Silicon coding-decoding photonic device by electron irradiation and light down conversion

摘要

We propose and demonstrate a coding-decoding procedure as an important step to realize one more Si-based photonic device. Low-fluence (<1014 e/cm2) high-energy (1 MeV) electron irradiation of a bulk Si matrix is used to code an information by forming local regions with lower free carrier lifetime that are hidden under the surface and invisible to the eye. Short-wavelength (<1 μm) free carrier generation stands for multiple, remote, and nondestructive decoding process, which makes it easy to dynamically (ms range) visualize a code by capturing two-dimensional pattern of thermal emission in the longer-wavelength (3–12 μm) band (light down conversion).