Fig. 1

Optical vector matrix multipliers. a Vector matrix multiplier based on spatially separated devices. A_i, B_{i, j} and C_i represent input data, matrix element and computing result, respectively. b SVD decomposition. Here, V, Σ and U represent a unitary matrix, a diagonal matrix and a unitary matrix, respectively. Each unitary matrix can be uploaded into either Clement’s structure or Reck’s structure. c Scheme of VMM chip based on wavelength division multiplexing and micro-ring array. A_i, B_{i, j} and C_i represent input data, matrix element and computing result, respectively. d ‘Cross-bar’ scheme of VMM implemented by on-chip micro-comb and PCM modulator matrix. A_i, B_{i, j} and C_i represent input data, matrix element and computing result, respectively