Abstract
High-power ultra-broadband sources such as a supercontinuum are very attractive in optical coherence tomography (OCT) and optical coherence-domain reflectometry (OCDR) due to their very high resolution potential. However, the large and extensive coherence-function sidelobes typical of such sources preclude their use in conventional OCDR and OCT systems. In addition, device or sample dispersion over such broad band-widths may also significantly limit the achievable performance. Here we describe a novel experiment using a supercontinuum source with a static Michelson interferometer to perform OCDR at 1.55 μm. Quadrature spectral detection is used to maximise the scanning range and to allow direct compensation for both the undesirable spectral shape of the source and for the dispersion in the system. Such a non-scanning-interferometer approach is an interesting possible alternative for very broadband, ultra-high resolution OCT systems. We demonstrate that an otherwise obscured small reflection next to a large reflection can be revealed by appropriately weighting the data to reshape the supercontinuum spectrum and compensate for dispersion. Significant reduction of the supercontinuum coherence function sidelobes is achieved, and a resolution in air of 7 μm (FWHM) is obtained, or less than 5 μm in media of refractive index 1.45.