INTERNSHIP PRESENTATION

DEBASMIT DASENROLLMENT NO. – 10115039

BATCH E3

DETAILS ABOUT MY INTERNSHIPTYPE – RESEARCH INTERNSHIPPLACE – ECOLE POLYTECHNIQUE DE

MONTREALFIELD – PHOTONICSGUIDE – DR. RAMAN KASHYAPLAB- ADVANCED PHOTONICS CONCEPTS

LABORATORYDURATION – 13TH MAY TO 19TH JULY, 2013

CONTENTS OF MY INTERNSHIPFABRICATION OF A 4-PORT OPTICAL FIBER

COUPLEREXPERIMENTAL AND THEORITICAL

ANALYSIS OF SURFACE PLASMON DEVICES (SPR) BASED ON OPTICAL FIBER

FABRICATION OF A 4-PORT OPTICAL FIBER COUPLERAIM OF THIS PROJECT IS TO BUILD A

COUPLER THAT CAN BE USED MULTIPURPOSELY FOR DIFFERENT PROJECTS IN THE FUTURE.

I APPLIED THE COUPLER TO OBTAIN THE REFLECTION AND TRANSMISSION SPECTRUM OF A TILTED FIBER BRAGG GRATING.

DETAILS ON THESE IN THE COMING SLIDES……

FIBER OPTIC COUPLER

Coupler used to direct light into the Fiber Bragg Grating.LC=Coupling Length ; LW = Waist Length ; LT = Taper length

Plot of power P1-3 (red) P2-4 (green) with distance along coupling length

P1-3 (Power in wave guide 1 to 3) = cos2(kz) P2-4(Power in wave guide 2 to 4) = sin2(kz)

FBG and tilted FBGResonance condition for FBG λB = 2nt

For tilted FBG the condition holds as λB = 2nt cos (x) where x is the angle of tiltBut why is the tilted FBG?Because my fiber is DCF (double clad fiber)

Schematic of the Coupler I am to produce

StepsEtching of two DCF fibers around 15 cm

lengthTwisting of the two fibers along the etched

portion.Fixing the coupler to a platform to make it

ready for measurementsCharacterization of the coupler and

observing the spectrum of the tilted FBG

DCF before being etched DCF after being etched

CharacterizationExcessive Loss = -10 log(P1+P2/Pin)CR = P2/P1+P2 x 100 % (Coupling Ratio)For 6 Twists – Pin= 12.35dBm P1=10.45 dBm P2=-32.45 dBm  So excessive Loss = 1.5497 dB CR=0.005688 %

Reflection and Transmission Spectrum

SURFACE PLASMON RESONANCEAIM OF THIS PROJECT IS SIMULATION

AND ANALYSIS OF SPR ON A NOVEL H-SHAPED FIBER

SIMULATION HAS BEEN DONE IN MATLABPURPOSE OF SIMULATION IS TO ANALYSE

AND COMPARE WITH EXPERIMENTAL RESULTS

PHENOMENON OF SPR

k*ng *sinθ = k((ns2*εm)/( ns

2 + εm ))^0.5

MOMENTUM TRANSFER CONDITION

APPLICATIONAs a biosensor or a chemical sensorAs refractive index of sensing medium changes so

will the resonance wavelengthSo the resonance wavelength can plotted with

refractive index and this calibration is used to create biosensor

It can indirectly be used to measure concentration of analyte which perturbs refractive index

ADVANTAGE : Very high sensitve sensors ~ 3000 nm/RIU . Apt for the nano world.

The Special H-shaped fiber

Why H-shaped Fiber?Birefringent fiber with elliptical coreTwo orthogonal single modes with no

interference in visible region.Can be used to measure two quantities

simultaneouslyBut for now analysis is done for one axis that

is the axis along the cleavage….

N-Layer Model ParametersN=3 for our casesn1=core n2=metal n3=dielectric sensing

medium Core diameter =10 nm Metal thickness (gold)

=50 nm and Dielectric thickness = 25 nm

0.4 0.5 0.6 0.7 0.8 0.9 10.1

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Wavelength (nm)

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THANK YOU !!

SPECIAL THANKS TO MITACS FOR FUNDING THE INTERNSHIP