Reviews & Analysis

High-precision synchronization of remote timing sources is an increasing problem for large-area facilities, such as radio telescope arrays and particle accelerators. Femtosecond-pulse-train transfer by optical fibre may represent a solution.

Ultrashort laser pulses now make it possible to fabricate a wide range of biomaterials and implants ranging from cell scaffolds to artificial microvalves.

The dynamics of chaotic lasers can be harnessed to create a random-number generator that works at an astonishing rate. Such a generator could be implemented to make storage and transfer of data more secure at very high speeds.

By using laser frequency combs to stabilize astronomical spectrometers, it may be possible to better understand our expanding Universe.

Coupled optical microresonators are one way of slowing down light. A new record has now been set for the length of these slow-light waveguides using an array of more than 100 photonic-crystal cavities.

The effect of spin on the trajectories of polarized light beams has now been experimentally observed, with results that agree with the predictions of Berry phase theory.

The word 'ceramics' is derived from the Greek keramos, meaning pottery and porcelain. The opaque and translucent cement and clay often used in tableware are not appropriate for optical applications because of the high content of optical scattering sources, that is, defects. Recently, scientists have shown that by eliminating the defects, a new, refined ceramic material — polycrystalline ceramic — can be produced. This advanced ceramic material offers practical laser generation and is anticipated to be a highly attractive alternative to conventional glass and single-crystal laser technologies in the future. Here we review the history of the development of ceramic lasers, the principle of laser generation based on this material, some typical results achieved with ceramic lasers so far, and discuss the potential future outlook for the field.

Researchers have demonstrated the first photonic-crystal system with light emitters that experience three-dimensional photonic and electronic confinement.

By introducing a radial chirp in the dimension of the cells surrounding the central core, researchers now demonstrate a low-dispersion photonic-crystal fibre that could overcome the long-standing problem of ultrashort-pulse delivery.

A bifacial dye-sensitized solar cell that can efficiently generate electricity when illuminated from either side may help bring down the cost of solar energy production.

The ability of Airy light beams to transport microparticles along curved, self-healed paths may lead to useful applications in biology and colloidal science.

Focusing ultrashort red and blue laser pulses into a gas generates terahertz pulses with unprecedented pulse energies. Such pulses enable nonlinear terahertz spectroscopy and the time-resolved study of field-induced effects.

The photonics applications of engineered liquid crystals extend far beyond their use in displays. High-density optical data storage, tunable lasers and metamaterials are just a few of the other opportunities.

Researchers demonstrate fast optical focusing using an oscillating liquid lens. The method could lead to the development of three-dimensional imaging instruments with rapid data collection.

Diode-pumped thin-disk lasers are now capable of generating femtosecond light pulses with a pulse energy in the microjoule regime at multi-megahertz repetition rates. This review describes the progress that has been made in scaling the performance of such lasers and the applications that may benefit as a result.