A Hybrid THz Imaging System with a 100-Pixel CMOS Imager and a 3.25-3.50 THz Quantum Cascade Laser Frequency Comb

T. J. Smith, Anna Broome, Daniel Stanley, Jonas Westberg, Gerard Wysocki, Kaushik Sengupta

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations

Abstract

The terahertz frequency range beyond 3 THz has exciting potential to have a transformative impact in a wide range of applications,including chemical and biomedical sensing,spectroscopy,imaging,and short-distance wireless communication. While there have been significant advancements in silicon-based THz imagers in the frequency ranges below 1 THz,technological development beyond 3 THz has been impeded by the lack of solid-state sources in this frequency range. In addition,the design space beyond 3 THz opens up fundamentally new challenges across electronics and the electromagnetic interface. In this spectral range,the wavelength is small enough (λox ≈ 50 μm at 3 THz) that a vertical via from the top antenna layer to the detector is a distributed element (transmission line or radiator). In this letter,we follow a careful circuits-electromagnetics co-design approach toward a hybrid imaging system with a 100-pixel CMOS imager that interfaces with a THz quantum cascade laser frequency comb that spans 3.25-3.5 THz with mode spacing of 17 GHz. The array chip,while designed for an optimal operation across 2.7-2.9 THz,demonstrates an average noise equivalent power (NEP) (across pixels) of $1260\,{\text{pW}}/\sqrt {{\text{Hz}}}$ between 3.25-3.5 THz and a projected NEP of $284\,{\text{pW}}/\sqrt {{\text{Hz}}}$ across the design range of 2.7-2.9 THz. To the best of our knowledge,we demonstrate for the first time full THz imaging in a hybrid quantum cascade laser (QCL)-CMOS fashion. This approach allows future works to leverage both QCL and CMOS technologies to demonstrate new technological advances for systems in the 1-10 THz range.

Original language English (US) ESSCIRC 2019 - IEEE 45th European Solid State Circuits Conference Institute of Electrical and Electronics Engineers Inc. 151-154 4 9781728115504 https://doi.org/10.1109/ESSCIRC.2019.8902823 Published - Sep 2019 45th IEEE European Solid State Circuits Conference, ESSCIRC 2019 - Cracow, PolandDuration: Sep 23 2019 → Sep 26 2019

Publication series

Name ESSCIRC 2019 - IEEE 45th European Solid State Circuits Conference

Conference

Conference 45th IEEE European Solid State Circuits Conference, ESSCIRC 2019 Poland Cracow 9/23/19 → 9/26/19

All Science Journal Classification (ASJC) codes

• Instrumentation
• Electronic, Optical and Magnetic Materials
• Hardware and Architecture
• Electrical and Electronic Engineering

Keywords

• CMOS
• detector
• hybrid imaging
• imaging