Spectroscopic identification of materials with calibrated full-field optical coherence tomography in the visible range

Antoine Morin (1) , Jean-Marc Frigerio (2, 1)

1 INSP - Institut des Nanosciences de Paris
2 BioGeCo - Biodiversité, Gènes & Communautés

For twenty years Optical Coherence Tomography (OCT) has been interested in imaging in turbid media. Recently, conventional OCT has been extended to spectroscopic investigation (SOCT). For a full-field OCT configuration in the visible range, we show that the interference conditions are not equal in the whole field of view: the effective numerical aperture depends on the observation point. This results in a spectral shift towards higher wavelengths of the OCT spectra, leading to errors in spectroscopic analysis. We propose a general calibration method for SOCT measurements which has been tested within a protocol, to perform spatially-resolved spectroscopic identification of material by OCT. Firstly we measure the reflectivity of a plane gold sample, corresponding closely to the measurement made with a spectrometer. Then we successfully identify the reflectivity of gold in a mixed sample (silicon and gold).

Mots clés: Optical coherence tomography; Spectroscopy; Calibration; Micro-spectrometry; Identification

Domaines: Matière Condensée [cond-mat]

Antoine Morin, Jean-Marc Frigerio. Spectroscopic identification of materials with calibrated full-field optical coherence tomography in the visible range. OPTICAL MICRO- AND NANOMETROLOGY IV, 2012, 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA, Unknown Region. ⟨10.1117/12.921539⟩. ⟨hal-01236769⟩