"High-Speed Functional OCT with Self-Reconstructive Bessel Illumination at 1300nm "Cedric Blatter, Branislav Grajciar, Christoph M. Eigenwillig, Wolfgang Wieser, Benjamin R. , Biedermann, Robert Huber, Rainer A. Leitgeb
Proc. SPIE, vol. 8091, p. 809104 (2011)
We present a Bessel beam illumination FDOCT setup with FDML buffered swept source at 1300nm. An xtended focus is achieved due to the Bessel beam hat preserves its lateral extend over a large epth range. Decoupling the illumination from the Gaussian detection improves the sensitivity as ompared to double passing the ring filter and nables dark field imaging. Dark field imaging is seful to avoid strong reflexes from the sample´s urface that adversely affect the sensitivity due o the limited dynamic range of high-speed 8bit cquisition cards. Furthermore, Bessel beams xhibit a self-reconstruction property that allows maging even behind obstacles such as hairs on kin. Densely sampled volumes of skin in-vivo with igh lateral resolution are acquired at up to 40kHz A-Scan rate. In addition the possibility of contrasting capillaries with high sensitivity is shown, using inter-B-scan speckle variance analysis. High-speed imaging is of crucial importance for imaging small details since sample motion artifacts are reduced and high sampling can be maintained while increasing the B-Scan rate.
BMO authors (in alphabetic order):
Fourier Domain Mode Locking (FDML): Spectral mode locking in optics and applications
Optical Coherent Ranging and Optical Coherence Tomography (OCT): Imaging and profilometry with rapidly frequency swept laser sources