Future electronics: Photonics and plasmonics at the nanoscale

Robert Magnusson Texas Instruments Distinguished University Chair in Nanoelectronics Professor of Electrical Engineering Department of Electrical Engineering University of Texas-Arlington Arlington, Texas 76019 magnusson@uta.edu http://leakymoderesonance.com/

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Applied Power Electronics Conference Fort Worth, Texas March 16 – 20, 2014

Scope

Plasmonics: Surface plasmons are coherent electron oscillations at the interface between two materials where the real part of the dielectric function changes sign across the interface.

Nanoplasmonics: Plasmonics in nanoscale systems. Photonics: Technology concerned with the properties and transmission of

photons, for example in fiber optics, waveguides, and lasers. Nanophotonics the study of the behavior of light on a nanometer scale.

Engineering the interaction of light with particles or substances at deeply subwavelength scales.

Silicon photonics: CMOS! Focus: Nanophotonic and nanoplasmonic periodic devices.

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Surface plasmons on dielectric-metal boundaries

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Nanoplasmonics

Metal coupler example

Jesse Lu, Csaba Petre, Eli Yablonovitch, and Josh Conway, “Numerical optimization of a grating coupler for the efficient excitation of surface plasmons at an Ag–SiO2 interface,” J. Opt. Soc. Am. B/Vol. 24, No. 9/September 2007

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Undergrad plasmonics: SPR sensor experiment

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SP-highlights Surface plasmon: EM field charge-density oscillation at the interface

between a conductor and a dielectric SP: AC current at optical frequency Metallic structures: Concentrate/focus/guide light via SPs SP localization: Better than with dielectric optical means Efficient coupling/manipulation: Under intensive research Plasmonics: An electronics/photonics interface

Our interest:

– Interaction/generation of plasmonic states employing leaky-mode resonance effects – Fundamental plasmonic research in periodic nanostructures – Theory and experiment in all cases

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Collective excitation of the free electrons in a metal Can be excited by light: photon-electron coupling (polariton)=SPP Thin metal films or metal nanoparticles Bound to the interface (exponentially decaying along the normal) Longitudinal surface wave in metal films Can be highly confined in nanostructures (localized plasmon) Propagates along the interface: few µm to several mm (long range plasmon)

Surface plasmons-key properties

Note: SP is a TM wave!

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Model Device: Canonical periodic element Tranmission and modal properties

Fixed Parameters εmetal = -5, F = 0.05

incE

incH

Λ

FΛ

metalε

d

air air

Yiwu Ding, Jaewoong Yoon, Muhammad H. Javed, Seok Ho Song, and Robert Magnusson, “Mapping surface-plasmon polaritons and cavity modes in extraordinary optical transmission,” IEEE Photonics Journal, vol. 3, no. 3, pp. 364–374, June 2011. 8

Device possesses mixed cavity-modal (CM) and surface-plasmon states (SPP) => EOT=extraordinary transmission

Parametric Map of transmission function EOT

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.00.0

0.2

0.4

0.6

0.8

1.0

Λ/λ

d/λ

TM0

mixed SPP/CM region d/Λ=0.086 0.2 0.37 0.46 0.72

cavity mode (CM) region

TM1 TM2

TM3 TM4 TM5 TM6

TM7

even mode odd mode higher order SPP

pure SPP region

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0.2 0.3 0.4 0.5 0.6 0.7 0.80.5

0.6

0.7

0.8

0.9

1.0

Λ/λ

d/λ

Mixed SPP-CM Region

magnetic field patterns on TM2 curve

• Gradual increase of surface field enhancement associated with SPP excitation • Abrupt change in Fabry-Perot condition • Missing resonance peaks

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Leaky modes and plasmons:

Hybrid resonance elements

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0.5 0.6 0.7 0.8 0.9 1.00.0

0.2

0.4

0.6

0.8

1.0

d=0 d=100nm d=900nm

R 0

wavelength (µm)

Au

dielectric (n = 1.6)

I R0

F=0.4 (fixed)

TM(a) (b)

(c)

air

d = 100 nm, λ = 710.5 nm

(d)

d = 900 nm, λ = 618.5 nm0

5

10

15

20

0

5

10

15

d

FΛ Λ

Robert Magnusson, Halldor Svavarsson, Jae Woong Yoon, Mehrdad Shokooh-Saremi, and Seok-Ho Song, “Experimental observation of leaky modes and plasmons in a hybrid resonance element,” Applied Physics Letters, vol. 100, no. 9, pp. 091106-1–091106-3, February 29, 2012.

Measured spectra-computed fields

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500 nmsilicon

AuPR

0.0

0.2

0.4

0.6

0.8

1.0

R 0

TM

0.60 0.65 0.70 0.75 0.80 0.85 0.900.00.2

0.40.60.81.0

wavelength (µm)

TE

SPP(799 nm)

TM1(669 nm)

calculated

measured

calculated

measuredTE0

(725 nm)

0

10

5

0

16

8

0

20

10

TM1

air PR

AuSi

(a)

(b)

(c) TE0

SPP

Appl. Phys. Lett. 2012 Parameters: Λ = 653 nm, dPR = 560 nm, dAu = 80 nm, n = 1.6, and F = 0.35.

Silicon photonics: Intel vision

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Motivation for silicon photonics Limits of microelectronics evolution Optical communication evolution Interconnection bottlenecks Compact, low loss, EMI properties SiPhot=new technology platform Low cost High performance

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15 Reference: Silicon Photonics–PhD course prepared within FP7-224312 Helios project

Huge opportunities for innovation!

