High-quality 3-D imaging with multimegahertz OCT

Researchers demonstrated high-quality 3-D imaging with multimegahertz optical coherence tomography (OCT). It was demonstrated OCT was imaging modality that can provided three-dimensional (3-D) information on the scattering properties of biological samples. OCT was able to deliver high-quality images due to a nearly shot noise-limited sensitivity of at least 98 dB and an axial resolution of roughly 10 μm in tissue. e high speed also created opportunities for completely new volumetric averaging protocols for speckle reduction, along with future volumetric OCT at video rate. A specially developed high speed filter enabled researchers to build the fastest Fourier domain mode-locked (FDML) laser, running at a 5.2-MHz sweep repetition rate over an 80-nm tuning range at 1,300 nm. The OCT imaging speed was significantly increased for 3-D acquisition by using four distinct imaging spots on the sample in parallel.