Intensity (uW)

Surface-plasmon waveguides

(Fourth Lecture) Techno Forum on Micro-optics and Nano-optics Technologies

p g

for biosensor applications

송 석 호 한양대학교 물리학과 http://optics anyang ac kr/~shsong 송 석 호, 한양대학교 물리학과, http://optics.anyang.ac.kr/~shsong

metal strip metal slab

Y-branch S-band

metal slab

Metal SPP waveguide

300 350

Output signal

50 100 150 200 250

Intensity (uW)

1. How do we define the dispersion relations of SPPs excited on thin metal films and stripes?

1.330 1.331 1.332 1.333 1.334 1.335 1.336 0

Refractive index of water

Reference arm Sensing arm

p p

2. What are the long-range SPPs and short-range SPPs?

2. How can we implement LRSPP waveguide devices?

4. What are the merits of the LRSPP waveguide-type sensors?

Key notes

Biosensors

시료 전달 채널 바이오시료

박테리아 바이러스

target

바이오바이오//환경환경//화학화학 센서센서 SchematicSchematic

시료 전달 채널 바이러스

공해물질 화학물질

…

^Detector

Transducer

표적시료 신호/data

처리 Receptor

전기식 광학식 표면음파식 열방식

표적물질의 함량정보

L S f Pl id

Long-range Surface Plasmon waveguide Good probing evanescent tail

Integrated Optics in MZI configuration

High sensitivityg y

Very compact & sensitive sensor!

휴대폰용 Biosensors

당뇨폰

음주측정폰

입냄새폰

Conventional prism-type SPR sensors

Conventional prism type SPR sensors

Surface Plasmon Resonance Sensors

시료 불감지 시

Convergent light beam

Photodiode array

시료 감지시

Prism coupler

SPR-active metal

SP

Sample Biomolecular

recognition elements

시료 농도 변화 ~ sensing layer 유전율 변화 ~ SPR 공명각 변화량

- Angle interrogation

- Wavelength interrogation

Best SPR sensor:

BiaCore

Angle interrogation Δn

_min

~3x10

^-7

Large size Large size

Expensive (장비:2억, chip 10만원)

Surface plasmon resonance (SPR) sensor

Concept of SPR Biosensing

Re{ } Im{ }

M D

c

ω ε ε

β β β

ε ε

= = +

M

+

D

c ε + ε

R { } β k ^{k f b}

Re{ } β ≅ ⋅ k n k: free-space wavenumber

Concept of SPR Biosensing

The propagation constant k of the SPW can be determined by measuring changes in one of these characteristics.

angular modulation intensity modulation

wavelength=682nm Angle of incidence 54

^o

SPR imaging

• Spatially-filtered, expanded, l i d H N l

p-polarized HeNe laser beam illuminates the gold sample through a prism coupler

coupler.

• Reflected light from the

gold surface, containing the SPR image, is monitored with a CCD camera.

• The angle of incidence can be changed by rotating the g y g entire sample assembly.

A.J. Thiel et. al., Anal. Chem. 69 (1997), pp. 4948–4956.

2D and 3D Images of ssDNA

•Shows the 5 spots of self Shows the 5 spots of self

assembled thio-oligonucleotide DNA probes immobilized on the gold surface

gold surface

Color variation indicates

•Color variation indicates

variation in the thickness of the self assembled monolayer (SAM)

•R. Rella, et al. Biosensors and Bioelectronics. 20 (2004), pp.1140-1148.

Surface plasmon-polaritons excited on thin metal films Surface plasmon polaritons excited on thin metal films

with IMI (insulator-metal-insulator) structures

IMI (insulator-metal-insulator) structures IMI (insulator metal insulator) structures

Dielectric – ε

₃₃

Metal – ε

₂

Dielectric – ε

₁

When the film thickness becomes finite.

mode

overlap

Long-range SPP and short-range SPP g g g

Long-Range SPP:

Long-Range SPP:

weak surface confinement, low loss

y equenc y fr e

Short-Range SPP:

strong surface confinement, high loss

in-plane wavevector

Extremely long-range SPPs?

