title: Multifrequency swept common-path en-face OCT for wide-field measurement of interior surface vibrations in thick biological tissues.
abstract: Microvibrations that occur in bio-tissues are considered to play pivotal roles in organ function; however techniques for their measurement have remained underdeveloped. To address this issue, in the present study we have developed a novel optical coherence tomography (OCT) method that utilizes multifrequency swept interferometry. The OCT volume data can be acquired by sweeping the multifrequency modes produced by combining a tunable Fabry-Perot filter and an 840 nm super-luminescent diode with a bandwidth of 160 nm. The system employing the wide-field heterodyne method does not require mechanical scanning probes, which are usually incorporated in conventional Doppler OCTs and heterodyne-type interferometers. These arrangements allow obtaining not only 3D tomographic images but also various vibration parameters such as spatial amplitude, phase, and frequency, with high temporal and transverse resolutions over a wide field. Indeed, our OCT achieved the axial resolution of ~2.5 μm when scanning the surface of a glass plate. Moreover, when examining a mechanically resonant multilayered bio-tissue in full-field configuration, we captured 22 nm vibrations of its internal surfaces at 1 kHz by reconstructing temporal phase variations. This so-called "multifrequency swept common-path en-face OCT" can be applied for measuring microdynamics of a variety of biological samples, thus contributing to the progress in life sciences research.
authors.forename: Samuel
authors.initials: S
authors.lastname: Choi
authors.forename: Tomoya
authors.initials: T
authors.lastname: Watanabe
authors.forename: Takamasa
authors.initials: T
authors.lastname: Suzuki
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Nin
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hibino
authors.forename: Osami
authors.initials: O
authors.lastname: Sasaki