Biomedical Engineering Reference
In-Depth Information
arrays is relevant to a number of applications in singular optics,
classical, and quantum cryptography.
11.1 Introduction to Aperiodic Optical Structures
Periodic optical media support extended Bloch eigenmodes and
featurecontinuousenergybands[1].Onthecontrary,intheabsence
of inelastic interactions, random media can feature exponentially
localized eigenmodes and energy spectra characterized by isolated
δ
-peaks [2]. A substantial amount of work has been devoted
in the past few years to understand transport, localization, and
wave scattering phenomena in disordered random media [2-
6]. These activities unveiled fascinating analogies between the
behavior of electronic and optical waves, such as disorder-induced
Andersonlightlocalization[6,7],thephotonicHalleffect[8],optical
magnetoresistance [9], universal conductance fluctuations of light
waves [10], and optical negative temperature coe
cient resistance
[11]. However, the engineering of light scattering and transport
phenomena in complex optical systems, such as random media, is
stillverylimited.Infact,randomstructures,whileprovidingaconve-
nient path to field localization, are not reproducible and lack simple
engineering design rules for deterministic optimization. These
di
culties have strongly limited our ability to conceive, explore,
and manipulate optical resonances and light scattering phenomena
in systems devoid of spatial periodicity. On the contrary, aperiodic
optical media generated by deterministic mathematical rules,
knownasdeterministicaperiodicstructures,haverecentlyattracted
significant attention in the optics and electronics communities due
to their simplicity of design, fabrication, and compatibility with
current materials deposition and device fabrication technologies
[12-16]. Initial work, mostly confined to theoretical investigations
of one-dimensional (1D) aperiodic systems [17-24], have fully
succeeded in stimulating broader experimental/theoretical studies
of optical nanostructures that leverage deterministic aperiodic
order as a comprehensive strategy for the design and manipulation
of optical modes and frequency spectra to achieve new device
functionalities. In addition to the numerous applications to optical
