Letters in 2009

Using a single layer of electrically controlled metamaterial, researchers have achieved active control of the phase of terahertz waves and demonstrated high-speed broadband modulation.

A system based on a highly nonlinear planar chalcogenide waveguide is demonstrated to be able to perform radio-frequency spectral measurements with a terahertz bandwidth. High bit-rate tests show that the chip-based system is potentially useful for ultrafast signal processing.

By using an optical frequency comb as the light source for Fourier transform spectroscopy, scientists show that well-resolved broadband absorption and dispersion spectra can be recorded in a single experiment, providing sensitive detection of multiple molecular species over a broad spectral window.

The tiny phase changes introduced by nonlinear optics performed at the single-photon level is reported in a photonic crystal fibre with carefully designed nonlinear and dispersion properties. The approach may prove useful in future quantum information processing schemes.

The realization of a chip-based, broadband optical isolator is of considerable interest for integrated photonics. To date, no technique has been shown to be able to do this using materials and processes that are CMOS-compatible. Now, scientists propose that the use of direction-dependent photonic mode transitions in silicon nanophotonic structures could be the solution.