All-optical modulation based on the phase-change materials combined with chains of silicon nanoantennas

Chalcogenide phase-change materials are showing promise for the development of non-volatile memory and neuro-inspired computing technologies. One of the key issues in these devices is the energy consumption for the write (crystallization) and erase (amorphization) process. In this work, we propose to combine a PCM with a subwavelength chain of silicon nanoantennas with variable sizes following a parabolic profile. In comparison with a common slab waveguide, it was numerically demonstrated that the nanoparticle chain requires 24 times less energy for the writing and 42 times less energy for erasing process due to slow- light behavior near the photonic band-gap edge, which enhances local electromagnetic fields in the structure. Achieved results could be used for neuromorphic silicon photonics applications.