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Plasmonic piezoelectric nanomechanical resonator for spectrally selective infrared sensing.

Hui Y, Gomez-Diaz JS, Qian Z, Alù A, Rinaldi M - Nat Commun (2016)

Bottom Line: We experimentally demonstrate that it is possible to achieve high thermomechanical coupling between electromagnetic and mechanical resonances in a single ultrathin piezoelectric nanoplate.The combination of nanoplasmonic and piezoelectric resonances allows the proposed device to selectively detect long-wavelength infrared radiation with unprecedented electromechanical performance and thermal capabilities.These attributes lead to the demonstration of a fast, high-resolution, uncooled infrared detector with ∼80% absorption for an optimized spectral bandwidth centered around 8.8 μm.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical &Computer Engineering at Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, USA.

ABSTRACT
Ultrathin plasmonic metasurfaces have proven their ability to control and manipulate light at unprecedented levels, leading to exciting optical functionalities and applications. Although to date metasurfaces have mainly been investigated from an electromagnetic perspective, their ultrathin nature may also provide novel and useful mechanical properties. Here we propose a thin piezoelectric plasmonic metasurface forming the resonant body of a nanomechanical resonator with simultaneously tailored optical and electromechanical properties. We experimentally demonstrate that it is possible to achieve high thermomechanical coupling between electromagnetic and mechanical resonances in a single ultrathin piezoelectric nanoplate. The combination of nanoplasmonic and piezoelectric resonances allows the proposed device to selectively detect long-wavelength infrared radiation with unprecedented electromechanical performance and thermal capabilities. These attributes lead to the demonstration of a fast, high-resolution, uncooled infrared detector with ∼80% absorption for an optimized spectral bandwidth centered around 8.8 μm.

No MeSH data available.


Device performance.(a) Measured admittance curve versus frequency and MBVD model fitting of the resonator for QIR=0. The extracted values of the MBVD parameters (see Methods) are as follows: Rs=80 Ω; Rm=880 Ω; Lm=1 mH; Cm=1 fF; R0=2 kΩ; C0=145 fF. (b) Measured response of the plasmonic piezoelectric resonator and a conventional AlN MEMS resonator to a modulated IR radiation emitted by a 1,500-K globar (2–16 μm broadband spectral range). (c) Measured frequency response of the detector. The 3dB cutoff frequency, f3 dB, was found to be 360 Hz, resulting in a time constant τ=1/(2πf3 dB) of 440 μs. (d) NEP for different values of thermal resistance (Rth). The solid lines indicate the calculated NEP values associated with each of the three fundamental noise contributions (as expressed in Supplementary Equations 5–6), assuming: resonator area=200 × 75 μm2, ɛ=1, T0=300 K, Pc=0 dBm, /TCF/=30 p.p.m. K−1, Q=2,000. The individual data points indicate the measured NEP values of four fabricated AlN resonant plasmonic IR detectors using four different anchor designs (hence four different Rth values) and a Si3N4 nanobeam (spectrally selective, static measurement using off-chip optical readout)34. IR, infrared.
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f3: Device performance.(a) Measured admittance curve versus frequency and MBVD model fitting of the resonator for QIR=0. The extracted values of the MBVD parameters (see Methods) are as follows: Rs=80 Ω; Rm=880 Ω; Lm=1 mH; Cm=1 fF; R0=2 kΩ; C0=145 fF. (b) Measured response of the plasmonic piezoelectric resonator and a conventional AlN MEMS resonator to a modulated IR radiation emitted by a 1,500-K globar (2–16 μm broadband spectral range). (c) Measured frequency response of the detector. The 3dB cutoff frequency, f3 dB, was found to be 360 Hz, resulting in a time constant τ=1/(2πf3 dB) of 440 μs. (d) NEP for different values of thermal resistance (Rth). The solid lines indicate the calculated NEP values associated with each of the three fundamental noise contributions (as expressed in Supplementary Equations 5–6), assuming: resonator area=200 × 75 μm2, ɛ=1, T0=300 K, Pc=0 dBm, /TCF/=30 p.p.m. K−1, Q=2,000. The individual data points indicate the measured NEP values of four fabricated AlN resonant plasmonic IR detectors using four different anchor designs (hence four different Rth values) and a Si3N4 nanobeam (spectrally selective, static measurement using off-chip optical readout)34. IR, infrared.

