Efficient training of a 128-modes 3D continuously coupled photonic chip via limited quantum resources

arXiv:2611.05681v1 Announce Type: new Abstract: Integrated photonics provides a promising route towards the development of large-scale, stable and low-loss quantum hardware. Existing implementations of universal quantum photonic chips generally rely on architectures consisting of localised interactions between the modes that can be programmed with known algorithms to implement specific operations. Recent advances have shown that interferometers based on 3D continuously coupled waveguide arrays may allow to significantly scale up the number of modes with reduced overhead. However, for this class of devices, optimal strategies to set the controllable parameters and obtain the desired transformation have not been demonstrated generally.