Construct structured illumination with optical fibres for microscopic imaging

Abstract

Optical microscope has been a powerful instrument for us to enter the world of Lilliput as Gulliver did since its invention. In late-19th century, Abbe and Rayleigh derived the resolution limit of optical microscope, which is about a half of wavelength used for illumination, implies we can only see details down to nanometre level using visible light and it is unnecessary to increase magnification power beyond this limit. Super-resolution microscopy(SRM) are techniques which can achieve an effective resolution better than diffraction limit stated by Abbe and Rayleigh with specially-designed optics and image processing. Structured Illumination Microscopy(SIM) is one of SRM techniques and it has two core elements in experiment: creating a structured illumination by interfering light sources and acquire data with different phases between sources, and the acquired data would be used to generate an image of doubled resolution by the reconstruction algorithm. Most of current implementations require the use of grating to create interference pattern and phases between diffraction orders can be controlled by its mechanical movement. We propose an alternative implementation using optical fibres assembly and fibre phase shifters which provides more flexibility to interference pattern and mechanical control of phase can be replaced with an electrical one. In this thesis the experimental construction of interference between optical fibres would be demonstrated.