Ultracompact in-line broadband Mach-Zehnder interferometer using a composite leaky hollow-optical-fiber waveguide

Abstract
We report on an ultracompact fiber optic Mach–Zehnder interferometer (MZI) using a novel concatenated structure, single-mode-fiber (SMF)–hollow optical fiber (HOF)-SMF. An optimized air-hole size in the HOF provided two unique optical paths; the leaky waveguide modes through the central air hole and the radiation channel into the silica cladding, which enabled a compact MZI configuration with enhanced optical performances, such as high visibility, high temperature sensitivity, and wide dynamic range.
Funding Information
  • Korea Science and Engineering Foundation (KOSEF) (ROA-2007-000-20041-0, R01-2006-000-11277-0, R15-2004-024-00000-0)
  • Korean Foundation for International Cooperation of Science and Technology (2007-8-0536, 2007-8-1864, and 2007-8-1867)