[20a-C43-1~5] 4.7 Quantum Optics, Nonlinear Optics and Structured Optics

10:00 〜 10:30英語発表

[20a-C43-1] [JSAP-Optica Joint Symposia Invited Talk] Femtosecond Region Photon Echo with Quantum Dots via Up-conversion Single-photon Detector

〇Yuta Kochi^1,2, Sunao Kurimura³, Kouichi Akahane⁴, Junko Ishi-Hayase^1,2 (1.Keio Univ., 2.Keio CSRN, 3.NIMS, 4.NICT)

キーワード：

photon echo、nonlinear crystal、quantum dot

Recently, quantum information processing and communications using photons have been attracting attention. To increase the density of transmitted photonic qubits, it is necessary to develop broadband quantum memories and detectors that can handle ultrashort pulses. Although rare-earth-ion doped quantum memories have been widely studied, due to their storage bandwidth of ~GHz, they are incapable of storing ultrashort pulses. In our group, we used the photon echo (PE) method with quantum dots (QDs) to realize ultra-short femtosecond pulse storage. However, we encountered many difficulties in realizing this method such as low PE efficiency from the QDs and the insufficient temporal resolution of the avalanche single-photon detectors. To solve these problems, we have applied a new quantum control method and utilized an up-conversion single-photon detector (UCSPD). In this presentation, we will introduce the techniques “1. Time-resolving measurement by UCSPD,” “2. PE quantum memory using QDs” and “3. enhancement of PE signals.”