Superconducting Integrated Terahertz Spectrometers

Abstract

A superconducting integrated receiver (SIR) comprises all of the elements needed for heterodyne detection on a single chip. Light weight and low power consumption combined with nearly quantum-limited sensitivity and a wide tuning range of the superconducting local oscillator make the SIR a perfect candidate for many practical applications. For the first time, we demonstrated the capabilities of the SIR technology for remote operation under harsh environmental conditions and for heterodyne spectroscopy at atmospheric limb sounding on board a high-altitude balloon. Recently, the SIR was successfully implemented for the first spectral measurements of THz radiation emitted from intrinsic Josephson junction stacks (BSCCO mesa) at frequencies up to 750 GHz; linewidth below 10 MHz has been recorded in the high bias regime. The phase-locked SIR has been used for the locking of the BSCCO oscillator under the test. To extend the operation range of the SIR well above 1 THz, a new technique for fabrication of high-quality SIS tunnel junctions with gap voltage Vg up to 5.3 mV has been developed. Integration of a superconducting high-harmonic phase detector with a cryogenic oscillator opens a possibility for efficient phase locking of the sources with free-running linewidth up to 30 MHz that is important both for BSCCO mesa and NbN/MgO/NbN oscillators.

Josephson flux-flow oscillator: The microscopic tunneling approach

“…Refs. [65,69,[104][105][106]). The layouts of the FFO samples were optimized for coupling to load by using the sharpened edge geometries: the width 16 μm in the central region was degraded linearly to about 1 μm on a distance 40 μm (30 μm for the 60 μm junction) from either end.…”

“…To accommodate multiple fluxons and achieve a flux-flow regime, the length of the Josephson junction used as a FFO exceeds the Josephson penetration length by a large factor. The potential of FFO for practical applications has been justified by development of a superconducting integrated receiver (SIR) [65,66] which was successfully used in remote heterodyne spectroscopy of the Earth atmosphere on board of a high-altitude balloon [67,68], as well as first spectral measurements of THz radiation emitted from intrinsic Josephson junction stacks (BSCCO mesa) at frequencies up to 750 GHz [69,70].…”

Performance Assessment of Balloon-Borne Trace Gas Sounding with the Terahertz Channel of TELIS

“…Detailed information about the sensor design and the measurement capabilities of the TELIS 480-650 GHz channel can be found in [31,[34][35][36][37]. A feasibility study of isotopic water retrievals using synthetic TELIS data and the first results of hydrogen chloride (HCl) and chlorine monoxide (ClO) using real data during the 2010 campaign were presented in [38,39], respectively.…”

Optical Transistor for Amplification of Radiation in a Broadband Terahertz Domain

“…The difference is that here the amplification can occur in a broad frequency range simultaneously, while in lasers it is pinned to a specific resonant frequency. Such amplification of the broadband spectrum, e.g., for chaotic or noise radiation, opens exciting opportunities of new types of molecular and biological noise spectroscopy, where the response of the system can be measured in a broad frequency range opening new opportunities in molecular and biological noise spectroscopy [78].…”