Mentions: The electromechanical performance of the resonator was characterized by measuring its admittance versus frequency (Fig. 3a). A high Q=1,116 and electromechanical coupling coefficient kt2=0.86% were extracted by equivalent model fitting (Fig. 3a; Methods), demonstrating the unique advantages of the proposed design in terms of high electromechanical transduction efficiency and low loss. The thermal properties (thermal resistance, temperature distribution and TCF) of the infrared detector were characterized by both finite element analysis and experimental verification (Supplementary Figs 5–8; Supplementary Table 1; Supplementary Note 4). The response of the fabricated infrared detector in the LWIR band was characterized using a 1,500-K globar (2–16-μm emission) as an infrared source. For the sake of comparison, the incoming infrared radiation was also detected using a conventional AlN MEMS resonator with same frequency sensitivity to absorbed heat but without plasmonic pattern (hence non-enhanced infrared absorptance). Thanks to its properly engineered optical properties, the piezoelectric plasmonic resonator showed fourfold enhanced responsivity (Fig. 3b), despite its absorption band (full width at half maximum of 1.5 μm) being much narrower than the emission band of the source. With a narrowband source at the frequency of interest, the responsivity would be much larger. The smallest impinging optical power that can be detected was experimentally estimated by measuring the device responsivity, Rs, and noise spectral density (Supplementary Note 5), demonstrating a low noise equivalent power (NEP) ∼2.1 nW Hz−1/2 at the designed spectral wavelength (for which infrared absorptance ∼80%). The NEP is arguably considered the most important performance metric for an infrared detector (Supplementary Note 5) and the value measured for the realized proof-of-concept detector proposed here is already comparable to the best commercially available uncooled broadband thermal detectors, while providing unique spectral selectivity in the LWIR band. The response time of the detector was also evaluated by measuring the attenuation of the device response when exposed to infrared radiation modulated at increasingly faster rates (Fig. 3c; Methods), showing a low-thermal time constant, τ ∼440 μs.


Plasmonic piezoelectric nanomechanical resonator for spectrally selective infrared sensing.

Hui Y, Gomez-Diaz JS, Qian Z, Alù A, Rinaldi M - Nat Commun (2016)

Device performance.(a) Measured admittance curve versus frequency and MBVD model fitting of the resonator for QIR=0. The extracted values of the MBVD parameters (see Methods) are as follows: Rs=80 Ω; Rm=880 Ω; Lm=1 mH; Cm=1 fF; R0=2 kΩ; C0=145 fF. (b) Measured response of the plasmonic piezoelectric resonator and a conventional AlN MEMS resonator to a modulated IR radiation emitted by a 1,500-K globar (2–16 μm broadband spectral range). (c) Measured frequency response of the detector. The 3dB cutoff frequency, f3 dB, was found to be 360 Hz, resulting in a time constant τ=1/(2πf3 dB) of 440 μs. (d) NEP for different values of thermal resistance (Rth). The solid lines indicate the calculated NEP values associated with each of the three fundamental noise contributions (as expressed in Supplementary Equations 5–6), assuming: resonator area=200 × 75 μm2, ɛ=1, T0=300 K, Pc=0 dBm, /TCF/=30 p.p.m. K−1, Q=2,000. The individual data points indicate the measured NEP values of four fabricated AlN resonant plasmonic IR detectors using four different anchor designs (hence four different Rth values) and a Si3N4 nanobeam (spectrally selective, static measurement using off-chip optical readout)34. IR, infrared.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4835539&req=5

