Time-frequency analysis for an efficient detection and localization of side-coupled cavities in real photonic crystals

We propose and demonstrate here the high efficiency of concurrent time and frequency analysis to detect and unambiguously identify the coupled cavities in real photonic crystals containing imperfections and/or process-induced disorder. This procedure when applied to reflectograms recorded using phase-sensitive optical low-coherence reflectometry allows a straightforward and complete assessment of cavities (spectral and spatial localization in addition to photon lifetime) over a wide spectral range. Considering such a reflectogram (recorded in 2 s), we show that this procedure greatly eases the evaluation of cavities under guiding conditions in real photonic crystals by discriminating their signature from the in-plane scattering induced by disorder.