Spectral signal processing in swept source optical coherence tomography

OCT (optical coherence tomography) is generally regarded as the 6th imaging modality. This light-based system ideally suits for bio-medical diagnostic imaging applications. Outperforming to the time-domain OCT, Swept-Source OCT (SSOCT) is termed as the second generation OCT, in which, usually, thousand of individual wavelengths are sent into the system in a time sequence. The backscattered or back reflected light from the testing sample is collected by a sensor corresponding to each wavelength. The thousand received signals actually represent the Fourier coefficients in the spectrum domain. However, these coefficients only have real positive values as the sensor can only produce intensity signal. This paper describes the signal processing issues related with this intensity spectrum. Various filters, high-pass, low-pass and band-pass; spectrum decomposition; spectrum combination are discussed and demonstrated. A method for spectral synthesis of multiple light sources is presented.Peer reviewed: YesNRC publication: Ye