Powell Lens-based Spectral Domain Line-Field Optical Coherence Tomography system for cellular resolution imaging of biological tissue

A Powell lens is used in a Line-Field Spectral Domain OCT (PL-LF-SD-OCT) system to generate a line-shaped imaging beam with almost uniform distribution of the optical power in the line direction. This design overcomes the severe sensitivity loss (~10 dB) observed along the line length (B-scan width) in LF-OCT systems based on cylindrical lens line generators. The PL-LF-SD-OCT system offers almost isotropic spatial resolution (Δx and Δy ~2 µm, Δz ~1.8 µm) in free space and sensitivity of ~87 dB for 2.5 mW imaging power and 2,000 fps imaging rate, with only ~1.6 dB sensitivity loss along the line length. Images acquired with the PL-LF-SD-OCT system allow for visualization of the cellular and sub-cellular structure of biological tissues.