2019/10/07 by Gary A. Sevison, Shiva Farzinazar, Sevison, Gary A. +20
Engineering · Materials Science · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Nonlinear Optical Materials Studies #Optics (physics.optics) #Phase-change materials and chalcogenides #Photonic and Optical Devices
paper · pdf · doi:10.48550/arxiv.1911.03536
openalex publication_date 2019/10/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
As modern computing gets continuously pushed up against the von Neumann\nBottleneck -- limiting the ultimate speeds for data transfer and computation --\nnew computing methods are needed in order to bypass this issue and keep our\ncomputer's evolution moving forward, such as hybrid computing with an optical\nco-processor, all-optical computing, or photonic neuromorphic computing. In any\nof these protocols, we require an optical memory: either a\nmultilevel/accumulator memory, or a computational memory. Here, we propose and\ndemonstrate a 2-dimensional 4-bit fully optical non-volatile memory using\nGe2Sb2Te5 (GST) phase change materials, with encoding via a 1550 nm laser.\nUsing the telecom-band laser, we are able to reach deeper into the material due\nto the low-loss nature of GST at this wavelength range, hence increasing the\nnumber of optical write/read levels compared to previous demonstrations, while\nsimultaneously staying within acceptable read/write energies. We verify our\ndesign and experimental results via rigorous numerical simulations based on\nfinite element and nucleation theory, and we successfully write and read a\nstring of characters using direct hexadecimal encoding.\n