Research

Optical processing unit (OPU)

The technical limitations of miniaturizing transistor size and reducing energy consumption are serious problems. To overcome these issues, parallel computing technology and specialized processor such as DSP(Digital signal processor) and GPU(Graphics processing unit) are paid much attention. Nevertheless, it is difficult to obtain the much faster and less power operation if we continue to rely on conventional electronical technology.

One candidate to get over such difficulties is photonic approach. Lightwave is able to communicate fast (free from RC time constant) and has large data capacity (frequency is very higher than one of electronic device). However, natures of electronics and optics are completely different. Many researchers have been facing various problems in the realization of the conventional function by photonics. Therefore, we are trying to develop the various photonic circuits that can help the progress of electronics.

[Reference]

[1] T. Sato et al., “Design of a reflection-suppressed all-optical diode based on asymmetric L-shaped nonlinear photonic crystal cavity,” J. Opt. Soc. Am. B, OSA, vol. 33, no. 1, pp. 54–61, Jan. 2016. [Author's accepted manuscript]

[2] T. Sato et al., “Design of a high-forward-transmission all-optical diode based on cascaded side-coupled photonic crystal cavities,” J. Opt. Soc. Am. B, OSA, vol. 34, no. 12, pp. 2493–2500, Dec. 2017. [Abstract]

[3] T. Sato et al., “Investigation of optical isolator based on photonic intraband transition using one-dimensional photonic crystal optical waveguide,” IEICE General Conference, C-3-27, Tokyo, 2018. (in Japanese)