[We-P] Quantum optics, quantum emitters, NV centers

[We-P-83] High-SNR and Femtosecond-Resolved Measurement of Photon Echoes from InAs Quantum Dots Using Up-Conversion Single-Photon Lock-In Detection

〇Rei Ishihara¹, Yuta Kochi^1,2, Ryo Tamaki^1,2, Sunao Kurimura³, Kouichi Akahane⁴, Junko Ishi-Hayase^1,2 (1. Keio Univ. (Japan), 2. Keio CSRN (Japan), 3. NIMS (Japan), 4. NICT (Japan))

We report the first demonstration of femtosecond-resolved photon echo measurements using up-conversion single-photon lock-in detection. This technique reconstructs ultra-weak signals from quantum dots under intense noise, achieving a ten-fold SNR improvement and approaching the shot-noise limit.