ITEE seminar: Dr Marian Majewski, 02.00PM, Tue 29 Jul 2003

Photonic Crystals and their applications to microwave and photonic devices

Speaker: Dr Marian Majewski, ITEE

When: 02.00PM, Tuesday 29 Jul 2003

Venue: 78-622

Host: Dr Marian Majewski

Abstract:

  Photonic Crystals (PCs) are periodic structures and there are
  natural examples already existing in nature which reflect
  electromagnetic radiation as propagation through them is selectively
  prohibited. Semiprecious opals and wings of some tropical
  butterflies known for their brilliantly rich colours are just only
  two examples of natural photonic crystals. Present work on
  artificial PCs concentrates on copying these unique properties found
  in nature to use them to develop novel photonic and microwave
  devices.

  The action of repulsion/reflection of electromagnetic waves,
  whatever the frequency at which it occurs is due to the fabric of
  the crystal. The periodicity and the fill factor of the crystal are
  important characteristics to the formation of the desired bad gap.

  In principle, the PC operation relies on producing the optical
  equivalent of the 'forbidden energy band-gap' to the well known
  electronic bad-gap in the electronic structure of semiconductor
  crystals. The electronic band-gap excludes electrons of certain
  energies - an essential feature of many semiconductor devices
  ranging from transistors to lasers. This property of PCs enables one
  to fully control light (electromagnetic waves) propagation in any
  direction and at the desired wavelength range. The light in PCs
  travels in a form of Bloch waves that are similar to ordinary plane
  waves in continuous crystals, and because of the scalability of this
  property of PCs they can also be used at microwave/millimetre wave
  frequencies for integrated circuits and antennas, for example.

  First artificial PCs (or Photonic Band-Gap (PBG) materials) were
  proposed about a decade ago by Sajeev John (Univ. of Toronto), and
  Eli Yablonovitch (UCLA).

  The seminar will start with a brief outline of some important
  similarities between the quantum mechanical (periodic potential) and
  electromagnetic (periodic dielectric) analytical treatment of the
  solid-state matter. Then the three basic PC structures namely; 1-D,
  2-D, and 3-D and their fundamental properties will be
  discussed. Subsequently, several practical microwave (planar
  antenna), and photonic devices (waveguides, couplers, single-mode
  laser, and a super-prism) using PCs will be presented. In this part
  a brief discussion on the recent commercial availability of the PC
  based optical fibres will be included.

  In addition, some basic characterization methods that are applicable
  to PC devices at both microwave and optical frequencies will be
  presented.

  Finally, comments on the leading research group in this area
  worldwide will conclude the seminar.

Biography:

  Speaker biography see  http://www.itee.uq.edu.au/~mpsg/

Contact:

Dr Marian Majewski, seminar host (mjm@itee.uq.edu.au)
or Guido Governatori (ITEE seminar co-ordinator) (guido@itee.uq.edu.au)

ITEE seminar web page: http://www.itee.uq.edu.au/~seminar

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