f3: Device performance.(a) Measured admittance curve versus frequency and MBVD model fitting of the resonator for QIR=0. The extracted values of the MBVD parameters (see Methods) are as follows: Rs=80 Ω; Rm=880 Ω; Lm=1 mH; Cm=1 fF; R0=2 kΩ; C0=145 fF. (b) Measured response of the plasmonic piezoelectric resonator and a conventional AlN MEMS resonator to a modulated IR radiation emitted by a 1,500-K globar (2–16 μm broadband spectral range). (c) Measured frequency response of the detector. The 3dB cutoff frequency, f3 dB, was found to be 360 Hz, resulting in a time constant τ=1/(2πf3 dB) of 440 μs. (d) NEP for different values of thermal resistance (Rth). The solid lines indicate the calculated NEP values associated with each of the three fundamental noise contributions (as expressed in Supplementary Equations 5–6), assuming: resonator area=200 × 75 μm2, ɛ=1, T0=300 K, Pc=0 dBm, /TCF/=30 p.p.m. K−1, Q=2,000. The individual data points indicate the measured NEP values of four fabricated AlN resonant plasmonic IR detectors using four different anchor designs (hence four different Rth values) and a Si3N4 nanobeam (spectrally selective, static measurement using off-chip optical readout)34. IR, infrared.
Mentions: The electromechanical performance of the resonator was characterized by measuring its admittance versus frequency (Fig. 3a). A high Q=1,116 and electromechanical coupling coefficient kt2=0.86% were extracted by equivalent model fitting (Fig. 3a; Methods), demonstrating the unique advantages of the proposed design in terms of high electromechanical transduction efficiency and low loss. The thermal properties (thermal resistance, temperature distribution and TCF) of the infrared detector were characterized by both finite element analysis and experimental verification (Supplementary Figs 5–8; Supplementary Table 1; Supplementary Note 4). The response of the fabricated infrared detector in the LWIR band was characterized using a 1,500-K globar (2–16-μm emission) as an infrared source. For the sake of comparison, the incoming infrared radiation was also detected using a conventional AlN MEMS resonator with same frequency sensitivity to absorbed heat but without plasmonic pattern (hence non-enhanced infrared absorptance). Thanks to its properly engineered optical properties, the piezoelectric plasmonic resonator showed fourfold enhanced responsivity (Fig. 3b), despite its absorption band (full width at half maximum of 1.5 μm) being much narrower than the emission band of the source. With a narrowband source at the frequency of interest, the responsivity would be much larger. The smallest impinging optical power that can be detected was experimentally estimated by measuring the device responsivity, Rs, and noise spectral density (Supplementary Note 5), demonstrating a low noise equivalent power (NEP) ∼2.1 nW Hz−1/2 at the designed spectral wavelength (for which infrared absorptance ∼80%). The NEP is arguably considered the most important performance metric for an infrared detector (Supplementary Note 5) and the value measured for the realized proof-of-concept detector proposed here is already comparable to the best commercially available uncooled broadband thermal detectors, while providing unique spectral selectivity in the LWIR band. The response time of the detector was also evaluated by measuring the attenuation of the device response when exposed to infrared radiation modulated at increasingly faster rates (Fig. 3c; Methods), showing a low-thermal time constant, τ ∼440 μs.

Bottom Line: We experimentally demonstrate that it is possible to achieve high thermomechanical coupling between electromagnetic and mechanical resonances in a single ultrathin piezoelectric nanoplate.The combination of nanoplasmonic and piezoelectric resonances allows the proposed device to selectively detect long-wavelength infrared radiation with unprecedented electromechanical performance and thermal capabilities.These attributes lead to the demonstration of a fast, high-resolution, uncooled infrared detector with ∼80% absorption for an optimized spectral bandwidth centered around 8.8 μm.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical &Computer Engineering at Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, USA.

ABSTRACT
Ultrathin plasmonic metasurfaces have proven their ability to control and manipulate light at unprecedented levels, leading to exciting optical functionalities and applications. Although to date metasurfaces have mainly been investigated from an electromagnetic perspective, their ultrathin nature may also provide novel and useful mechanical properties. Here we propose a thin piezoelectric plasmonic metasurface forming the resonant body of a nanomechanical resonator with simultaneously tailored optical and electromechanical properties. We experimentally demonstrate that it is possible to achieve high thermomechanical coupling between electromagnetic and mechanical resonances in a single ultrathin piezoelectric nanoplate. The combination of nanoplasmonic and piezoelectric resonances allows the proposed device to selectively detect long-wavelength infrared radiation with unprecedented electromechanical performance and thermal capabilities. These attributes lead to the demonstration of a fast, high-resolution, uncooled infrared detector with ∼80% absorption for an optimized spectral bandwidth centered around 8.8 μm.

No MeSH data available.