Tolerance of holographic polymer-dispersed liquid crystal memory for gamma-ray irradiation

The radiation-hardened characteristics of holographic polymer-dispersed liquid crystal (HPDLC) memory are discussed in the application for an optically reconfigurable gate array. The radiation experiments are conducted using a cobalt 60 gamma radiation source to examine the tolerance of a 100 Mrad total ionizing dose for the HPDLC memory. The optical properties are compared in the conditions before and after gamma-ray irradiation for the fabricated HPDLC gratings. The effects of gamma-ray irradiation on the internal grating structure are also investigated by polarization optical microscopy and scanning electron microscopy observations. The HPDLC memory irradiated by a 100 Mrad total ionizing dose demonstrates the implementation of the optical reconfiguration in a gate-array VLSI.