A deeper focus on the primordial universe: Development of a metamaterial-based lenslet coupled with kinetic inductance detectors for Cosmology.

点击翻译按钮获取中文摘要

Measurements of the polarisation states of the Cosmic Microwave Background (CMB) radiation is currently one of the hottest topics in Cosmology. In particular, the detection of the associated primordial B-modes is the present challenge in this field. The Astronomy Instrumentation Group, within the School of Physics and Astronomy, is involved in many projects world-wide targeting the detection of the B-modes. The B-mode signals are extremely weak and require instrumentation with extraordinary sensitivity and exquisite control of the optical systematic effects. High sensitivity can be achieved by using thousands of detectors coupled to very compact arrays of pixels/antennas. Current solutions based on 'lenslet' arrays rely on small and very-curved lenses which are not easy to manufacture and require specifically designed anti-reflection coatings to work efficiently. In this project we propose to develop high performance and compact lenslet arrays based on metamaterials. The Astronomy Instrumentation Group is world-leading in the design and production quasi-optical devices based the 'mesh-filters' technology. We have recently developed flat 'mesh-lenses' able to accurately mimic the behaviour of thicker standard lenses. These lenses can be 'miniaturised' and coupled to array of detectors. A mesh-lens array can be a simple flat device which includes all the small lenses.The modelling and the design of these arrays will be carried out by using electromagnetic finite element analysis (Ansys HFSS). The devices will be manufactured and tested within the group cleanrooms and laboratories. The electromagnetic characterisation will be performed with Fourier Transform Spectrometers (FTSs) and Vector Network Analysers (VNAs).The work will be carried out also in collaboration with the Colorado University and the National Institute of Standard and Technology (NIST).The PhD research project will consist of:- Metamaterials electromagnetic modelling using finite-element analysis software (HFSS)- Design and optimisation of a novel lenslet array based on metamaterials- Assistance in the manufacture of the device within the group facilities- Device testing with Fourier Transform Spectrometers and Vector Network Analysers- Analysis and interpretation of the data