Symmetrically coupled LRSPP

cy requen c fr

Anti-symmetrically coupled LRSPP

in-plane wavevector

Dependence of dispersion on film thickness

0 75 1

0 75 1

0 75 1

0 75 1

200 400 600 800

-0.25 0.25 0.5 0.75

200 400 600 800

-0.25 0.25 0.5 0.75

250 500 750 1000 1250 1500

-0.25 0.25 0.5 0.75

250 500 750 1000 1250 1500

-0.25 0.25 0.5 0.75

practically forbidden

-1 -0.75 -0.5

-1 -0.75 -0.5

6 0 h = n m

-1 -0.75 -0.5

-1 -0.75 -0.5

1 0 h = n m

Surface-polariton-like waves guided by thin, lossy metal films

G S ( )

J.J. Burke, G. I. Stegeman, T. Tamir, Phy. Rev. B, Vol.33, 5186-5201 (1986).

Dispersion relations for waves guided by a thin, lossy metal film surrounded by dielectric media

Characteristic of "spatial transients" :

Usual symmetric and antisymmetric branches each split into a pair of waves

Æ one radiative (leaky waves) and the other nonradiative (bound waves).

Symmetric modes: the transverse electric field does not exhibit a zero inside the metal film Antisymmetric modes: the transverse electric field has a zero inside the film.

ε

_m

= - ε

_R

– i ε

_I

h

x ε

₁

m R I

ε

₃

z

Burke, PRB 1986

Dispersion relation for thin metal films (3 layers) obtained from the Maxwell equations

obtained from the Maxwell equations

( )

( , , ) y 0 ( ) exp

i i

H x z t =e H f z ⎡⎣i βx−ωt ⎤⎦

[ ] ( )

[ ] [ ] ( )

[ ] ( )

3

2 0 2

1

exp ( ) in medium 3

( ) exp ( ) exp in medium 2 0

exp in medium 1 0

i h

B s z h z h

f z A s z h A s z z h

s z z

⎧ − − ≥

=⎪⎨ − + − ≤ ≤

⎪ ≤

⎩

2 2 2

0

j j j

s

=

β

−

ε k

( )

[ ]

H j

i ∂ i df z

⎧ − −

[ ]

[ ]

0

0

exp 0

( )

( )exp

y x

j y

z y

j

j

i H i

E H i x

z

i E

E H

d

H i x

f z dz

f z ωε ωε β

ωε β β β

⎧ ∂

= =

⎪ ∂

⎪⎪

= ∇× →⎨ =

⎪ − −

⎪ = =

⎪

E H

[ ]

0 ( ) p

z y

j

fj β

ωε ωε

⎪⎩

[ ] ( )

3 ( )

s B h h

⎧− ≥

⎪

[ ]

[ ] ( )

[ ] [ ]

{ } ( )

[ ] ( )

3

3 3

2

0 2 0 2

2 1

exp ( )

exp exp ( ) exp 0

x h

B s z h z h

s

E iH i x A s z h A s z z h

s ε

ω β ε

− − ≥

⎪⎪

− ⎪⎪

= ×⎨ − − − ≤ ≤

⎪⎪

⎪ ¹

[ ]

1

( )

1

exp 0

s s z z

ε ^≤

⎪⎪⎩

From the boundary conditions,

( )

( )

1 2 2 0

2 3 2 0

0 : exp[ ] 1

: exp[ ]

x x h

x x h

z H H s h A A

z h H H A s h A B

= = ⇒ − + =

⎧⎪⎨

= = ⇒ + − =

⎪⎩

2 1

1 2 2 0

1 2

2 3

2 3 2 0

0 : exp[ ]

: exp[ ]

x x h

x x h

z E E s h A A s

s

z h E E A s h A s B

ε ε

ε

⎧ = = ⇒ − − =

⎪⎪⎨

⎪ = = ⇒ − − = −

⎪⎩ ε^{3 2}s

⎪⎩

⎧⎛ ⎞

From the equations at z = 0, A

_h

, A

_o

, and B can be determined by,

[ ] [ ] [ ] ( )

[ ] [ ] ( )

2 1

2 2 3

1 2

2 1

2 2

1 2

cosh sinh exp ( ) 3 :

( ) cosh sinh 2 : 0

j

s h s s h s z h j z h

s

f z s z s s z j z h

s ε ε ε ε

⎧⎛ ⎞

+ − − = ≥

⎪⎜ ⎟

⎝ ⎠

⎪⎪⎪

=⎨ + = ≤ ≤

⎪exp

[ ]

s z1

(

j 1:z 0

)

