96 research outputs found
Notes on Evanescent Wave Bragg-Reflection Waveguides
We investigate an extended version of the Bragg reflection waveguide (BRW)
with air gaps as one of the layers. This design has the potential of
drastically simplifying the epitaxial structure for integrated nonlinear
optical elements at the expense of more complicated structuring. This approach
would afford much more flexibility for designing and varying BRW structures.
Here, we discuss an extension of the established theory for BRW slabs and
report our results of applying Marcatili's method for rectangular waveguides to
the BRW case. With this analytic approach we can estimate the effective index
of the modes orders of magnitudes faster than with full numerical techniques
such as finite-difference time-domain (FDTD) or finite elements. Initial
results are mixed; while phase-matched designs have been found, they currently
have no significant advantage over other schemes.Comment: 5 pages, 2 figure
Photonic Entanglement for Fundamental Tests and Quantum Communication
Entanglement is at the heart of fundamental tests of quantum mechanics like
tests of Bell-inequalities and, as discovered lately, of quantum computation
and communication. Their technological advance made entangled photons play an
outstanding role in entanglement physics. We give a generalized concept of
qubit entanglement and review the state of the art of photonic experiments.Comment: 54 pages, 33 figures. Review article submitted to QIC (Rinton
Parametric down-conversion in photonic crystal waveguides
Photonic crystals create dramatic new possibilities for nonlinear optics.
Line defects are shown to support modes suitable for the production of pairs of
photons by the material's second order nonlinearity even if the phase-matching
conditions cannot be satisfied in the bulk. These structures offer the
flexibility to achieve specific dispersion characteristics and potentially very
high brightness. In this work, two phase matching schemes are identified and
analyzed regarding their dispersive properties.Comment: Due to a miscommunication the unrevised version of this paper was
published instead of this one. v2 has quite some modifications and
corrections. 7 pages, 4 figure
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