Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

Research Outline: Light has been used for various applications including imaging, precision measurements, information processing, and electric power generation. In the near future, those technologies can be drastically improved by meeting “quantum states of lights”such as photons. Indeed, information processing applied quantum optics and physics, has established “quantum information science” that is expected to realize drastically fast computing and high security communication systems. My big goal is to “familiarize” many other disciplines of sciences and industries with “quantumness.”

As opposed to classical states of lights (such as laser lights), photons are very fragile; you cannot copy or amplify, and thereby cannot recover them once you lose (though surprisingly this can be beneficial for some applications). Therefore, lossless and on-demand generation of single photons is very important for practical quantum applications. However, efficiencies of single-photon emitters have not been improved much for 20 years.

In order to realize on-demand generation of single photons, I propose to “multiplex” a bunch of such inefficient single-photon sources by using optical switches. To do so, first I will develop optical switches that can change colors, arrival times, polarization and etc., of photons with ultra-low loss. As an interdisciplinary application of on-demand multiplexed photon sources, I will investigate response of biological tissues single- and multi-photon states.