Active volume engineered waveguide embedded nonvolatile photonic memory cell

Abstract

We report thorough investigations of a photonic memory with phase change material embedded in a partially etched silicon waveguide, for operation at 1550 nm wavelength. Optical and thermal analyses are performed to study the performance of memory and the effect of deformity in G e 2 S b 2 T e 5 (GST) cells due to volume contraction upon crystallization. The presented approach has better performance than other approaches with GST integrated on top of or filled in a fully etched waveguide. It is shown that a high readout contrast of ∼ 33 d B with a low insertion loss of 0.79 dB is possible using an active volume of only 0.0079 µ m 3 . The photonic memory presented shows a low power consumption of 0.66 mW and 3.71 mW for switching the memory state from high to low and vice versa, respectively, with zero static power consumption. Using 100 ns and 10 ns pulses for phase transformation from amorphous to crystalline and that from crystalline to amorphous, the energy consumption is 82 pJ and 44.1 pJ, respectively.