Ryota Tanomura

An integrated optical unitary converter (OUC), which can realize arbitrary N × N unitary transformation on chip, is promising for widespread applications in various areas, such as optical communication, quantum information processing, and optical neural networks. Most of the integrated OUCs demonstrated to date comprise cascaded 2 × 2 Mach-Zehnder interferometers (MZIs) based on Reck's scheme or its variation, or cascaded multimode interference (MMI) couplers based on multi-plane light conversio

An optical unitary converter (OUC) that can convert a set of $N$ mutually orthogonal optical modes into another set of arbitrary $N$ orthogonal modes is expected to be a key device in diverse applications, including optical communication, deep learning, and quantum computing. While various types of OUC have been demonstrated on photonic integration platforms, the sensitivity against a slight deviation in waveguide dimensions has been the crucial issue in scaling $N$. Here, we demonstrate that an

Integrated reconfigurable optical unitary converters (OUCs) are crucial in realizing all-optical spatial mode demultiplexing for mode-division-multiplexed transmission systems and programmable photonic processing for optical neural networks. In this work, we present the first experimental demonstration of 4×4 OUC monolithically integrated on InP. To avoid the difficulty of integrating a large number of Mach-Zehnder interferometer couplers on the InP platform, we apply the concept of multi-plane

Dual-polarization (DP) arbitrary optical unitary processor (OUP) is a critical device to realize an energy-efficient multi-input-multi-output (MIMO) process of mode-division multiplexed (MDM) systems in the optical domain. In this paper, a 6-port OUP with polarization-splitter-rotators is realized on a compact silicon photonic chip based on the multi-plane light conversion (MPLC) concept. All-optical MIMO demultiplexing of 300-Gbps 3-mode DP quadrature phase-shift-keying (QPSK) signal is demonst

Integrated optical unitary converters (OUCs) are vital devices for various emerging applications such as mode-multiplexed optical communication, optical neural networks, and quantum computing. In order to realize large-scale OUCs in a limited footprint, the number of elements, as well as the size of each element, is important. In this work, we present a novel type of OUC using half-integer multimode interferometers (MMIs) based on the multi-plane light conversion (MPLC) concept. A half-integer M

Abstract An optical unitary processor (OUP) is a programmable photonic circuit to achieve arbitrary unitary operation for various applications, including optical communication, deep learning, and quantum computing. Conventionally, OUPs are implemented by cascading 2 × 2 reconfigurable interferometers, but this scheme cannot easily be extended to multiple wavelength and polarization channels due to the strict requirement to employ 50:50 beam splitters. Here, we demonstrate that an OUP using multi

We demonstrate novel silicon photonic 4×4 reconfigurable optical unitary converter, comprising multiport directional couplers and phase shifter arrays. By optimizing the phase shift with simulated annealing algorithm, reconfigurable mode sorting and switching are experimentally realized.

An integrated optical unitary processor (OUP) that can perform arbitrary unitary mode conversions is expected to be a key device in diverse applications, including optical communication, deep learning, and quantum computing. While integrated OUPs have been experimentally demonstrated, most of them are sensitive to fabrication errors because of their stringent requirements on the splitting ratio of optical splitters. Here, we experimentally demonstrate that the OUP based on multi-plane light conv

Requirement of mode mixers in optical unitary converters based on multi-plane light conversion is examined. The “entropy” of each mixer, which describes the degree of mixing, is revealed to be crucial in determining the performance.

We experimentally demonstrate error-tolerant optical unitary processors with multiport directional couplers. Thanks to the inherent redundancy of the multi-plane light conversion scheme, equivalent performance is obtained in the presence of large fabrication errors.

We investigate the effect of reducing the number of phase-shifting stages in optical neural networks. High data-classification accuracy over 95% is obtained with only 1/10 phase shifters when the multi-plane light-conversion architecture is employed.

We experimentally demonstrate error-tolerant optical unitary processors with multiport directional couplers. Thanks to the inherent redundancy of the multi-plane light conversion scheme, equivalent performance is obtained in the presence of large fabrication errors.

Recent progress of developing universal optical unitary processors (OUPs) based on the concept of multi-plane light conversion (MPLC) is reviewed. The inherent redundancy of MPLC provides unique scalability and excellent robustness against fabrication imperfectness, enabling large-scale OUPs integrated on silicon and InP platforms.

Optical unitary converters (OUC) that enable reconfigurable unitary transformation between the input and output optical bases has gained increased interest for various applications. We compare different architectures of integrated OUC in terms of fabrication tolerance and demonstrate that all-to-all-coupled interferometer significantly enhances the robustness.

Optical unitary converter (OUC) that can convert a set of N mutually orthogonal optical modes into another set of arbitrary N orthogonal modes is expected to be the key device in diverse applications, including the optical communication, deep learning, and quantum computing. While various types of OUC have been demonstrated on photonic integration platforms, its sensitivity against a slight deviation in the waveguide dimension has been the crucial issue in scaling N. Here, we demonstrate that an