The Future of Airborne Infrared/Submm Astronomy: Instrument Solutions

Tan

2-04

Boon-Kok Tan, Ghassan Yassin
Department of Astrophysics, University of Oxford

Novel Technologies for Large Pixel Count Heterodyne Array near THz Frequencies

A main challenge in the development of millimetre (mm) and sub-mm heterodyne receivers are the difficulties in deploying large array and achieving high sensitivity detection in the 1-2 THz range. In the past decades, we have been working on developing various generic technologies to find innovative solutions for both of these aspects. In this talk, we will summarise and present our latest research work on:  the first aspect is the development of high frequency Superconductor-Insulator-Superconductor (SIS) receivers from 600 GHz to 1 THz. This includes the use of planar superconducting circuit technology to replace bulky waveguides, incorporating on chip mixer capability, such as balanced or sideband separating schemes; and exploitation of high gap superconductors for mixer operation above 680 GHz, the critical frequency of the commonly used Niobium. The second aspect concerns with the novel technologies we have developed to simplify the RF operation of large pixel count heterodyne array. We will present the design of a novel easy-to-machine feed horn technology which enables deployment of large arrays with minimal cost. This technology has been demonstrated successfully and has since been used in various existing and up-coming telescope. We will also describe our attempts to develop a small pixel-count array near 220 GHz range, by combining both polarisation chains and local oscillator injection on a single chip. Finally, we will present our recent works on the superconducting parametric amplifier technology, which could potentially achieve quantum limited noise amplification with negligible heat dissipation, replacing the use of conventional semiconductor-based low noise amplifiers (LNAs) such as HEMTs. This could be important for many systems in particular those that require a large number of LNAs or applications that have limited cryogenic capacity such as airborne or space instruments.