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Optics Letters


  • Vol. 37, Iss. 13 — Jul. 1, 2012
  • pp: 2604–2606

Terahertz bandwidth all-optical Hilbert transformers based on long-period gratings

Reza Ashrafi and José Azaña  »View Author Affiliations

Optics Letters, Vol. 37, Issue 13, pp. 2604-2606 (2012)

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A novel, all-optical design for implementing terahertz (THz) bandwidth real-time Hilbert transformers is proposed and numerically demonstrated. An all-optical Hilbert transformer can be implemented using a uniform-period long-period grating (LPG) with a properly designed amplitude-only grating apodization profile, incorporating a single π-phase shift in the middle of the grating length. The designed LPG-based Hilbert transformers can be practically implemented using either fiber-optic or integrated-waveguide technologies. As a generalization, photonic fractional Hilbert transformers are also designed based on the same optical platform. In this general case, the resulting LPGs have multiple π-phase shifts along the grating length. Our numerical simulations confirm that all-optical Hilbert transformers capable of processing arbitrary optical signals with bandwidths well in the THz range can be implemented using feasible fiber/waveguide LPG designs.

© 2012 Optical Society of America

OCIS Codes
(060.2340) Fiber optics and optical communications : Fiber optics components
(070.1170) Fourier optics and signal processing : Analog optical signal processing
(230.1150) Optical devices : All-optical devices
(320.5540) Ultrafast optics : Pulse shaping
(070.7145) Fourier optics and signal processing : Ultrafast processing

ToC Category:
Fourier Optics and Signal Processing

Original Manuscript: February 28, 2012
Revised Manuscript: April 27, 2012
Manuscript Accepted: May 1, 2012
Published: June 22, 2012

Reza Ashrafi and José Azaña, "Terahertz bandwidth all-optical Hilbert transformers based on long-period gratings," Opt. Lett. 37, 2604-2606 (2012)

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