Determination of plasma temperature of copper vapour laser

The output power and the temperature profile of a copper vapour laser were investigated versus frequency with various kinds of back mirror in its resonator cavity. A semi-experimental method was used for measuring the plasma temperature and obtaining the temperature profile with various back mirrors. The obtained plasma temperature through this method has good agreement with the operational temperature of the laser. © 2016 Cambridge University Press

Nonlinear buckling analysis of double-layered graphene nanoribbons based on molecular mechanics

Double-layer graphene nanoribbons promise potential application in nanoelectromechanical systems and optoelectronic devices, and knowledge about mechanical stability is a crucial parameter to flourish the application of these materials at the next generation of nanodevices. In this paper, molecular mechanics is utilized to investigate nonlinear buckling behavior, critical buckling stress, and lateral deflection of double-layered graphene nanoribbons under various configurations of stacking mode and chirality. The implicit arc-length iterative method (modified Riks method) with Ramm’s algorithm is utilized to analyze the nonlinear structural stability problem. The covalent bonds are modeled using three-dimensional beam elements in which elastic moduli are calculated based on molecular structural mechanics technique, and the interlayer van der Waals (vdW) interactions are modeled with nonlinear truss elements. An analytical expression for Young’s modulus of nonlinear truss elements is derived based on the Lennard–Jones potential function and implemented in numerical simulation with a UMAT subroutine based on FORTRAN code to capture the nonlinearity of the vdW interactions during the buckling analysis. The results indicate that the highest critical buckling stress and the minimum lateral deflection occur for armchair and zigzag chirality, both with AB stacking mode, respectively. Moreover, the critical buckling stress is found to be directly dependent on the mode shape number regardless of in-phase or anti-phase deflection direction of layers. Lateral deflection exhibits a similar trend with mode shape in anti-phase mode; however, it is decreasing by increasing mode shape number in in-phase mode

Nonlinear optical properties of chalcogenide hybrid inorganic/organic polymers (CHIPs) using the Z-scan technique

The linear and nonlinear optical behavior of novel sulfur based polymer materials are evaluated at the optical communication wavelength, 1550 nm. These polymers are attractive for near-IR (NIR) and mid-IR applications. The two photon absorption (TPA) coefficient (beta) and second order refractive index (n(2)) of chalcogenide hybrid inorganic/organic polymers (CHIPs) from poly(sulfur-random-(1,3-diisopropenylbenzen) (poly(S-r-DIB)) are measured via the Z-scan technique. In this study, we investigated the linear and nonlinear optical behavior of two types of CHIPs where the weight percentage of sulfur is varied (poly(S-50%-r-DIB50%) and poly(S-70%-r-DIB30%)). The TPA coefficients for poly(S-50%-r-DIB50%) and poly(S-70%-r-DIB30%) obtained were 0.11 cm/GW and 0.063 cm/GW, respectively. The n(2) for poly(S-50%-r-DIB50%) and poly(S-70%-r-DIB30%) was measured and determined to be 2.45 x 10(-15) cm(2)/W and 3.06 x 10(-15) cm(2)/W, respectively, and are in good agreement with Miller's rule prediction. These materials exhibit low cost, low temperature processing, high transparency in the near to mid-IR range (except a few interval ranges) and relatively high refractive index, providing a unique set of properties for optics and photonics device applications. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.National Science Foundation (NSF) [DMR-1607971]; Air Force Office of Scientific Research (AFOSR) Phase I & II SBIR contract [FA9550-15-C-0046, FA955017-C4005]; NSF CIAN ERC; Arizona TRIF programOpen access journal.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]