My research interest includes various applications by the photonic integrated circuits, especially for the optical communication system and analogue computing system.
Mode-division multiplexing (MDM) technology plays a key role in boosting the transmission capacity of the next-generation optical communication systems. In MDM systems, mode coupling occurs inevitably inside the multi-mode fibers (MMF), as well as within the mode multiplexers (MUX) and demultiplexers (DEMUX) at the transceivers and repeaters. It is, therefore, necessary to unscramble these coupled modes at the receiver end through a multi-input-and-multi-output (MIMO) process. The optical MIMO can achieve this process with almost zero power and independent of modulation way. In order to implement this attractive optical MIMO, the reconfigurable optical matrix multiplexer, that is optical unitary converter is essential.
Related papers
R. Tanomura, R.Tang, T. Umezaki, G. Soma, T. Tanemura, Y. Nakano, "Scalable and Robust Integrated Unitary Converter based on Multiplane Light Conversion," Phys. Rev. Appl., vol. 17, no.2, art. 024071, Feb. 2022. [link] / arxiv ver; [link]
R. Tanomura, R.Tang*, S.Ghosh, T.Tanemura, Y.Nakano, “Robust Integrated Optical Unitary Converter using Multiport Directional Couplers, ” J. Lightw. Technol., vol.38, no. 1, pp.60-66, Jan. 2020 [pdf]
〇R. Tanomura, R. Tang, T. Tanemura, Y. Nakano, “Monolithic InP 4×4 Optical Unitary Converter for All-Optical MIMO Demultiplexing, ” European Conference on Optical Communication(ECOC), Dublin, Ireland, Sept. 2019, P49 [pdf]
〇R. Tanomura, R. Tang, T. Tanemura, Y. Nakano, “Compact Reconfigurable Optical Unitary Converter based on Non-Uniform Multimode Interference Coupler, ” Photonics Switching and Computing conference (PSC), Fukuoka, Japan, July. 2019 , TuF3.1 [pdf]
〇R. Tanomura, R. Tang, S.Ghosh T. Tanemura, Y.Nakano, “Integrated Reconfigurable 4×4 Optical Unitary Converter Using Multiport Directional Couplers, ” Optical Fiber and Communication Conference (OFC), San Diego, USA, March. 2019, Th1E.3 [pdf] (Corning Outstanding Student Paper Award Grand Prize)
Neural network (NN) is getting much interest for the diverse fields, including medicine, automobile, fundamental science, image classification, and so on. However, it has shortcomings in terms of power consumption and calculation speed, and programmable photonic circuits are expected to be used as new NN hardware. As a programmable photonic circuit, OUC can be used as an optical NN platform by realizing arbitrary linear operations connecting each layer of NN according to the principle of singular value decomposition.
Related papers
R. Tanomura, R.Tang, T. Umezaki, G. Soma, T. Tanemura, Y. Nakano, "Scalable and Robust Integrated Unitary Converter," arXiv 2103:14782 (preprint) [pdf]
R. Tanomura, R.Tang*, S.Ghosh, T.Tanemura, Y.Nakano, “Robust Integrated Optical Unitary Converter using Multiport Directional Couplers, ” J. Lightw. Technol., vol.38, no. 1, pp.60-66, Jan. 2020 [pdf]
〇R. Tanomura, R. Tang, T. Tanemura, and Y. Nakano, “Robustness analysis of generalized optical unitary converter,” IEEE photonics society summer topical meetings, online, TuB4.4, Accepted.
〇R. Tanomura, R. Tang, T. Tanemura, Y. Nakano, “Scalability of Universal Nanophootnic Processing Circuits based on Multi-Plane Light Conversion, ” Conference on Laser and Electro Optics (CLEO), SanJose, USA, May. 2020, JTh2B.28 [pdf]
An integrated polarization rotator (PR) is one of the key components for realizing the polarization diversity inside one chip. Silicon photonics has strong light confinement and makes possible it to realize difficult structures.
Related papers
〇R. Tanomura, A. E. Elifiq, D. Yu, W. Yanwachirakul, H. Shao, Y. Suzuki, T. Tanemura, Y. Nakano, "Mode-Evolution-based InP/InGaAsP Polarization Rotator with Etching-Stop Layer, " Optical Fiber and Communication conference (OFC), online, June.2021, Tu1C.2.