Sandia Labs FY22 Laboratory Directed Research & Development Annual Report

Journal Covers

“Inelastic Relaxation in Silica Via Reactive Molecular Dynamics,” published in the Journal of the American Ceramic Society (April 2022), uses molecular dynamics simulations to explore how silica glass behaves under deformation. The work is part of the LDRD

“Analysis of the Spontaneous Emission Limited Linewidth of an Integrated III–V/SiN Laser,” published in Laser & Photonics Reviews (June 2022), develops a new approach to

reduce the linewidth of a semiconductor laser coupled to a

“Stress Intensity Thresholds for Development of Reliable Brittle Materials” led by PI Jessica Rimsza that investigates the conditions that govern when, or if, a material will fail. The cover images illustrate stress distributions at the atomic scale ahead of a crack tip following relaxation at varying temperatures.

silicon nitride resonator, including potential improvements to optimize device engineering. The work is part of the LDRD “High Performance Heterogeneously Integrated Lasers for RF Photonics and Quantum Sensing” led by PI Michael Gehl that explores the materials, fabrication processes, and physics required to demonstrate

a fully heterogeneously integrated laser (<100Hz linewidth, relative intensity noise below -165 DBc/Hz).

“Semi-Automated, Object-Based Tomography of

“Observation of Quadratic (Charge-2) Weyl Point Splitting in Near-Infrared Photonic Crystals,” published in Laser and Photonics Reviews (January 2022), experimentally demonstrates (using infrared spectroscopy) splitting of a quadratic

Dislocation Structures,” published in Microscopy and Microanalysis (June 2022), presents a new method of studying dislocations in materials sciences that reduces the amount of data needed

by using prior knowledge of dislocations being line objects. The work is part of the LDRD “Dislocation Cell-Wall Formation in Deformed Structural Metals: Untangling the Theory of Low Energy Dislocation Structures” led by PI Douglas Medlin that investigates the mechanisms governing the formation and stability of dislocation cell walls in minerals. The cover image depicts a raw diffraction-contrast scanning transmission electron microscope image of dislocations.

Weyl point into two linear Weyl points on a photon crystal, which gives insight into creating topological devices that work in the near infrared. The work is part of the LDRD “Enhancing Photonic Systems Using Topology and Non-Hermiticity” led by PI Alex Cerjan that is discovering new methods and mechanisms for confining light in compact photonic structures using recent discoveries in the fields of topological and non-Hermitian physics.

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LABORATORY DIRECTED RESEARCH & DEVELOPMENT