Optomechanical metamaterial nanobolometer

Dimitrios Papas,Nikolay I Zheludev,Jun-Yu Ou,Eric Plum

doi:10.1063/5.0073583

Dimitrios Papas, Nikolay I Zheludev + Show 2 more

Open Access

https://doi.org/10.1063/5.0073583

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Abstract

Bolometers are detectors of electromagnetic radiation that usually convert the radiation-induced change in temperature of the detector into electric signals. Temperature-dependent electrical resistance in semiconductors and superconductors, the thermoelectric effect in thermocouples, and the pyroelectric effect of transient electric polarization of certain materials when they are heated or cooled are among the underlying physical phenomena used in bolometers. Here, we report that the dependence of the fundamental frequency of a nanowire string detected via scattering of light on the string can be used in a bolometer. Arrays of such nanowires can serve as detectors with high spatial and temporal resolution. We demonstrate a bolometer with 400 nm spatial resolution, 2–3 µs thermal response time, and optical power detection noise floor at 3–5 nW/Hz1/2 at room temperature.

Highlights

Bolometers detect radiation by measuring temperature increases due to radiation absorption, a principle that is applicable across the electromagnetic spectrum and that permits uncooled detection even of infrared and lower energy radiation
They consist of an absorber and a temperature sensor that are thermally insulated from their surroundings
We combine nanomechanics and metamaterials to demonstrate an optomechanical metamaterial nanobolometer, where radiation absorption is controlled by the metamaterial design and read optically through light modulation caused by mechanical motion

Summary

INTRODUCTION

Bolometers detect radiation by measuring temperature increases due to radiation absorption, a principle that is applicable across the electromagnetic spectrum and that permits uncooled detection even of infrared and lower energy radiation. We combine nanomechanics and metamaterials to demonstrate an optomechanical metamaterial nanobolometer, where radiation absorption is controlled by the metamaterial design and read optically through light modulation caused by mechanical motion. It exploits the fundamental Brownian motion of nanomechanical oscillators as a signature of temperature. Our proofof-principle experiments demonstrate non-contact optical readout with 400 nm spatial resolution, 2–3 μs thermal time constants, and nanowatt detectable power based on 2–3%/μW resonance frequency shift per unit of incident optical power (responsivity) with 3–5 nW/Hz1/2 noise equivalent power in an optomechanical metamaterial nanobolometer of only 100 nm thickness. Advantages of our optically read nanobolometer over prior microbolometer arrays include smaller sensing elements with more than an order of magnitude higher spatial resolution and two orders of magnitude shorter thermal time constant

CONCEPT AND THEORY

METAMATERIAL NANOWIRE PAIR NANOBOLOMETER

MECHANICAL METAMATERIAL NANOBOLOMETER

Findings

DISCUSSION

CONCLUSIONS