All-Optical Reinforcement Learning In Solitonic X-Junctions

Abstract

Ethology has shown that animal groups or colonies can perform complex calculation distributing simple decision-making processes to the group members. For example ant colonies can optimize the trajectories towards the food by performing both a reinforcement (or a cancellation) of the pheromone traces and a switch from one path to another with stronger pheromone. Such ant’s processes can be implemented in a photonic hardware to reproduce stigmergic signal processing. We present innovative, completely integrated X-junctions realized using solitonic waveguides which can provide both ant’s decision-making processes. The proposed X-junctions can switch from symmetric (50/50) to asymmetric behaviors (80/20) using optical feedbacks, vanishing unused output channels or reinforcing the used ones.

Solitonic waveguide reflection at an electric interface

“…Spatial soliton formation, propagation, reflection and breathing through a dynamically induced electro-optic interface in the bulk of a nonlinear material is simulated with a robust, custom, FDTD code whose results are in excellent agreement with experimental evidences, as reported also in [19].…”

“…More recently the possibility of adding electrodes to bend self-confined beams has been investigated both in liquid crystals [18], thanks to their large nonlinearities and in photorefractive materials [24]. An alternative and promising approach takes advantage of intensity modulation inside waveguides to route signals in a stigmergic scheme [19].…”

Addressable Refraction and Curved Soliton Waveguides Using Electric Interfaces

“…The larger the electric bias, the larger the refractive index contrast and the higher the capacity of the refractive structure written by the soliton to confine a signal beam. At the solitonic regime (27 kV/cm), losses reach the lowest limit of 0.07 dB/cm, value already found previously [9][10][11][12][13][14][15][16][17][18][19][20][21]. Such value seems to be the reference limit for all cases.…”

“…The solitonic technology is rapidly opening doors to a new circuit geometry for integrated photonics, using very low loss waveguides, addressable and plastic, in the sense that they are modifiable according to the external stimuli that are sent to them [19,22,23].…”

“…We performed numerical experiments of propagation of soliton beams in biased media using a well-tested FDTD numerical code [19]. The experimental configuration considers a visible beam at 532 nm entering a material with saturable electro-optic nonlinearity, to which a static electric bias is applied.…”