We overcome this drawback and demonstrate a successful induction of χ(2) in Si3N4 through electrical poling with an externally-applied field to align the Si-N bonds. This alignment breaks the centrosymmetry of Si3N4, and enables the bulk χ(2). The sample is heated to over 500°C to facilitate the poling. The comparison between the EO responses of poled and non-poled Si3N4, measured using a Si3N4 micro-ring modulator, shows an enhancement in the amplitude of the measured EO responses as well as a remarkable improvement in its speed from 3GHz to at least 15GHz (3dB bandwidth) after the poling, which confirms the χ(2) nature of the EO response induced by poling.

Changing the frequency of light outside the laser cavity is essential for an integrated photonics platform, especially when the optical frequency of the on-chip light source is fixed or challenging to be tuned precisely. To achieve continuous on-chip optical frequency[...]

We develop an intelligent algorithm to detect monolayers of WSe2, MoS2 and h-BN autonomously using Digital Image Processing and Deep Learning with high accuracy rate, avoiding human interaction and any additional characterization tests.

Weak value amplification is a technique that allows interferometric signal enhancement without amplifying technical noises. We implement weak value amplification on an integrated Mach-Zehnder interferometer by spatial and temporal phase engineering of the optical wave in waveguides. We achieve 7 dB signal-to-noise ratio improvement over standard integrated Mach-Zehnder interferometer (equal detected optical power) in a heat-induced phase shift measurement. Also, by adding ring resonator to the weak value interferometer as dispersive element, we detect an optical frequency shift down to 2 kHz.