Enhanced nonlinear optical response of 1-D metal-dielectric photonic - - PowerPoint PPT Presentation

Enhanced nonlinear optical response of 1-D metal-dielectric photonic band-gap structures

Nick N. Lepeshkin, Aaron Schweinsberg, Ryan S. Bennink, Robert W. Boyd The Institute of Optics, University of Rochester, Rochester, NY 14627, USA Robert L. Nelson Materials and Manufacturing Directorate, Air Force Research Laboratory, (AFRL/MLPO) Wright-Patterson Air Force Base, Ohio 45433-7707 and The Institute of Optics, University of Rochester, Rochester, New York 14627

Outline

• 1. Motivation

How to access nonlinearity of metals? Why 1-D MD-PBG? Optical transparency Nonlinear response?

• 2. How to Design 1-D MD PBG for NLO
• 3. Linear properties
• 4. Elements of nonlinear response

High EM field strength Intrinsic susceptibility of metal Phase response of PBG

• 5. Experimental observation of enhancement of

NLO response in 1-D MD PBG

How to access nonlinearity of metals?

• paque!
• esu

10 10

7 8 ) 3 ( − − ÷

≅

metal

χ esu 10 14

) 3 (

2

−

≅

SiO

χ

• transparent!
• colloidal solutions
• metal doped glasses
• granular metal films

Discontinuos composite materials: Layered periodic MD structures: High transparency within specified spectral range (PBG effect) Enhanced NLO response?

1-D Metal/Dielectric PBG structures 3

80 nm Cu film

1 2

40/389 nm Cu/SiO2 FP

3

5 x 16/98 nm Cu/SiO2 PBG

2% 22% 50%

• M. Scalora et al. J. Appl. Phys. 83, 2377-2383 (1998)

0.2 0.4 0.6 500 600 700 800 Wavelength, nm T 2 1

How to Design 1-D MD PBG for NLO

2 ) 3 (

E F

m lin

⋅ ⋅ ⋅ + ≅ η χ ε ε

factor field − η

F- phase factor

5 x 16/196 nm Cu/SiO2 PBG

nm 650 = λ

2

E

z, nm

Linear optical properties

0.05 0.10 0.15 0.20 0.25 400 500 600 700 800 900 Wavelength, nm Transmittance 1- 40 nm Cu film - bulk 2- 5 x 16/98 nm Cu/SiO2 PBG - composite

1 2

0.2 0.4 0.6 0.8 1.0 500 550 600 650 700

A R T

0.1 0.3 0.5 0.7 500 550 600 650 700

A T R 1 2

1 - 5 x 16/98 nm Cu/SiO2 PBG 2 - 40 nm Cu film 0.5 1.0 1.5 2.0 2.5 500 550 600 650 700 Wavelength, nm

High EM field strength

2 2 Cu PBG

E E

1 2

Nonlinear susceptibility of bulk metal

NLO properties of copper @ interband threshold -

2 ) 3 (

) 1 ( ) Im(

T k E T k E B FS

B B

e e T k E C

δ δ

δ χ

− −

+ =

Fermi smearing

• F. Hache et al. Appl. Phys. A 47, 347-357 (1988)

ν δ h E E

g −

=

FS FS

) Im( ) Re(

) 3 ( ) 3 (

χ χ <<

nm 580 @ esu 10 4

8 −

⋅

Eg=2.15 eV

nm 640 @ esu 10 2

9 −

⋅

) Im(

) 3 (

χ

nm , λ

T k E hc

B g FS 2

≅ ∆λ

1x10

• 8

2x10

• 8

3x10

• 8

4x10

• 8

5x10

• 8

550 600 650 700

Phase response

1 2 3 4 5 6 500 550 600 650 700 Wavelength, nm |F|

∫ ∆

∆ =

L

dz n F 2 λ π φ

• phase sensitivity

NLO response of MD PBG

) ) ( ln( ) (ln( I T T i

lin −

⋅ + ′ = φ δ δφ

• complex nonlinear phase shift

EKSPLA OPG E=2-5 uJ I=100 MW/cm2 t=25 ps

scan

• Z

← δφ

nm 640 ? MW/cm 500 I

2

= =

φ δ φ δ ′ ′ << ′

nm 680 540 ? − =

35 ≅ ′ ′ ′ ′

Cu PBG

φ δ φ δ

0.5 1.0 1.5 2.0 500 550 600 650 700

Wavelength, nm Im(δφ)

0.50 0.75 1.00 50 100 150 200 250 z,mm Tnorm

PBG Cu PBG Cu

Conclusions We experimentally demonstrated enhanced nonlinear response of 1-D MD PBG structure within the passband compared to that of bulk metal. The enhancement factor was measured to be as high as 35. We introduced artificial, stable, solid state NLO material with tunable (by design) transmission band and high damage threshold.