Inverse-design of high-dimensional quantum optical circuits in a complex medium

Roadmap on multimode photonics

“…Within a more general context, multimode fibers (MMFs) have been investigated in a variety of quantum applications, e.g. highdimensional linear optical circuit manipulation [38], QKD using space encoded technique [39], programmable quantum network [40], entanglement unscrambling [41], and quantum walk application useful for quantum simulation process [42].…”

A high-fidelity and large-scale reconfigurable photonic processor for NISQ applications

“…3D wave mixing in complex media in conjunction with wavefront shaping is a promising alternative approach. The implementation of a simple beam splitter [27][28][29][30] as well as more complex linear circuits [31,32] have been demonstrated. Due to the much larger number of available propagation modes this type of system promises scalability beyond what can reasonably be achieved with * adrien@lighton.io integrated circuits.…”

“…Repeating the procedure for each input leads to the realization of a circuit L exp that can be compared with the targeted L. The possibility of implementing a wide range of circuits is due to the largely isotropic polarization and spatial mode mixing taking place in the MMF, the many availble degrees of freedom on the SLM as well as the unitary nature of the TM. The concept has been presented and used in [31,32] in the context of up to two optical inputs distinct in polarization. Here we report the extension of the system to 8 inputs as well as its characterization.…”

Simultaneously sorting overlapping quantum states of light

“…Two phase screens can be used to convert modes with orbital angular momentum to position modes of light [24,25]. More recently, general unitary operations have been implemented by harnessing mode-mixing in multimode fibers [30] or in free-space using multi-plane light converters (MPLC) [26][27][28]. These devices use multiple phase screens to transform and measure complete sets of orthogonal modes, e.g.…”

“…These devices use multiple phase screens to transform and measure complete sets of orthogonal modes, e.g. Hermite-Gaussian and Laguerre-Gaussian modes [29], as well as implementing quantum gates for high-dimensional modes of light [30][31][32][33]. An extension of this technique to transformations of polarization spatio-temporal optical fields has been demonstrated recently [34].…”