Title

Phase Change Dynamics and Two-Dimensional 4-Bit Memory in Ge2Sb2Te5 via Telecom-Band Encoding

Document Type

Article

Publication Date

2-19-2020

Publication Source

ACS Photonics

Abstract

We propose and demonstrate a two-dimensional 4-bit fully optical nonvolatile memory using Ge2Sb2Te5 (GST) phase change materials, with encoding via a 1550 nm laser. Using the telecom-band laser, we are able to reach deeper into the material due to the low-loss nature of GST at this wavelength range, hence, increasing the number of optical write/read levels compared to previous demonstrations, while simultaneously staying within acceptable read/write energies (maximum 60 nJ/bit for write, depending on the number of pulses). For our experimental results, 50 ns long pulses with a 25 ns fall time, a peak power of 200 mW, and a 125 kHz repetition rate were used. We verify our design and experimental results via rigorous numerical simulations based on finite element and nucleation theory, and we successfully write and read a string of characters using direct hexadecimal encoding.

Inclusive pages

480-487

ISBN/ISSN

2330-4022

Publisher

ACS Publications

Volume

7

Issue

2

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