We report a precision measurement of the parity-violating asymmetry $A_{PV}$ in elastic scattering longitudinally polarized electrons from $^{208}$Pb. measure $A_{PV}=550\pm 16 {\rm (stat)}\pm 8\ (syst)}$ parts per billion, leading to an extraction neutral weak form factor $F_W(Q^2 = 0.00616\ GeV}^2) 0.368 \pm 0.013$. Combined with our previous measurement, extracted neutron skin thickness is $...

In this paper, ultrahigh-Q factor racetrack microring resonators (MRRs) are demonstrated based on silica planar lightwave circuits (PLCs) platform. A loaded Qload of 1.83 × 106 is obtained. The MRRs packaged with fiber-to-fiber loss ~5 dB. notch depth 3 dB and ~137 pm FSR observed. These show great potential in optical communications as filters. Moreover, the devices suitable used monolithic in...

A high-Q-factor tunable silica-based microring resonator (MRR) is demonstrated. To meet the critical-coupling condition, a Mach–Zehnder interferometer (MZI) as coupler was integrated with racetrack resonator. Then, 40 mW electronic power applied on microheater arm of MZI, and maximal notch depth about 13.84 dB loaded Q factor 4.47 × 106 were obtained. The proposed MRR shows great potential in p...