Measurement of wave function with quantum interference and estimation

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04919
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 30020:Optical engineering and photon science-related
• Research Institution: The University of Electro-Communications
• Principal Investigator: Zhang Yun 電気通信大学, 大学院情報理工学研究科, 教授 (00508830)
• Co-Investigator(Kenkyū-buntansha): 鈴木 淳 電気通信大学, 大学院情報理工学研究科, 准教授 (70565332)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 二光子干渉 / 波動関数 / 量子推定 / 単一光子状態

Outline of Final Research Achievements

We experimentally investigate two-photon interference between a weak coherent state and a heralded single-photon state (thermal state), producing from a spontaneous parametric down conversion. Based the results of interference, we present and experimentally demonstrate a method for determining the spectral characterization of a single-photon state. This technique is based on the Hong-Ou-Mandel interference between a well-defined weak coherent state and a measured single-photon state. We estimate the spectrum of the single-photon state by fitting the measured interference dip with proposed model and least square method. Our method is particularly useful for characterizing spectral property the single-photon state. Furthermore, the purity of the single photon can also be estimated from the width of HOM dip. It opens a way for robust and efficient on-line monitoring the single-photon emitters.

Free Research Field

光工学・光量子科学

Academic Significance and Societal Importance of the Research Achievements

量子力学の原理である重ね合わせおよび干渉するという光科学における新たな理解と知見を得たことができた．量子力学の基本概念，特に光の波動性と粒子子性に関すると深く関わっているからである．現代量子科学技術には量子力学の基本概念をもとつくので，実際にこの研究に生み出された技術には，量子通信の実現するための必要な基盤技術を確立するし, 新たな量子光学の発展および20世紀最後に出てきた量子情報科学の新しい研究分野の革新的展開を引き起こすと期待されている．