Photonic Spectroscopy in Astronomy

Abstract

This thesis investigates photonic spectroscopy and its use in astronomy.
In chapter two the theory associated with both astronomical spectroscopy and photonic spectroscopy is shown. The convergence of the two in the field of astrophotonics is discussed along with existing work in the field.
In chapter three models of the Integrated Photonic Spectrograph are created and compared like-for-like with existing instruments. The results suggest that the Integrated Photonic Spectrograph will be similar to existing instruments in terms of size and will require more detector pixels for a full instrument.
In chapter four the modelling is extended, examining the areas where pho- tonic spectroscopy could show advatanges over conventional instrumentation. This is done by varying spectral resolution, telescope diameter, seeing and num- ber of objects sampled. The results show that the Integrated Photonic Spec- trograph will perform best when the telescope is close to the diffraction-limit, both in terms of size and number of detector pixels required. Science cases are presented for these areas.
In chapter five different concepts for a redesigned Integrated Photonic Spec- trograph are presented and the advantages and disadvatanges of the variations are commented upon. The two that are chosen for development require the telescope Point Spread Function to be reformatted to a long slit.
This device, which we have named the photonic-dicer is presented in chapter six. Its design, manufacture and testing is discussed both in the laboratory and on sky in conjunction with the CANARY adaptive optics system.
Finally chapter seven presents our concluding remarks and discussions for future work.