Toward hybrid polymer-porous silicon waveguides for Vernier-effect optical biosensors

(1)

HAL Id: hal-01891918

https://hal.archives-ouvertes.fr/hal-01891918

Submitted on 18 Oct 2018

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Toward hybrid polymer-porous silicon waveguides for

Vernier-effect optical biosensors

Paul Azuelos, Nathalie Lorrain, M. Guendouz, Parastesh Pirasteh, Jonathan

Lemaitre, Isabelle Hardy, Joël Charrier, Monique Thual

To cite this version:

Paul Azuelos, Nathalie Lorrain, M. Guendouz, Parastesh Pirasteh, Jonathan Lemaitre, et al.. Toward hybrid polymer-porous silicon waveguides for Vernier-effect optical biosensors. 11th Porous Semicon-ductors - Science and Technology 2018 Conference (PSST 2018), Mar 2018, La Grande Motte, France. �hal-01891918�

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Toward hybrid Polymer-Porous silicon waveguides

for Vernier effect optical biosensors

P.Azuelos

a

, N.Lorrain

a

, M.Guendouz

a

, P.Pirasteh

a

,J.Lemaître

a

,

I.Hardy

b

,J.Charrier

a

and M.Thual

a

_{UMR FOTON, Université de Rennes 1, France}

b

_{UMR FOTON, IMT Atlantique, France}

Introduction on integrated MR

• Microresonator sensing

τ

τ'

κ

κ'

E

_i

E

_t

FWHM

λ

_res

FSR

Δλ

_res

|T(

λ

)|

2

λ

no analytes

presence of analytes

R

Lc

Sensor performance evaluation with

Sensitivity and

Limit of Detection :

S =

∆λ

res

∆C

_analytes

LOD =

N oises

S

Main economic field : Health, Research, Industrie,

Biodefense, Environnemental

• PSi for surface sensing

Bulk

core

Bulk

cladding

Substrate

Grafted

molecules

EM

Field

Porous

core

Porous

cladding

Evanescent detection

Volume detection

PSi advantage : High sensing sensitivity

Bulk material advantage : Low propagation losses

Porous silicon MR fabrication

• Thermal treatment of PSi

Partial oxidation remove native hydrophobicity,

im-prove PSi layers stability in time and tune RI

• Photolithography and etching

UV exposure

development

of photoresist

dry etching

of core waveguide

Photoresist resin

Core

Optical conﬁnment layer

Si-Substrate

Core

Si-Substrate

Optical conﬁnment layer Optical conﬁnment layer

Ion bombardment

Insolation

of photoresist

solvant

• PSi MR sensor

P+ Boron doped Si (5mΩ.cm

−1

) ; Current density

applied : (Core/Cladding) (

50/80) mA.cm

−2

; HF sol.

prop. HF(50%)/ethanol/water :

2:2:1.

Sensor characterisation

• Experimental setup

Fiber-waveguide coupling

with microlens

Peltier thermostat

Sample

Tunable laser

Tin λi(t) wavelength scan

Power-meter

λ

λi(t)

T

out λ

• PSi MR homogeneous sensitivity

cha-racterisation

Optimization of ridge PSi waveguides dimensions

Losses evaluation in PSi waveguides

• Choice of PSI porosity and

oxidation rate

nonox

300°C

500°C

750°C

850°C

oxydation

Current density (mA.cm-2₎

10 30 50 100

Electropolishing

Full pore ﬁlling

after oxidation

Low current

density

0 0 0 0.1 0.1 0.1 0.2 0.2 0.2 0.3 0.3 0.3 0.4 0.4 0.4 0.5 0.5 0.5 0.6 0.6 0.6 0.7 0.7 0.7 0.8 0.8 0.8 0.9 0.9 0.9 1 1 1

f

air

f

Si

f

Si0 2 Studied oxidation (500°C(1h)) - fsiO2<30% - no hydrophobicity

2

_SD

1

SD

n

_core

n

cladding

Δn

0.16 0.54 1.35 1.35 1.51 1.89 (RIU)

• Determination of losses with

waveguide dimensions

10

1

SD

2

SD

4

3.5

3

2.5

2

1.5

1

0.5

0

0.5

1

1.5

2

2.5

3 3.5 4

Overall Losses TE00

Surface Detection

dB/cm

Width (μm)

Heigth (

μ

m

)

5

15

20

25

30

35

40 Sensitivity and Limit of detection

• Sensitivity of PSi MR

1

_SD

2

_SD

4

3.5

3

2.5

2

1.5

1

0.5

0

0.5

1

1.5

2

2.5

3 3.5 4

Sensitivity TE00

nm/(pg.mm-2)

0.02

0.025

0.03

0.04 Width (μm)

Heigth (

μ

m

)

0.035

• Limit of detection

4

3.5

3

2.5

2

1.5

1

0.5

0

0.5

1

1.5

2

2.5

3 3.5 4

LOD TE00

pg.mm-2

0

0.5

1

1.5

2

2.5

3

3.5 Width (μm)

Heigth (

μ

m

)

4 Optimized performances :

S=0.04 nm/(pg.mm

−2

)

LOD=0.5 pg.mm

−2

Toward hybrid Vernier effect

Vernier eﬀect : Cascaded micro-resonators

T

_sens

λ

Tin

One micro-resonator

λ

T

sens

Ligth input

Ligth output

T

ref

T

sens

T

ref

.T

sens

SU8 waveguide

PSi waveguide

adiabatic taper

reference

Micro-resonator

Analytes sensitive Micro-resonator

λ

Tin 100 μm

SU8

waveguide

PSi waveguide

MEB illustration of hybrid

polymer-PSi MR

Sensitivity : ×10

3 LOD : ÷10

2 Vernier effect can improve sensor performances

with a reference interferometer

Conclusion and Perspective

• MR integrated sensor sensitivity and

LOD

0.01

0.1

1

10

100 1E-5

1E-4

1E-3

0.01

0.1

1

10 bulk ridge MR (exp)

bulk slot MR (exp)

PSi MR (sim)

Hybrid PSi-Polymer Vernier (sim)

S

e

ns

itiv

ity

(

nm/

(

pg.mm

-2

))

Limit of detection (pg.mm-2)

[1]

[*]

[4]

[3]

[6]

[5]

[2]

* Simple PSi MR

[1] P.Azuelos & al. JAP 121 144501 (2017) [2] C.F.Carlborg & al. Lab on CHip 10(3) (2010)

[3] M.S.Luchansky & al. Biosens. & Bioelec. 26(4) (2010) [4] K.D.Vos & al. Opt. Exp. 15(12) (2007)

[5] C.A.Barrios & al. Opt. Lett. 33(7) (2008) [6] K.D.Vos & al. Biosens. & Bioelec. 24(8) (2009)