Ultrasensitive Kilo-Pixel Imaging Array of Photon Noise-Limited Kinetic Inductance Detectors Over an Octave of Bandwidth for THz Astronomy

J Bueno,V Murugesan,D J Thoen,J J A Baselmans,K Karatsu

doi:10.1007/s10909-018-1962-8

Abstract

We present the development of a background-limited kilo-pixel imaging array of ultrawide bandwidth kinetic inductance detectors (KIDs) suitable for space-based THz astronomy applications. The array consists of 989 KIDs, in which the radiation is coupled to each KID via a leaky lens antenna, covering the frequency range between 1.4 and 2.8 THz. The single pixel performance is fully characterised using a representative small array in terms of sensitivity, optical efficiency, beam pattern and frequency response, matching very well its expected performance. The kilo-pixel array is characterised electrically, finding a yield larger than 90% and an averaged noise-equivalent power lower than 3 times 10^{-19} W/Hz^{1/2}. The interaction between the kilo-pixel array and cosmic rays is studied, with an expected dead time lower than 0.6% when operated in an L2 or a similar far-Earth orbit.

Highlights

The generation of space-based imaging spectrometers for sub-millimetre wave astronomy requires broad band radiation coupling between 1 and 10 THz [1,2]
We identify large glitches that correspond to cosmic rays with large energy deposition on the chip; (iii) we calculate the rms of data from the previous step (i.e. 2nd derivative data from which large glitches are already removed) and identify points where the rms value is larger than 5 σ
A 989 pixels of leaky lens antenna-coupled kinetic inductance detectors (KIDs) imaging system providing an octave of bandwidth between 1.4 and 2.8 THz have been fabricated with a fabrication yield of 93%

Summary

Introduction

The generation of space-based imaging spectrometers for sub-millimetre (sub-mm) wave astronomy requires broad band radiation coupling between 1 and 10 THz [1,2]. J Low Temp Phys (2018) 193:96–102 tors (KIDs) are superconducting pair-breaking resonators [3] that are a very attractive choice for these applications since thousands of detectors can be read out with a single coaxial line [3,4], enabling simple and cost-effective systems. Since these spectrometers can only be used from space at these high frequencies, the requirements on the detector sensitivity [5] are extremely demanding, typically with an noiseequivalent power (NEP) of ∼ 3 × 10−19 W/Hz1/2 for a non-dispersive spectrometer. This device allows high coupling efficiency over an octave of bandwidth at frequencies higher than 1 THz

Design and Fabrication

Electrical Characterisation

Interaction Between the Detector Array and Cosmic Rays

Findings

Conclusions