Volume 12 Issue 10, October 2018

An acoustic wave can induce non-reciprocal light modulation in a silicon waveguide. Now, the acoustic wave has been induced optically in a neighbouring silicon waveguide, opening the way for a silicon-based optical isolator.

Artificial intelligence looks poised to drive the development of software and hardware platforms in the coming decades. In photonics, it is already proving invaluable and is having an impact in the areas of imaging, sensing and communications.

The achievement of plasmonic-enhanced silicon-based terahertz emitters and detectors brings hope for the realization of integrated circuits that bring together electronics, photonics and terahertz functions on a single chip.

The first three-dimensional nonlinear photonic crystals have been constructed thanks to the use of femtosecond laser writing in quadratic nonlinear materials.

Over the past 10–15 years, quantitative phase imaging has moved from a research-driven to an application-focused field. This Review presents the main principles of operation and representative basic and clinical science applications.

A three-dimensional nonlinear photonic crystal in ferroelectric barium calcium titanate that enables phase matching of nonlinear processes along an arbitrary direction, thereby removing constraints imposed by low-dimensional structures, is experimentally realized.

By selectively erasing the nonlinear coefficients in a lithium niobate crystal using a femtosecond laser, a 3D nonlinear photonic crystal, with an effective conversion efficiency comparable to that of the typical quasi-phase-matching processes, is demonstrated.

Black phosphorus/molybdenum disulfide mid-wave infrared photodiodes with external quantum efficiencies of 35% across 2.5–3.5 μm at room temperature and a peak detectivity of 1.1 × 10¹⁰ cm Hz^1/2 W^–1 at 3.8 μm are demonstrated.

Terahertz (THz) spectroscopy based on a single-molecule transistor detects a THz-induced centre-of-mass oscillation of a fullerene molecule. Its sensitivity is so high that the spectrum changes on adding (removing) an electron to (from) the molecule.

Non-reciprocal single-sideband modulation and mode conversion are realized in a low-loss integrated silicon waveguide, enabling >125 GHz operation bandwidths and up to 38 dB of non-reciprocal contrast between forward- and backward-propagating waves.

Coherent extreme-ultraviolet emission through frustrated tunnelling ionization is observed from He atoms excited by intense few-cycle infrared laser pulses. Its intensity depends on the ellipticity and the carrier-envelope phase of the infrared laser.

Transmitters and receivers based on plasmonic internal-photoemission detectors are developed for optoelectronic terahertz signal processing and monolithically integrated on a silicon chip. Proof-of-concept experiments are demonstrated.