Abstract

We demonstrate that, under suitable conditions, subwavelength feature variations of an object can affect the corresponding far-field diffraction pattern in a measurable way. We present an experiment in which width variations of less than $1/100$ of the wavelength are measured with a slit whose width is 100 times the wavelength. Integral and differential intensity measurements in the far field are fully consistent with standard diffraction theory even in the subwavelength variation regime. In particular, slit modulations of 6 nm with a wavelength of 670 nm are shown to follow theoretical calculations within the experimental sensitivity of $\sim {10}^{-5}$.

© 2002 Optical Society of America

Characterization of the signature of subwavelength variation from far-field irradiance

Shu-Chun Chu and Jyh-Long Chern
Opt. Lett. 29(10) 1045-1047 (2004)

Detection of subwavelength slit-width variation with measurements in the far field by use of an embedded-aperture interferometer configuration

Shu-Chun Chu and Jyh-Long Chern
J. Opt. Soc. Am. A 22(2) 335-341 (2005)

Retrieving two-dimensional information of the subwavelength variation from far-field irradiance

Shu-Chun Chu and Jyh-Long Chern
J. Opt. Soc. Am. A 23(10) 2471-2475 (2006)

Identifying the subwavelength-aperture-width variation in the far field with tunable asymmetrically-embedded-aperture interferometer configuration

Shu-Chun Chu and Jyh-Long Chern
J. Opt. Soc. Am. A 22(8) 1600-1606 (2005)

Absolute determination of the wavelength and spectrum of an extreme-ultraviolet beam by a Young’s double-slit measurement

R. A. Bartels, A. Paul, M. M. Murnane, H. C. Kapteyn, S. Backus, Y. Liu, and D. T. Attwood
Opt. Lett. 27(9) 707-709 (2002)