skip to main content


Search for: All records

Creators/Authors contains: "Gong, Ming"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Thermo-optic phase shifters (TOPSs) are commonly used in large-scale silicon photonic integrated optical phased arrays (OPAs). However, fast-response TOPSs consume relatively high power; the elevated temperature floor in the dense region of the TOPSs introduces thermal crosstalk between optical paths, which undermines the control accuracy. We propose a combined method that involves subarray design in the optical power distribution network and array control method to predict, optimize, and redistribute the phase shifts and mitigates thermal crosstalk. Thermal simulations and an array control method for generic OPA models are discussed. A silicon photonic chip prototype of a 4 × 4 OPA with three-level cascaded subarrays is fabricated to demonstrate the proposed method. The experimental and statistical results show that the method effectively reduces the average total power consumption by 31%, the maximum local temperature by 18.4%, and the thermal crosstalk within the OPA.

     
    more » « less
  2. Abstract

    On a lattice with 2+1-flavor dynamical domain-wall fermions at the physical pion mass, we calculate the decay constants of,, and. The lattice size is, which corresponds to a spatial extension offm, with a lattice spacing offm. For the valence light, strange, and charm quarks, we use overlap fermions at several mass points close to their physical values. Our results at the physical point areMeV,MeV,MeV,MeV, andMeV. The couplings ofandto the tensor current () can be derived from ratiosand, respectively, which are the first lattice quantum chromodynamics (QCD) results. We also obtain ratiosand, which reflect the size of heavy quark symmetry breaking in charmed mesons. Ratiosandcan be taken as a measure ofSU(3) flavor symmetry breaking.

     
    more » « less