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.

Recent developments in Chalcogenide phase change material-based nanophotonics

“…Typically, their top surface is loaded with individual or arrayed PCM or PCM-metal hybrid nanostructures. Simple waveguides loaded with single nanostructure include [37][38][39][40][41], whereas the arrayed PCM nano-islands or PCM-metal hybrid nanoislands include [42,43]. It was realized that using straightforward configurations achieved a mediocre extinction ratio, high insertion loss, and high switching energies along with limited operation speeds.…”

“…Alternatively, an optimized PCM volume is essential for obtaining high-performance operation. The GST was demonstrated as a switch with high readout contrast (≈33 dB) along with a low insertion loss of 0.79 dB and low power consumption (0.66 mW and 3.71 mW 3.71 mW for switching the memory state from high to low and vice versa respectively) [40]. The authors used a volume of 0.0079 μm 3 of GST 225 resting on a Si waveguide of crosssection 450 nm × 220 nm (width × height) on a 2 μm thick silica substrate (see figure 2(A)).…”

Deep learning aids simultaneous structure–material design discovery: a case study on designing phase change material metasurfaces

“…PCM metasurfaces have been explored in the visible, near-infrared (NIR), and mid-infrared spectra pertaining to a range of applications that are broadly classified into PCM in integrated photonics and metasurfaces. Some examples from the PCM integrated photonics include all-optical multi-level memories, 7 all-optical abacus, 8 all-optical spiking neurosynaptic networks, 9 and non-volatile all-optical switches 10 . PCM metasurface applications include reprogrammable meta-switches, 11 switchable distributed Bragg reflectors, 12 polarization-conversion and filtering, 13 color displays, 14 and beam-switching 15 …”