On-chip optical nanoscopy: towards high throughput and multi-modality

Abstract

Super-resolution microscopy techniques improve the resolution of the optical microscope beyond the diffraction limit of light. A range of different techniques demands different optical configurations and clever illuminating strategies to enhance the resolution. This has led to the development of advanced instrumentation, where the super-resolution mechanisms are adding both cost and bulk to the microscope. Furthermore, super-resolution microscopes are bound by high numerical aperture optics, which produce convincing images, but lack throughput. A common feature of most optical microscopes is the sample glass/coverglass arrangement used to mount samples before and during imaging. These have traditionally been neutral devices where the properties of the glass itself have mostly remained unused. In this thesis, a new direction in super-resolution imaging is introduced, where the sample glass/coverglass is replaced with a photonic integrated circuit chip. The chip supports the sample in the same way as the glass/coverglass, and by using optical waveguides at the chip surface, the chip illuminates the specimen via evanescent fields. By using high refractive index waveguides together with different geometries, the chip can produce the necessary illumination for a range of different super-resolution microscopy techniques. Furthermore, by exploiting the waveguide properties, several of the imaging methods are improved over their conventional implementations. This comes as a consequence of separating the excitation and collection light paths for super-resolution imaging. In this work, chip-based single-molecule localization microscopy is demonstrated with a 100 times increase in the field of view over conventional methods, and chip-based structured illumination microscopy is shown with a resolution beyond that of the objective-based implementation.