16 Reference: Silicon Photonics–PhD course prepared within FP7-224312 Helios project

Basic resonance interactions Excitation of a leaky eigenmode in 1D periodic layers

Higher-order diffraction regime Zero-order diffraction regime

Properties of 2D nanopatterns similar in principle

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Experimental spectra

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1460 1480 1500 1520 1540 1560 15800.0

0.2

0.4

0.6

0.8

1.0

Theory Experiment

R

efle

ctan

ce

Wavelength (nm)

1450 1500 1550 1600 1650 1700 17500.0

0.2

0.4

0.6

0.8

1.0

TE TM

Tran

smitt

ance

Wavelength (nm)

0.78 0.79 0.8 0.81 0.82 0.83 0.84 0.85 0.860

0.2

0.4

0.6

0.8

1

Wavelength(µm)

Tra

nsm

ittan

ce

SimulationExperiment

1.4 1.45 1.5 1.55 1.6 1.65

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

λ (µm)

Tran

smitt

ance

SimulatedMeasured

• Interesting physics/properties

• Complex, interacting resonant leaky modes

• 1D or 2D periodic layers

• Applicable to dielectrics, semiconductors, metals

• Applicable to photonic, THz, microwave spectral regions

• Remaining challenges in analysis

• Remaining challenges in fabrication

• Many potential application fields

• Applications emerging ~Biosensors

• Favorable area for R&D&A

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Guided-mode resonance nanophotonics: Innovation/applications platform

Unknown unknowns

Known knowns

R. Magnusson et al., “Extraordinary capabilities of optical devices incorporating guided-mode resonance gratings,” Optoelectronic Devices and Materials (OPTO), Photonic Integration: Integrated Optics: Devices, Materials, and Technologies XVIII, SPIE Photonics West 2014, San Francisco, California, February 1–6, 2014.

Guided-mode resonance technology: Application summary

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Frequency selective elements - Narrowband bandstop/bandpass filters (∆λ~sub nm) - Wavelength division multiplexing (WDM) - Ultra high-Q thin-film resonators - Laser resonator frequency selective mirrors Biochemical sensors - Spectroscopic biosensors - Chemical and environmental sensors - Multiparametric biosensors (biolayer thickness, refractive index, and background in a single

measurement) Wideband lossless mirrors - Wideband bandstop/bandpass filters (∆λ~100’s nm) - Mirrors for vertical-cavity lasers - Omnidirectional reflectors Polarization control elements - Polarization independent reflection/transmission elements for both 1D and 2D periodicity - Narrow or wideband polarizers - Non-Brewster polarizing laser mirrors - Polarization control including wave plates

Guided-mode resonance technology: Application summary

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Tunable elements - Tunable filters, EO modulators, and switches - Liquid-crystal integrated tunable devices - Laser cavity tuning elements - MEMS-tunable display pixels and filters - Thermally tuned silicon filters Security devices - Resonant Raman templates - Compact non-dispersive spectroscopy Thin-film light absorbers - Absorbance-enhanced solar cells - Omnidirectional, wideband, polarization-independent absorbers - GMR coherent perfect absorbers Photonic metasurfaces - Wavefront-shaping elements including focusing reflectors Dispersive elements - Slow-light/dispersion elements Hybrid resonant elements - Leaky-mode nanoplasmonics - Hybrid plasmonic/modal resonance sensors - Rayleigh reflectors with sharp angular cutoff - Rayleigh-anomaly based GMR transmission filters

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Wideband resonant reflectors

T0

SiO2

air

Ge

FΛ Λ

dg dh

x

y z

R0

2.0 2.2 2.4 2.6 2.8 3.0 3.20.0

0.2

0.4

0.6

0.8

1.0

R0

zero

-ord

er e

fficie

ncy

wavelength (µm)

T0

Model and reflectance/transmittance spectra of a GMR mirror applying a partially etched Ge layer. Input light is in a TM polarization state.

BW~900 nm

R. Magnusson et al., “Extraordinary capabilities of optical devices incorporating guided-mode resonance gratings,” Optoelectronic Devices and Materials (OPTO), Photonic Integration: Integrated Optics: Devices, Materials, and Technologies XVIII, SPIE Photonics West 2014, San Francisco, California, February 1–6, 2014.

Color filter array: Design

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Period-tuned resonance wavelengths enabling RGB color filters.

Parameters: n = 2.02, F = 0.5, dg = 55 nm, and dh = 110 nm.

Designed and optimized with RCWA

Mohammad J. Uddin and Robert Magnusson, “Highly efficient color filter array using resonant Si3N4 gratings,” Optics Express, vol. 21, no. 10, pp. 12495–12506, May 20, 2013.

Results: Spectral measurements

Device Parameters: dg = ≈ 60 nm, dh ≈ 105 nm, F = 0.46.

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High experimental efficiency (> 95%) with low crosstalk

Mohammad J. Uddin and Robert Magnusson, “Highly efficient color filter array using resonant Si3N4 gratings,” Optics Express, vol. 21, no. 10, pp. 12495–12506, May 20, 2013.

Label-free Microarrays Based on Guided-mode Resonance Technology

ResonantSensors.com 817-735-0634 info@ResonantSensors.com

Products Features

Fully automated benchtop reader Optical resonance with real-time data

96-well and 384-well disposable label-free microarray plates

Cell-based and biochemical assays

Pre-sensitized kits: standard and custom

Dual-resonance detection enables two data points for every measurement

Comprehensive assay support for transition to label-free

Multiplexing capability

Conclusions • Nanoplasmonics

– Light on metals-compact devices – Loss/gain compromise – Rapid R&D

• Silicon photonics – CMOS infrastructure – Integrated electronics/photonics chips – Commercial now – Under intense development

• Nanophotonics – Device development opportunities – Opportunities in entrepreneurship/innovation

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magnusson@uta.edu