Li, JiaminSu, JieCui, LiangXie, TianqiOu, Z. Y.Li, Xiaoying2022-02-242022-02-242020-05-18Li, J., Su, J., Cui, L., Xie, T., Ou, Z. Y., & Li, X. (2020). Generation of pure-state single photons with high heralding efficiency by using a three-stage nonlinear interferometer. Applied Physics Letters, 116(20), 204002. https://doi.org/10.1063/5.00036010003-6951https://hdl.handle.net/1805/27925We experimentally study a fiber-based three-stage nonlinear interferometer and demonstrate its application in generating heralded single photons with high efficiency and purity by spectral engineering. We obtain a heralding efficiency of 90% at a brightness of 0.039 photons/pulse. The purity of the source is checked by two-photon Hong-Ou-Mandel interference with a visibility of 95 ± 6% (after correcting Raman scattering and multi-pair events). Our investigation indicates that the heralded source of single photons produced by the three-stage nonlinear interferometer has the advantages of high purity, high heralding efficiency, high brightness, and flexibility in wavelength and bandwidth selection.enPublisher Policythree-stage non-linear inerferometerpure-state single photonsinerferometerArticle