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Stochastic mesoscale inhomogeneity of material properties and material symmetries are investigated in a 3D-printed material. The analysis involves a spatially-dependent characterization of the microstructure in 316 L stainless steel, obtained through electron backscatter diffraction imaging. These data are subsequently fed into a Voigt–Reuss–Hill homogenization approxima- tion to produce maps of elasticity tensor coefficients along the path of experimental probing. Information-theoretic stochastic models corresponding to this stiffness random field are then introduced. The case of orthotropic fields is first defined as a high-fidelity model, the realizations of which are consistent with the elasticity maps. To investigate the role of material symmetries, an isotropic approximation is next introduced through ad-hoc projections (using various metrics). Both stochastic representations are identified using the dataset. In particular, the correlation length along the characterization path is identified using a maximum likelihood estimator. Uncertainty propagation is finally performed on a complex geometry, using a Monte Carlo analysis. It is shown that mechanical predictions in the linear elastic regime are mostly sensitive to material symmetry but weakly depend on the spatial correlation length in the considered propagation scenario. 

This talk reviews photonic integrated circuit materials, devices and integration techniques developed at MIT Lincoln Laboratory to support the needs of next generation quantum systems across the wavelength spectrum from the near-ultraviolet to the midwave-infrared. 

We design and experimentally demonstrate the first pair of integrated TE- and TM- emitting gratings at a wavelength of 422nm, targeting the 5²s_1/2-5²p_1/2transition of⁸⁸Sr⁺ions, to enable operations requiring diverse polarizations for integrated-photonics-based trapped-ion quantum systems. 

We develop a framework for two advanced trapped-ion cooling schemes, polarization-gradient and electromagnetically-induced-transparency cooling, for⁸⁸Sr⁺ions using a visible-wavelength integrated-photonics platform and present the design of the key integrated devices.