Adaptive optics for microscopy and photonic engineering

I report on the development and application of adaptive optics to three-dimensional (3D) microscopy and optical engineering. Numerous optical techniques have been developed using the properties of light to examine, modify or control objects with 3D precision on the nanometre to micrometre scale. These techniques rely on the use of high quality optics with the goal of obtaining diffraction-limited operation, working at the physical limits imposed by the wavelength of the light. Yet in many cases this goal is not achieved as aberrations, distortions in the optical wavefront often introduced by the object itself, blur the focus and reduce the resolution of the system. Since these aberrations vary they require an adaptive method of correction. These adaptive optics methods were originally developed for astronomical and military telescopes. Recent technological developments, such as compact deformable mirrors or inexpensive display-type liquid crystal devices, mean that this aberration correction technology is now being developed for smaller scale applications. Using such devices, we have developed enabling techniques that are applicable across fields ranging from biological imaging to the fabrication of photonic devices. This research encompasses the theoretical basis of aberration measurement and correction, the practical implementation of adaptive optics systems and the development of applications. I will describe the background to the 3D resolved optical methods, adaptive optics and the two main application areas, namely high-resolution microscopy and optical fabrication systems. These seemingly dissimilar application areas are actually closely linked, as they employ almost identical optical systems based around laser scanning and high numerical aperture objective lenses. The wide applicability of these enabling technologies means that there is significant scope for expansion of this research into new areas.