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Title: Theoretical and experimental investigations of asymmetric light transport in graded index photonic crystal waveguides

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4861926· OSTI ID:22280600
; ;  [1];  [2];  [3]
  1. Nanophotonics Research Laboratory, Department of Electrical and Electronics Engineering, TOBB University of Economics and Technology, Ankara 06560 (Turkey)
  2. Electrical and Electronics Engineering Department, Ankara University, Gölbasi, Ankara 06830 (Turkey)
  3. Department of Electrical and Electronics Engineering, Bilkent University, Bilkent, Ankara 06800 (Turkey)

To provide asymmetric propagation of light, we propose a graded index photonic crystal (GRIN PC) based waveguide configuration that is formed by introducing line and point defects as well as intentional perturbations inside the structure. The designed system utilizes isotropic materials and is purely reciprocal, linear, and time-independent, since neither magneto-optical materials are used nor time-reversal symmetry is broken. The numerical results show that the proposed scheme based on the spatial-inversion symmetry breaking has different forward (with a peak value of 49.8%) and backward transmissions (4.11% at most) as well as relatively small round-trip transmission (at most 7.11%) in a large operational bandwidth of 52.6 nm. The signal contrast ratio of the designed configuration is above 0.80 in the telecom wavelengths of 1523.5–1576.1 nm. An experimental measurement is also conducted in the microwave regime: A strong asymmetric propagation characteristic is observed within the frequency interval of 12.8 GHz–13.3 GHz. The numerical and experimental results confirm the asymmetric transmission behavior of the proposed GRIN PC waveguide.

OSTI ID:
22280600
Journal Information:
Applied Physics Letters, Vol. 104, Issue 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English