Femtosecond digital in-line holography with the fractional Fourier transform: application to phase-contrast metrology |
| |
Authors: | M. Brunel H. Shen S. Coetmellec D. Lebrun K. Ait Ameur |
| |
Affiliation: | (1) Coherent Optics Division, Central Scientific Instruments Organisation, Sector 30, Chandigarh, 160 030, India;(2) Department of Applied Physics, Guru Jambheshwar University of Science & Technology, Hisar, 125 001, India; |
| |
Abstract: | The possibility to analyze transparent phase objects using femtosecond digital in-line holography is demonstrated. We show that the diffraction patterns produced by the diffraction of 20-fs pulses by pure phase objects can be advantageously processed by using the fractional Fourier transform. The optimal fractional orders lead to the longitudinal location of the phase object while the analysis of the reconstructed patterns leads to its diameter and to the value of the phase shift. Simulations and experimental results are in good concordance. This work shows new important applications of these reconstruction techniques in the domain of digital phase-contrast metrology. We further show that the use of femtosecond pulses results in a significant reduction of coherent noise. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|