# Photonic Matrix-Vector Multiplication

A silicon-photonic matrix-vector multiplication engine is designed around mode-division multiplexing, using the fundamental and first-order transverse magnetic modes as two parallel computing channels and weighting signals through the amorphous-to-crystalline contrast of a Ge2Sb2Se4Te1 phase-change material. Weights persist without static power, the 2×2 optical core measures 185 µm × 21 µm, and total insertion loss at 1550 nm is 2.76 dB for TM0 and 3.64 dB for TM1 across a 40 nm band from 1540 to 1580 nm. All results come from optical and electro-thermal numerical simulation and have not been experimentally validated.

A silicon-photonic matrix-vector multiplication engine is designed around mode-division multiplexing, using the fundamental and first-order transverse magnetic modes as two parallel computing channels and weighting signals through the amorphous-to-crystalline contrast of a Ge2Sb2Se4Te1 phase-change material. Weights persist without static power, the 2×2 optical core measures 185 µm × 21 µm, and total insertion loss at 1550 nm is 2.76 dB for TM0 and 3.64 dB for TM1 across a 40 nm band from 1540 to 1580 nm. All results come from optical and electro-thermal numerical simulation and have not been experimentally validated.