Compact multi-mode silicon-nitride micro-ring resonator with low loss

The article comments on a new way to design multiple microring resonators with large free spectral range and high intrinsic Q-factor, within the standard manufacturing process

Modelling Brillouin activated microcombs in multi-layered silicon nitride waveguides

We investigate a numerical model to simulate the optical frequency comb generation in Kerr and Brillouin active resonators with gain parameters in the same order of magnitude. We show that either a backward or forward comb can be generated directly on a Brillouin laser or a cascaded Brillouin lasing mode respectively for a multi-layered silicon nitride waveguide structure

Ultra-Efficient On-Chip Supercontinuum Generation from Sign-Alternating-Dispersion Waveguides

Fully integrated supercontinuum sources on-chip are critical to enabling applications such as portable and mechanically-stable medical imaging devices, chemical sensing and LiDAR. However, the low-efficiency of current supercontinuum generation schemes prevent full on-chip integration. In this letter, we present a scheme where the input energy requirements for integrated supercontinuum generation is drastically lowered by orders of magnitude, for bandwidth generation of the order of 500 to 1000 nm. Through sign-alternating the dispersion in a CMOS compatible silicon nitride waveguide, we achieve an efficiency enhancement by factors reaching 3800. We show that the pulse energy requirement for large bandwidth supercontinuum generation at high spectral energy (e.g., 1/e level) is lowered from nanojoules to 6 picojoules. The lowered pulse energy requirements enables that chip-integrated laser sources, such as mode-locked heterogeneously or hybrid integrated diode lasers, can be used as a pump source, enabling fully integrated on-chip high-bandwidth supercontinuum sources

Linearized integrated microwave photonic circuit for filtering and phase shifting

Photonic integration, advanced functionality, reconfigurability, and high radio frequency (RF) performance are key features in integrated microwave photonic systems that are still difficult to achieve simultaneously. In this work, we demonstrate an integrated microwave photonic circuit that can be reconfigured for two distinct RF functions, namely, a tunable notch filter and a phase shifter. We achieved &gt; 50 dB high-extinction notch filtering over 6-16 GHz and 2π continuously tunable phase shifting over 12-20 GHz frequencies. At the same time, we implemented an on-chip linearization technique to achieve a spurious-free dynamic range of more than 120 dB · Hz 4/5 for both functions. Our work combines multi-functionality and linearization in one photonic integrated circuit and paves the way to reconfigurable RF photonic front-ends with very high performance.</p

Surface acoustic wave stimulated Brillouin scattering in thin-film lithium niobate waveguides

We report the first-ever experimental observation of backward stimulated Brillouin scattering (SBS) in thin-film lithium niobate (TFLN) waveguides. The peak Brillouin gain coefficient of the z-cut LN waveguide with a crystal rotation angle of 20$^{\circ}$ is as high as 84.9m$^{-1}$W$^{-1}$, facilitated by surface acoustic waves (SAW) at 8.06GHz