Optics and photonics technologies are at work improving our
lives in many ways.
These technologies are what provide sustainable lighting
and energy-generation systems. Nanoparticles are used to rapidly diagnose disease or derive
3D images of living, functioning cells. Optical resonators detect counterfeit
or pirated goods. Airborne telescopes probe deep into the Universe while
optical fibers send messages instantly across the globe.
Engineers and scientists from around the world meet every
August at SPIE Optics + Photonics in San Diego to advance research in several
broad areas of optics and photonics. A few of the 3,000+ researchers who will
present reports next week have provided previews via articles they have
authored recently for the SPIE Newsroom.
Recent epidemic outbreaks have highlighted the need for a
rapid point-of-care assay that can provide a diagnosis to enable treatment,
proper quarantining, and disease surveillance. One promising diagnostic is the
lateral flow test, i.e., the same type of assay used in pregnancy tests: a
paper strip to which a biological fluid is added. These are attractive for diagnostics
because they are inexpensive, easy to use, and do not require special reagents
or experts to run them.
Cargo logistics — driven by cytoskeletal motors and
proceeding along actin and microtubule filaments — are an essential subsystem
of the overall machinery of eukaryotic cells. It is no stretch to say that
virtually every process in a living cell depends, directly or indirectly, on
proper routing of cargoes in a timely fashion. Much progress has been made in
the last few decades in understanding the structure and properties of
individual filaments and motors, but clean experimental modeling of how these
components add up to a functional cytoskeleton still poses many challenges.
The prevalence of counterfeited and pirated goods in
modern society has increased the demand for anticounterfeiting technologies. Global
trade of such items in 2015 was estimated to be worth $960 billion, and a danger
to 2.5 million jobs. Much effort has been made in the development of smart
security labels designed to hide information in normal conditions and reveal it
in others.
An LED with an emissive organic thin film sandwiched
between the anode and cathode is known as an organic-LED (OLED). The emission
mechanism of an OLED is superficially similar to that of a standard LED, i.e.,
holes and electrons are injected from the anode and cathode, respectively, and
these carriers recombine to form excited states (excitons) that lead to light
emission. In recent years, smartphones and TVs with OLED displays have rapidly
become widespread because OLEDs provide high contrast, a wide color gamut,
light weight, thinness, and flexibility for the displays. OLEDs also have great
potential for the creation of new lighting applications. The high power
consumption and short lifetime of OLEDs, however, remain key issues.
Non-centrosymmetric crystals whose optical response does
not vary linearly with the strength of an electric field — known as nonlinear
optical (NLO) crystals — are the fundamental building blocks for most
electro-optic applications. The production of novel NLO crystals is very
difficult because it entails bulk techniques that require long growth times and
expensive equipment, and that often result in low-quality crystals. For more
than three decades, lasers have been used to make modifications to glass
refractive indices in the fabrication of high-efficiency waveguides. In recent
work, the use of femtosecond laser sources facilitates the fabrication of
multidimensional structures composed of many types of NLO crystals.
Computerized axial tomography scanning has revolutionized
medical imaging, and through microtomography, its spatial resolution can be
reduced from the millimeter scale to the micrometer scale. Microtomography has
developed rapidly, driven by developments in x-ray sources, computers, and
particularly in detectors. There are now microtomography systems available for
laboratory use and microtomography has been applied to fields including
biology, geology, soil science, and the study of meteorites. Monochromatic
beams are generally unsuitable for dynamic studies. So-called pink beam microtomography
is an alternative.
Large parts of the IR spectrum are inaccessible in
observations made from ground-based telescopes because of absorption by water
vapor in the atmosphere.For
this reason, the Stratospheric Observatory for IR Astronomy (SOFIA) — a joint
project between NASA and the German Aerospace Center (DLR) — was designed and
has been operational since 2010. SOFIA has become a key facility for several
astronomy investigations, e.g., for studying regions of star formation,
observing objects obscured by interstellar dust, and making time-critical
measurements of transient events.
Quantum key distribution (QKD) is of much interest for
quantum communications because of its high level of privacy (underpinned by
quantum mechanics). In particular, entanglement-based QKD is a powerful
technique in which quantum correlations between photons are leveraged. In this
process, the entangled photons can be distributed with the use of optical
fibers or ground-level free-space links. Current QKD networks, however, suffer
from a distance limit because of fiber losses and the lack of quantum
repeaters.
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