⎪⎪ = ≤

⎪⎪⎩

Therefore, anther equations at z = h gives the dispersion relation,

( ^{ε ε}

^{1 3 2}

^s

²

^{+ ε}

²²

^{s s}

^{1 3}

) ^{tanh [ ] s h}

²

^{+ ε}

^{2 2}

^{s ( ε}

^{3 1}

^{s + ε}

^{1 3}

^{s ) = 0}

(

^{1 3 2 2 1 3}

) ^{[ ]}

^{2 2 2}

⁽

^{3 1 1 3}

⁾

2 2 2

0

j j j

s = β − ε k

ε1

εm

H_y ε1

εm

H_y

Two nonradiative, Fano modes

ε3 Bound (a)

m

ε3

Bound (s)

1 3

(1) : S > 0 & S > 0

Symmetric bound (sy ( _bb)) Asymmetric bound (aAsymmetric bound (a_bb))

Surface plasmon dispersion for thin films

Drude model ε

₁

(ω)=1-(ω

_p

/ω)

²

Two modes appear

L

_-

(asymmetric) Thinner film:

L

₊

(symmetric)

Thinner film:

Shorter SP wavelength

Propagation

L

Example:

λ

_HeNe

= 633 nm λ

_SP

= 60 nm

Propagation lengths: cm !!!

(infrared)

L _-

λ

_SP

= 60 nm

2 1 3

1.55 m , 118 i 11.58 , 2.25

λ = μ ε = − + ε = ε =

Ex)

( ^{ε ε}

^{1 3 2}

^s

²

^{+ ε}

²²

^{s s}

^{1 3}

) ^{tanh [ ] s h}

²

^{+ ε}

^{2 2}

^{s ( ε}

^{3 1}

^{s + ε}

^{1 3}

^{s ) = 0}

H

s

_b

a

_b

2 2 2

0

j j j

s = β − ε k

^ε1

εm

ε3

Hy

Bound (a) ε1

εm

ε3

H_y

Bound (s)

2.0 1

a

Bound (s) ( )

1.8 1.9

a

_b

s

_b

k

0

1E 3 0.01

0.1

a

b

s

b

k

0

1.6

β /k

r1.7

1E-5 1E-4

β /k

i 1E-3

0 50 100 150 200

1.5

( )

0 50 100 150 200

1E-7 1E-6

thickness (h : nm)

thickness (h : nm) thickness (h : nm)

Metal stripe waveguides using Metal stripe waveguides using

long-range surface plasmon polaritons(LRSPPs)

SPP waveguide schemes

Si wafer Si wafer

Si wafer

(a) (b) (c)

<Single metallic waveguide> <Double symmetric metallic waveguide> <Double asymmetric metallic waveguide>

Thin metal stripes with a finite width

metal strip

dielectric

Finite film thickness and width

Plasmon-polariton waves guided by thin lossy metal films of finite width: Bound modes of symmetric structures,

P. Berini, Phy. Rev. B, Vol.61, 10484 (2000)

( )

( , , , ) x y z t =

₀

( , ) x y e

^{i β ωz− t}

E E

( )

( , , , ) x y z t =

₀

( , ) x y e

^{i β ωz− t}

H H

E

_o

, H

_o

: polarization direction z-axis : propagation direction

From the Maxwell equations

1 2

r 0

( ε

⁻

) k

∇ × ∇ × H = H

A th t ll di b i t i

1 1 2 2 1

( ε

⁻

) ε

⁻

( ) ( k β ε

⁻

) 0

∇ × ∇ × H ∇ ∇ H H

Assume that all media be isotropic.

The magnetic field on x-y (transverse plane) satisfies

r r 0 r

( ) ( ) ( ) 0

t

ε

t t

ε

t t t

k β ε

t

∇ × ∇ × H − ∇ ∇ ⋅ H − − H =

t

i j

x y

∧

∂

∧

∂

∇ = +

∂ ∂

( )

( )

^{i z t}

t

H i

x

H j e

y ^{β ω}

∧ ∧

= +

−

where H

y

This eigenvalue problem can be solved by a numerical method

with proper boundary conditions, such as one of FDM, FEM, MoL, … Here, we use the FDM (finite difference method).

Here, we use the FDM (finite difference method).

