"Optical Coherence Tomography Imaging with k-Space Linear Fourier Domain Mode Locked Lasers"C. Eigenwillig, B. Biedermann, R. Huber
Conference on Lasers and Electro-Optics/Quantum-Electronics and Laser Science Conference and Photonic Applications Systems Technologies CFM2 (2008)
The introduction of frequency domain (FD) detection techniques in optical coherence tomography (OCT) enabled a dramatic increase in imaging speed while still maintaining high system sensitivity.[1-4] Spectrometer based FDOCT systems are already widely used, especially for ophthalmic applications in the 800 nm wavelength range. Alternatively, the application of OCT systems based on rapidly swept narrow band light sources (swept source OCT) [5-7] offers the advantages of dual balanced detection, longer ranging depth and potentially higher imaging speeds. The advent of Fourier Domain Mode Locked (FDML) lasers  as swept light sources for OCT enabled high imaging speeds of up to 370.000 lines/s, combined with good phase stability  and long ranging depths . However, a general disadvantage of all FD-OCT systems, including FDML based devices, is the requirement to resample the detected OCT fringe signals prior to Fourier transformation to provide data evenly sampled in optical frequency. Spectrometer based FD-OCT systems and swept source OCT systems based on light sources with polygon scanners  exhibit small non-linearity, but they still require correction for the frequency to wavelength relation ν = c/λ. Swept source OCT systems based on mechanically resonant filters  or typical FDML lasers  show an even more pronounced non-linear sweep operation due to the sinusoidal excitation of the filter. The step of signal-resampling prior to Fourier transformation involves high computational effort, potentially introduces additional noise and can yield lower sensitivity due to information loss in the oversampled parts of the spectrum.
BMO authors (in alphabetic order):
Optical Coherent Ranging and Optical Coherence Tomography (OCT): Imaging and profilometry with rapidly frequency swept laser sources
Fourier Domain Mode Locking (FDML): Spectral mode locking in optics and applications