented and studied in this paper. In a laser interference lithography (LIL) process, it is of importance to determine and control beam incidence conditions based on the analysis of laser interference patterns for system calibration as any slight change of incident angles or intensities of beams will introduce significant variations of periods and contrasts of interference patterns. In this work, interference patterns were captured by a He-Ne laser interference system under different incidence conditions, the pattern period measurement was achieved by cross-correlation with, and the pattern contrast was calculated by image processing. Subsequently, the incident angles and intensities of beams were determined based on the analysis of spatial distributions of interfering beams. As a consequence, the relationship between the beam incidence conditions and interference patterns is revealed. The proposed method is useful for the calibration of LIL processes and for reverse engineering applications.

Keywords

  • Beam incidence condition, Interference lithography, Laser interference, Modulation period

Publication forum classification

Field of science, Statistics Finland