Measuring Optical Phase Singularities at Subwavelength Resolution

• Published in: Journal of Optics A: Pure and Applied Optics, vol. 6, p. 189-196
• Publication date: 2004

We will present experimental and theoretical studies of optical fields with subwavelength structures, in particular phase singularities and coherent detection methods with nanometric resolution. An electromagnetic field is characterized by an amplitude, a phase and a polarization state. Therefore, experimental studies require coherent detection methods, which allow one to measure the amplitude and phase of the optical field with subwavelength resolution. We will present two instruments, a heterodyne scanning probe microscope (heterodyne SNOM) and a high resolution interference microscope (HRIM). We will review some earlier work using the heterodyne SNOM, in particular the measurement of phase singularities produced by a 1 μm pitch grating with 10 nm spatial sampling. Using the HRIM we have investigated the intensity and phase distributions (with singularities) in the focal region of microlenses. The measurements are compared with the results calculated by rigorous diffraction theory.

Reference

• LOB-ARTICLE-2009-001
• doi:10.1088/1464-4258/6/5/009

Record created on 2009-01-06, modified on 2017-05-10