FDM

2 1 3

1.55 m , 118 i 11.58, 2.25, w 5 m

λ = μ ε = − + ε = ε = = μ

Ex)

FDM

y

z y

x

x

y

1.60 1.62 1.64

sa

_b^o

ss

^{o 1E-3}

0.01

1.54 1.56 1.58

β r/k

o

ss

_b^o

1E-5 1E-4

β

i

/k

0

sa

_b^o

0 50 100 150 200

1.50 1.52 1.54

0 50 100 150 200

1E-7

1E-6

ss

b o

0 50 100 150 200

thickness of metal (nm)

0 50 100 150 200

thickness of metal (nm)

Field profile of slab SPP modes

Symmetric Mode

0.8 1.0

)

h=20nm h=40nm h=100nm

h=200nm

0.8 1.0

Symmetric Mode

0.4 0.6

H y(a.u.) h=200nm

0.4 0.6

H y(a.u.)

h=20nm

-4 -2 0 2 4

0.0 0.2

length ( m)

-0.2 -0.1 0.0 0.1 0.2

0.0 0.2

length (μm) h=40nm

h=100nm h=200nm

Field enhancement at the boundary

1.0

h 20 length (μm)

1.0

Anti-Symmetric Mode

y Æ Sensitive to environment

0.0 0.5

h=20nm h=40nm h=100nm h=200nm

(a.u.) y ^0.0

0.5 h=20nm

h=40nm h=100nm h=200nm

H y(a.u.)

-1.0 -0.5

H

-0.2 -0.1 0.0 0.1 0.2

-1.0 -0.5

-4 -2 0 2 4

length (μm)

length (μm)

LRSPP waveguides

Long

Long--Range Surface Plasmon Polaritons WaveguideRange Surface Plasmon Polaritons Waveguide

LR-SPPs W/G Structure LR-SPPs Waveguide Devices

SiO2

LR SPPs W/G Structure S s W vegu de ev ces

Optical modulator & switch

Sergey I. Bozhevolnyi Group (Denmark)

Optical add/drop filter

SiO2 Au

~ 20nm

~ 5um

mode SS

⁰_b

Mode profile of

Bragg grating filter Pi B i i G (C d ) Vertical directional coupler

Pierre Berini Group (Canada) Seok Ho Song Group (Korea)

optical Sensor ?

Best measurements:

- Attenuation: 3.2 dB/cm Attenuation 3.2 dB/cm

- Coupling to SMF: < 0.2 dB

Jung (ETRI), 40 Gbit/s light signal transmission on a long-range SPP waveguide, APL, PTL, 2007.

Plasmonic Flexible-wires for 40 GHz interconnections

LR-SPP waveguide Drive IC

TIA &

Pre amp IC

Tx

VCSEL array

SMA SMA

PD array

R x

14 nm-thick, 2.5 μm-wide gold stripes 5

6

40 Gb/s World best

2 3 4

Loss (dB)

λ= 1310 nm

0.5 1.0 1.5 2.0 2.5

0 1

Waveguide length (cm)

0.6 dB/cm : World best record in propagation loss.

(Previous world record : 3.2 dB/cm by Berini, 2006)

Double-electrode metal waveguides : Lines, S-band, Y-branch

Joo, Long-range surface-plasmon--polaritons on asymmetric double-electrode structures, APL, 2008.

ε

_d3

ε

₂

D

SPP mode w metal strip

ε

_d3

D

metal slab

core cladding

ε

_d1

metal strip

Y-branch S-band

p metal slab

LRSPP waveguide sensors

LRSPP waveguide sensors

LRSPP bio-sensor chips

D

SPP mode metal strip

Bio-fluidics

SPP mode

metal slab

SERS & 대장균

S ilve r n a n o p a rticle S ilve r c o llo id

A n a lyte

La se r &

d e te ctio n p o int Nano 구조물

Analog

Analog WGPD

LD (TM polarized)

폴리머 or 실리카 도파로

A n alyte S ilve r

n a n o c lu sters

37 37

g M-WGPD

실리콘 기판

Sensing area (Cr 10nm, Au 50nm)

NPIC chip

LRSPP Waveguide Sensors

Long

Long--Range Surface Plasmon Polaritons Waveguide SensorRange Surface Plasmon Polaritons Waveguide Sensor

