Optical sensors

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The photonic sensors market is a diverse and fragmented one. David Krohn, chair of the Optoelectronics Industry Development Association's Photonic Sensor Consortium, tells Nadya Anscombe that the difference between success and failure often depends on understanding your market.

Time-domain cavity solitons could be a promising candidate for creating all-optical buffers integrated with pulse reshapers and wavelength converters. Stéphane Coen spoke with Nature Photonics about the generation of these solitons and their potential applications in telecommunications.

The increasing capability for manufacturing a wide variety of optoelectronic devices from polymer and polymer–silicon hybrids, including transmission fibre, modulators, detectors and light sources, suggests that organic photonics has a promising future in communications and other applications.

Using a composite photonic-crystal structure composed of both a square and rectangular lattice, scientists successfully realize an on-chip semiconductor laser whose emitted beams can be dynamically controlled by varying their relative lattice constants.

Water condensation from air using intense, ultrashort laser pulses is demonstrated, an approach that could benefit remote sensing and studies in atmospheric science.

Long-range surface plasmon propagation with net positive gain over macroscopic distances is directly observed. The gain is provided by an optically pumped layer of fluorescent conjugated polymer that is adjacent to the metal waveguide surface.

Scientists demonstrate a simple self-referenced feed-forward approach for stabilizing the carrier–envelope phase of femtosecond light pulses. Twelve attoseconds of residual timing jitter below the atomic unit of time is achieved, surpassing the precision of previous methods by more than a factor of five.

Microscale planar optical elements based on high-reflectivity, non-periodic gratings provide a compact and convenient means for focusing and shaping light.

Using standard silica optical fibres, scientists observe temporal cavity solitons — packets of light persisting in a continuously driven nonlinear resonator. Cavity solitons 4 ps long are reported and used to demonstrate storage of a data stream for more than a second. The findings represent one of the simplest examples of self-organization phenomena in nonlinear optics.

All-optical switching energies as small as 0.42 fJ — two orders of magnitude lower than previously reported — are demonstrated in small photonic crystal cavities incorporating InGaAsP. These devices can switch within a few tens of picoseconds, and may therefore have potential for low-power high-density all-optical processing on a chip.

A recording density of 1.5 Pb m⁻² using heat-assisted magnetic recording in a bit-patterned media is demonstrated. This represents a dramatic improvement in track width and optical efficiency over continuous media, owing largely to advantageous near-field optical effects.

Frequency combs are created by stabilizing the evolution of the carrier–envelope phase of a mode-locked laser. Researchers have now demonstrated a simplified method of creating frequency combs that enables trains of identical pulses to be easily produced.

A composite photonic crystal that allows on-chip control over the emission direction of a semiconductor laser diode looks set to benefit mobile projection displays, lasers printers and chip-to-chip optical communication.

High-performance, ultracompact lenses are needed in the quest to miniaturize optical systems. It now seems that carefully engineered subwavelength gratings can function as almost perfect mirrors with custom-designed focusing properties.

Packets of light persisting in a continuously driven nonlinear resonator in the time domain offer new possibilities not only for applications in all-optical storage, pulse reshaping and wavelength conversion, but also for fundamental experiments in nonlinear science.

A new gating scheme based on polarization control and second-harmonic generation is greatly simplifying the production of isolated attosecond pulses.

Europe has always been a hub of innovation for photonics, and this year's Photonics Europe conference has shown that young inventors are still coming up with great ideas for commercialization.

Developing new sensor technology requires knowledge from every area of science and engineering. Nadya Anscombe finds out how this is done at the National Centre for Sensor Research in Ireland.

A high-definition LIDAR system with a rotating sensor head containing 64 semiconductor lasers allows the efficient generation of 3D environment maps at unprecedented levels of detail.

Distributed fibre-optic sensors that rely on Brillouin scattering are being used by the oil and gas industries to keep their infrastructure safe and working properly.

A direct UV writing technique that can create multiple Bragg gratings and waveguides in a planar silica-on-silicon chip is enabling sensing applications ranging from individual disposable sensors for biotechnology through to multiplexed sensor networks in pharmaceutical manufacturing.