Uncooled Thermal Infrared Detection Near the Fundamental Limit Using a Nanomechanical Resonator with a Broadband Absorber

Fuente: arXiv
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Main Authors: Martini, Paolo, Emminger, Stefan, Kanellopulos, Kostas, Luhmann, Niklas, Piller, Markus, West, Robert Greyson, Schmid, Silvan
Format: Preprint
Published: 2025
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author Martini, Paolo
Emminger, Stefan
Kanellopulos, Kostas
Luhmann, Niklas
Piller, Markus
West, Robert Greyson
Schmid, Silvan
author_facet Martini, Paolo
Emminger, Stefan
Kanellopulos, Kostas
Luhmann, Niklas
Piller, Markus
West, Robert Greyson
Schmid, Silvan
contents This paper introduces a thermal infrared detector utilizing a nano-optomechanical silicon nitride (SiN) resonator, equipped with a free-space impedance-matched (FSIM) absorber composed of a platinum (Pt) thin film, offering a broadband spectral absorptance on average of 47%. To reduce photothermal back-action caused by intensity fluctuations of the readout laser, the FSIM absorber incorporates a circular clearance for the laser. The study provides a comprehensive characterization of the thermal time constant, power responsivity, and frequency stability of the resonators, with experimental results compared to analytical models and finite element method (FEM) simulations. The fastest thermal response is observed for the smallest 1 mm resonators, with a thermal time constant tau_th = 14 ms. The noise equivalent power (NEP) of the resonators is assessed, showing that the smallest 1 mm resonators exhibit the best sensitivity, with NEP = 27 pW/sqrt(Hz) and a respective specific detectivity of D* = 3.8e9 cm sqrt(Hz)/W. This is less than three times below the theoretical maximum for an ideal IR detector with 50% absorptance. This places our resonators among the most sensitive room-temperature IR detectors reported to date offering an extended spectral range from the near-IR to far-IR. This work underscores the potential of nano-optomechanical resonators for high-performance IR sensing applications.
format Preprint
id arxiv_https___arxiv_org_abs_2501_03161
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Uncooled Thermal Infrared Detection Near the Fundamental Limit Using a Nanomechanical Resonator with a Broadband Absorber
Martini, Paolo
Emminger, Stefan
Kanellopulos, Kostas
Luhmann, Niklas
Piller, Markus
West, Robert Greyson
Schmid, Silvan
Instrumentation and Detectors
This paper introduces a thermal infrared detector utilizing a nano-optomechanical silicon nitride (SiN) resonator, equipped with a free-space impedance-matched (FSIM) absorber composed of a platinum (Pt) thin film, offering a broadband spectral absorptance on average of 47%. To reduce photothermal back-action caused by intensity fluctuations of the readout laser, the FSIM absorber incorporates a circular clearance for the laser. The study provides a comprehensive characterization of the thermal time constant, power responsivity, and frequency stability of the resonators, with experimental results compared to analytical models and finite element method (FEM) simulations. The fastest thermal response is observed for the smallest 1 mm resonators, with a thermal time constant tau_th = 14 ms. The noise equivalent power (NEP) of the resonators is assessed, showing that the smallest 1 mm resonators exhibit the best sensitivity, with NEP = 27 pW/sqrt(Hz) and a respective specific detectivity of D* = 3.8e9 cm sqrt(Hz)/W. This is less than three times below the theoretical maximum for an ideal IR detector with 50% absorptance. This places our resonators among the most sensitive room-temperature IR detectors reported to date offering an extended spectral range from the near-IR to far-IR. This work underscores the potential of nano-optomechanical resonators for high-performance IR sensing applications.
title Uncooled Thermal Infrared Detection Near the Fundamental Limit Using a Nanomechanical Resonator with a Broadband Absorber
topic Instrumentation and Detectors
url https://arxiv.org/abs/2501.03161