Output signal

150 200 250 300 350

nsity (uW)

p g

M t l id

1.330 1.331 1.332 1.333 1.334 1.335 1.336 0

50 100

Inte

Refractive index of water

R f S i

Metal waveguide Reference arm Sensing arm

Metal waveguide sensor Dielectric waveguide sensor

- Air or water background - Polarizing waveguide

-

Higher waveguide sensitivity

g e ec c w vegu de se so

- Air or water background - Non polarizing waveguide

- Higher waveguide loss

: Hybrid waveguide structure

-

Added functionality

: In situ heating or electric field

-

Low waveguide sensitivity

-

Lower waveguide loss

-

No added functionality

: In situ heating or electric field

y

LRSPP Waveguide Sensors

Region 1 Region 2 Region 1 Cross Section

em

, d

em

ε ε

_Au

, d

_Au

~ 1.47( )

nclad dielectric

R f S i

Region 2 Cross Section d ε

_A

, d

_A

Metal waveguide

Reference arm Sensing arm ε

_em

, d

_em

ε

_Au

, d

_Au

~ 1.33( ) n

sens

water

Liquids

(ex. Bio-molecules)

( )

Sensitivity of LR-SPP Waveguide Sensor

, (variable)

a da

ε

Index change by thermal/density

ε d

εc em,dem

ε

Au,dAu

ε

Index change

(varialbe) εc

em,dem

ε

Au,dAu

ε

by thichness

Almost 1

1 3317 1.3318

d =50nm

1 340 1.342

d =50nm

1.91 10 /

5 eff

a

n nm

d

∂

−

= ×

∂

0.99465

eff c

n n

∂ =

∂

1.3316

1.3317 d

em=50nm

N sens

1.336 1.338

1.340 d_em 50nm

N sens

0 2 4 6 8 10 12 14 16 18 20 22

1.3314 1.3315

1.330 1.332 1.334 1.336 1.338 1.340 1.330

1.332 1.334

thickness of d

a(nm)

1.330 1.332 1.334 1.336 1.338 1.340 index(n_c)

Mach-Zehnder Interferometer type

4~20μm

SiO₂

Carrier fluid Sensing arm SiO₂

Au 15~25 nm

SiO₂

Au

15~25 nm Si₃N₄ membrane

Receptor Carrier fluid

with analyte

Substrate Substrate

Laser Detector

Receptor

300 350

Carrier fluid

with analyte Reference arm

50 100 150 200 250

Intensity (uW)

I

‹ Reference arm compensates

- thermal and strain variations along the device - changes in carrier fluid index

1.330 1.331 1.332 1.333 1.334 1.335 1.336 0

Refractive index of water

Refractive Index

g

- non-specific binding

‹ Monolithic integration of micro-fluidic and electronics potentially possible

MZI Sensor sensitivity

Sensing arm Sensing arm

L 250

300 350

uW)

I

1.330 1.331 1.332 1.333 1.334 1.335 1.336 0

50 100 150 200

Intensity (u

I

0 2 3

Reference arm

Binding of bio-molecules on sensing arm Æ Mode effective index change sensing arm

Refractive index of waterΔφ

0 π 2π 3π

L n

_eff

Δ

= Δ φ 2 π

Æ Mode effective index change sensing arm

Æ Mode propagation phase difference (Δφ) between sensing and reference arms

Æ Phase difference is converted to intensity variation

( )

( )

_⎥⎦^⎤

⎢⎣⎡ + Δ +

= 1 cos ₀

2 log 1

10

φ φ

I

Æ Phase difference is converted to intensity variation

ÆSensitivity

C a a n n

I C

y I

Sensitivit

^eff

eff

∂

∂

∂

∂

∂

∂

∂

= ∂

∂

= ∂ φ

φ

MZI 2πL/λ waveguide receptor

MZI-LRSPP Sensor Design

1000 mμ 2

In Out

40 m

μ 1

1000 mμ 500 mμ 500 mμ 2000 mμ 500 mμ 500 mμ 1000 mμ

Cross section 2 Cross section

1 ^Metal

SiO2

5 m

μ

20nm 100nm

SiO2

Receptor

dielectric dielectric

SiO2(1.47) Air(1.0) SiO2

water metal

SiO2

membrane 1

substrate

membrane 2

Sensitivity

400 500

300 350

300 400

ity (uW)

200 250 300

ty (uW)

100 200

Intens

50 100 150

Intensi t

0 10 20 30 40 50

0

Thickness of water (nm)

