16.20 04 j anthony
DESCRIPTION
Research 3: J AnthonyTRANSCRIPT
Terahertz pulses propagation in microstructured photonic crystal
fibers
Jessienta Anthonya*
Rainer Leonhardta, Maryanne C. Largeb, Alexander Argyrosb, Sergio Leon-Savalb
NZIP Conference 2011
a Physics Department, The University of Auckland, Auckland, NEW ZEALAND
b Institute of Photonics and Optical Science (IPOS), School of Physics, The University of Sydney, Sydney NSW, AUSTRALIA
Outline
• Introduction to terahertz (THz)• How to generate & detect THz?• Guiding the invisible THz in THz
PCFs• Summary
What is THz?
• THz = Far-infrared = sub millimeter• Frequency range = .1 to 10 THz
( ~ 3 cm - .3 m)• Transparent to most materials:
Plastics, clothing...• Reflected by metals, absorbed by
water
Experimental Method
• Coherent, pulsed THz-TDS setup
THz symmetric-pass lens design : Lo & Leonhardt, Opt. Expr. 16, 15991 (2008)
THz Photonic Crystal Fibers• Solid core PCFs: High index guiding
HDPE tube + rings PCF
Han et. al,APL 80, 2634 (2002)
Large mode area Topas® PCF
Nielsen et. alOpt. Expr. 17, 8592
(2009)
Zeonex® PCFAnthony et. al
JOSA B 28, 1013 (2011)
THz Photonic Crystal Fibers• Solid core PCFs: High index guiding
•
• Air core PCFs: Photonic bandgap guidance
HDPE tube + rings PCF
Han et. al,APL 80, 2634 (2002)
Large mode area Topas® PCF
Nielsen et. alOpt. Expr. 17, 8592
(2009)
Zeonex® PCFAnthony et. al
JOSA B 28, 1013 (2011)
Ring-structured BraggPMMA PBGFPonseca et. al
Opt. Lett. 33, 902 (2008)
Kagome (‘Eye of the basket’)PMMA MOFsAnthony et. al
Opt. Expr. 19, 18470 (2011)
THz Photonic Crystal Fibers• Solid core PCFs: High index guiding
•
• Air core PCFs: Photonic bandgap guidance
HDPE tube + rings PCF
Han et. al,APL 80, 2634 (2002)
Large mode area Topas® PCF
Nielsen et. alOpt. Expr. 17, 8592
(2009)
Zeonex® PCFAnthony et. al
JOSA B 28, 1013 (2011)
Ring-structured BraggPMMA PBGFPonseca et. al
Opt. Lett. 33, 902 (2008)
Kagome (‘Eye of the basket’)PMMA MOFsAnthony et. al
Opt. Expr. 19, 18470 (2011)
Zeonex Microstructured Fibers
• High index guidanceModified total internal reflection
• Material: Zeonex (n = 1.52; = .13 cm-1)
• Core diameter = 400 m;air filling fraction = 82%
Results
• Temporal evolution of fundamental mode in Zeonex fibers
Results
• Measured loss limited only to material loss, negligible waveguide loss.
Results
• Normal, low dispersion THz propagation as confirmed by model & simulations
Kagome Microstructured Fibers
• PMMA rings in a triangular pattern• Fabrication: Stack-and-draw preform• Core diameters: 1.8 mm, 2.2 mm• Strut thickness: ~55 m, ~65 m
Guiding mechanism of kagome
• Inhibited coupling: Minimized mode overlap of core mode and cladding mode
• Loss characteristics: Determined by the strut thickness and index contrast
• Spectral properties similar to ARROW*: High transmission loss due to modes supported by cladding solid struts
Anti-Resonance Reflecting Optical Waveguide[Litchinitser et al., Opt. Expr. 11, 1243 (2003)]
Results
• Temporal evolution of guided THz pulses in Kagome fibers
Results
• Kagome measured attenuation coefficient: < 0.6 cm-1
Results
• Kagome mode scans: Fundamental mode only
Results
• Kagome mode scans: Fundamental mode only, good agreement with simulations
Results
• Phase index: Below unity, no coupling to modes in Kagome cladding
Results
• Wider transmission window; low dispersion THz propagation
Summary
Introduction to THz, THz-TDS, THz PCFs
High index guiding in Zeonex PCFInhibited coupling in kagomeCharacterize PCFs with THz-TDSDiscussion of results: Loss spectra,
fundamental mode air-guidance.PCFs open avenue towards low loss
THz waveguides
Thank you