Efficient optical reservoir computing for parallel data processing

Abstract

We propose and experimentally demonstrate an optical reservoir computing system in free space, using second-harmonic generation for nonlinear kernel functions and a scattering medium to enhance reservoir nodes interconnection. We test it for one-step and multi-step predication of Mackey–Glass time series with different input-mapping methods on a spatial light modulator. For one-step prediction, we achieve 1.8 × 10−3 normalized mean squared error (NMSE). For the multi-step prediction, we explore two different mapping methods: linear-combination and concatenation, achieving 16-step prediction with NMSE as low as 3.5 × 10−4. Robust and superior for multi-step prediction, our approach and design have potential for parallel data processing tasks such as video prediction, speech translation, and so on.

Observation of Distinct Phase Transitions in a Nonlinear Optical Ising Machine

“…A lens with focal length F = 200mm is used to focus the modulated beam into a temperature-stabilized periodically poled lithium niobate (PPLN) crystal with a poling period of Λ=19.36µm (5mol.% MgO-doped PPLN, length 1cm from HC Photonics). It generates a SH light at λ h ∼ 775.5nm 45 . After passing through another lens of the same focal length, the pump and SH lights are separated by a dichroic mirror (DM) and then coupled into the single mode fibers (SMF-28) using fiber collimators with aspheric lenses Thorlabs C220TMD-C and A375TM-B, respectively, and detected by the power meters (Thorlabs PM-100D with sensors S132C and S130C).…”

Observation of distinct phase transitions in a nonlinear optical Ising machine

“…A lens with focal length F = 200 mm is used to focus the modulated beam into a temperature-stabilized periodically poled lithium niobate (PPLN) crystal with a poling period of Λ = 19.36 μm (5mol.% MgO-doped PPLN, length 1cm from HC Photonics). It generates a SH light at λ h ~775.5 nm 59 . After passing through another lens of the same focal length, the pump and SH lights are separated by a dichroic mirror (DM) and then coupled into the single mode fibers (SMF-28) using fiber collimators with aspheric lenses Thorlabs C220TMD-C and A375TM-B, respectively, and detected by the power meters (Thorlabs PM-100D with sensors S132C and S130C).…”

Observation of Distinct Phase Transitions in a Nonlinear Optical Ising Machine

“…A lens with focal length F = 200mm is used to focus the modulated beam into a temperature-stabilized periodically poled lithium niobate (PPLN) crystal with a poling pe- riod of Λ=19.36µm (5mol.% MgO-doped PPLN, length 1cm from HC Photonics). It generates a SH light at λ h ∼ 775.5nm [45]. After passing through another lens of the same focal length, the pump and SH lights are separated by a dichroic mirror (DM) and then coupled into the single mode fibers (SMF-28) using fiber collimators with aspheric lenses Thorlabs C220TMD-C and A375TM-B, respectively, and detected by the power meters (Thorlabs PM-100D with sensors S132C and S130C).…”