1.330 1.331 1.332 1.333 1.334 1.335 1.336 0

Refractive index of water

If a detector has 0.1 uW sensitivity, 3 pm thickness variation can be detectable

If a detector has 0.1 uW sensitivity, 3x10^-7 index difference can be detected

detectable. detected

Dielectric/metal Hybrid MZI

1000 mμ

In Out

λ=780 nm: 5mW dielectric metal dielectric

1000 mμ 1000 mμ 1000 mμ 2000 mμ 1000 mμ 1000 mμ 1000 mμ

Coupling Loss : Fiber-Dielectric WG : ~ 1.26 dB

3 mμ ^{3 mμ}

s 1.45 n =

a

Loss Layer structures

Insertion Loss : Y-junction : ~ 0.5dB

Coupling Loss : Dielectric WG-Metal WG : ~0.6dB

s 1.45 n=

core 1.49

n = ^{0.4 mμ}

50nm

50nm 15nm

1.333 ncl=

em 1.49 n =

h a

Y-Branch : ~ 3dB

Propagation Loss of Metal WG : ~ 8.5dB/mm Propagation Loss of Dielectric WG : ~ 0.02dB/mm

10 m5 μ 10 m5 mμμ

5 mμ

Total Loss : ~ 15 dB

Double-layered LRSPP waveguide type

Bio contents contents SAM

Channel area

Dielectric material

Cladding

Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y

Y

< Double LR-SPP biosensor >

Metal (Au) Substrate

Cladding

Strip configurations

Mach-zender interferometers Directional couplers

Directional couplers DFB gratings

Substrate

Bragg grating

y

LRSPP waveguides sensors with a μ-fluidic channel

(a)

y z

x

μ-fluidic channel metal strip

core cladding

silicon wafer core

cladding

metal slab

450 nm

(b) (c)

cladding cladding

450 nm

cladding cladding

(d) (e) (f)

Bragg grating

μ-fluidic channel

Bragg grating

2 2 2

loss max

Total Loss, T (dB) = 10 log( × η η η _c × × × _{w g} R )

Ci l

loss max

, ( ) g( η η η _{c w g} )

Propagation loss in waveguide region

L_w L L

Circulator Input

signal

Reflectance of grating ( R_max)

L_w L_g L_w

Substrate

L_g

L_w L_w

Outputsignal

Coupling loss Propagation loss in grating region Detectable range

45 50

" (dB)

20nm 40nm

60 ^{0 8}

1.2 1.6

, Δt min (nm)

20nm 40nm 60nm 80nm 1 nm

30 35 40

o ss "T

loss 60nm

80nm

Detection limit

0.0 0.4 0.8

Resolution

0 2 4 6 8 10

15 20 25

Total L o

_{0 2 4 6 8 10}^{0 0}

Grating length, Lg (mm)

Î grating length : 2 mm ~ 5.5 mm

0 2 4 6 8 10

Grating length, Lg (mm) Î resolution : 0.36 nm

with a 40 nm grating depth.

Î 1.6×10^-5 RIU

Comparison of sensor types

SPR in ATR LRSP Waveguide MZI Dielectric Waveguide MZI

Archi- tecture

angle/wavelength scan in ATR Phase difference detection in MZI Phase difference detection in MZI

Sensing layer Polarizati

TM TM TE and TM

Metal on high index prism

Metal on membrane waveguide

Dielectric waveguide

on TM TM TE and TM

Sensitivity High Higher Higher

Optical High Lower Lowest

Optical loss

High (ATR required)

Lower (MZI possible)

Lowest (MZI)

size

Bulk optics

(Larger amount of analyte

Integrated Optics (Smaller amount of analyte,

Integrated Optics (Smaller amount of analyte, Difficult to make array) Easy to make array) Easy to make array) Sensing

Surface Au Au Dielectric

Added

function - In situ heating

Electrical signal transmission -

Final comments

1. How do we define the dispersion relations of SPPs excited on thin metal films and stripes?

2. What are the long-range SPPs and short-range SPPs?

2. How can we implement LRSPP waveguide devices?

Key notes

SPP wires : Bio-sensors ERC OPERA

p g

4. What are the merits of the LRSPP waveguide-type sensors?

SPP wires : Inter-chip interconnects

Next lecture at 07/21

(06/23) Introduction: Micro- and nano-optics based on diffraction effect for next generation technologies (06/30) Guided-mode resonance (GMR) effect for filtering devices in LCD display panels

(07/07) Surface-plasmons: A basic

(07/14) Surface-plasmon waveguides for biosensor applications

(07/21) Efficient light emission from LED, OLED, and nanolasers by surface-plasmon resonance

