Research Projects

Optical Coherence Tomography (OCT) is a non-invasive imaging technique offering high-resolution, cross-sectional visualization of biological tissues and materials. However, conventional OCT systems employing Gaussian beams face limitations such as diffraction-induced degradation, reduced depth of field (DOF), and diminished contrast in scattering media, necessitating frequent refocusing. These challenges significantly constrain OCT’s applicability in deep-tissue or highly scattering environments. This project proposes a novel fiber-based OCT system that integrates structured light beams—Bessel-Gauss (BG), Radially Polarized Gaussian (RPG), Radially Polarized Bessel-Gauss (RPBG), and Radially Polarized Vortex (RPV) beams. Each beam type exhibits unique characteristics: BG beams offer self-healing and non-diffracting behavior, RPG beams enhance axial field interaction, RPBG beams combine extended DOF with strong longitudinal fields, and RPV beams introduce orbital angular momentum (OAM) for deeper sample interaction and improved contrast. These structured beams are expected to significantly enhance OCT imaging in both biological and industrial samples. The central hypothesis is that structured light beams, precisely generated through Two-Photon Polymerization (TPP) fabricated axicons at the fiber tip, can overcome the limitations of Gaussian beams and substantially improve imaging depth, resolution, and contrast in OCT. The project will test this hypothesis by developing and validating a compact OCT system capable of generating and delivering structured beams through optical fibers. The scientific objectives are: i. Design and development of a fiber-based OCT system integrating BG, RPG, RPBG, and RPV beams. ii. Analyze the advantages of structured light beams in improving imaging performance, with a focus on penetration depth, contrast enhancement, and resolution improvements in biological and industrial samples. iii. Comparative analysis of the effectiveness of structured light-based OCT across various biological and industrial samples, assessing its advantages over conventional Gaussian beam-based OCT. The main experiments will include system assembly using supercontinuum and superluminescent diode (SLD) sources, beam shaping via spatial light modulators (SLMs) and radial polarization converters, TPP-based axicon fabrication, and structured beam delivery through fibers. Spectral-domain OCT imaging will be conducted, and performance will be assessed in terms of axial/lateral resolution, penetration depth, and signal-to-noise ratio. If successful, this research will significantly advance the fundamental understanding of structured light–matter interaction within OCT systems and open new avenues for medical diagnostics, endoscopy, and industrial quality control, shaping the future of optical imaging technology.