SiN integrated optical phased arrays for two-dimensional beam steering at a single near-infrared wavelength.

In this work, we present two-dimensional beam steering in the near-infrared using a SiN integrated circuit, containing optical phased arrays. Beam steering was achieved over a range of 17.6° × 3°, at a fixed wavelength of 905 nm. The first dimension was steered via phase differences between the optical phased array channels. The second dimension was accessed by actively switching between various optical phased array sub-devices containing output diffraction gratings with different periods. The characterisation was performed on a wafer-level test station.

Anomalous temperature dependence of the dephasing time in mesoscopic kondo wires.

We present measurements of the magnetoconductance of long and narrow quasi-one-dimensional gold wires containing magnetic iron impurities in a temperature range extending from 15 mK to 4.2 K. The dephasing rate extracted from the weak antilocalization shows a pronounced plateau in a temperature region of 300-800 mK, associated with the phase breaking due to the Kondo effect. Below the Kondo temperature, the dephasing rate decreases linearly with temperature, in contradiction with standard Fermi-liquid theory. Our data suggest that the formation of a spin glass due to the interactions between the magnetic moments is responsible for the observed anomalous temperature dependence.