(Appendix) GMR grating sensors

(Appendix) GMR grating sensors

Guided-mode resonance sensors

Concept

I R ^{Link Layer}

Receptor

Chemical Agents

I R

Grating Link Layer

GMR Structure

Selective sensing enabled with standard biochemical recognition i

Structure

reactions

-Antigen/antibody, enzyme-substrate, ligand-receptor, DNA

- No fluorescent/absorption tags required

Guided-mode resonance sensor Guided mode resonance sensor

technology

Fast - instant results

Outstanding accuracy – cross referenced

data

(1) (2)

High sensitivity – detection of small molecules to large bacteria

High resolution – sharp detection peaks, high signal to noise

( ) Baseline

(2)

After analyte binds

Δλ

tance

Mass producible – high density formats

Initial market applications in drug discovery and proteomics:

i ib d id d

Reflec t

Sensor element

•

Antigen-antibody assays, peptides and cell-based assays, DNA arrays

Wavelength ( ^λ )

Captured biomolecules ⇒ Change in reflected color of light

g ( )

g g

Prototype sensor system Prototype sensor system

A biosensor system consisting of a disposable array plate integrated with guided-mode A biosensor system consisting of a disposable array plate integrated with guided-mode

resonance (GMR) elements, and

(sensor in bottom of array plate)

a fiber-optic detection instrument for read-out and quantified binding response

array plate)

Incident

b db d

Narrowband reflected light Sensor element

Optical fiber-lens assembly

broadband light

reflected light

Spectrum Analyzer Input

Broadband Light

Water test of sensor head

0.8 0.9 1

0.8 0.9 1

0.3 0.4 0.5 0.6 0.7

Transmission

Resonant shift ~ 16.5 nm air

water

0.3 0.4 0.5 0.6 0.7

Transmission

Resonant shift ~ 16.5 nm air

water air

water

Theory

0 0.1 0.2 0.3

735 745 755 765 775 785 795 805 815 825

Peak in water ~ 797 nm Peak in air ~ 780.5 nm

0 0.1 0.2 0.3

735 745 755 765 775 785 795 805 815 825

Peak in water ~ 797 nm Peak in air ~ 780.5 nm

Wavelength (nm) Wavelength (nm)

0.8 0.9

) 0 16

0.17

u.)

0.8 0.9

) 0 16

0.17

u.)

0.4 0.5 0.6 0.7

sion in air (a.u.)

0.14 0.15 0.16

on in water (a.u

air water 0.4

0.5 0.6 0.7

sion in air (a.u.)

0.14 0.15 0.16

on in water (a.u

air water air

water

Experiment

0.1 0.2 0.3 0.4

Transmiss

0.12 0.13

Transmissi

Peak in water

~ 797.6 nm Peak in air ~ 780.5 nm

Resonant shift ~ 17.1 nm

0.1 0.2 0.3 0.4

Transmiss

0.12 0.13

Transmissi

Peak in water

~ 797.6 nm Peak in air ~ 780.5 nm

Resonant shift ~ 17.1 nm

Peak in water

~ 797.6 nm Peak in air ~ 780.5 nm

Resonant shift ~ 17.1 nm

pe e

0

735 755 775 795 815

Wavelength (nm) 0 0.11

735 755 775 795 815

Wavelength (nm)

0.11

B t i l tt h t h

Bacterial attachment scheme

Blocking protein Antibody

S. aureus bacteria (1 μm)

Silane layer xxx Grating element

P Sil t d ti f bi d tib di th t tt h t t i A ( f t i S

Process: Silane-coated grating surface binds antibodies that attach to protein A (surface protein on S. aureus bacteria). Milk protein added to block nonspecific binding of S. aureus to unoccupied silane sites.

Chemistry steps provided in Magnusson et al, Proc SPIE vol. 6008, pp. 60080U 1-10, 2005.

Measured results Measured results

Period~500 nm

6

7 ~1.5 nm shift

4 5

bitrary units)

Phosphate buffered saline

After S. aureus+milk incubation

3 4

ectance (arb

1

Refle 2

780 782 784 786 788 790 792 794 796 798 800 0

W l th ( )

Wavelength (nm)

M d ti th d Mass production method

Imprint lithography in polymers

Master: Si grating via UV holographic interferometry

59

Next generation: Integrated GMR biochips

Angular addressing, laser source, transmission

Microwell plates

Platform holding an NxM detector matrix

GMR Sensor

Microlens Array

Plane Wave

Estimated density~100x100 elements/cm²

60