Electro-optic spectral-temporal shaping of single-photon pulse

Spectral-temporal modes of quantum light have been recognized as a promising platform for quantum information processing (QIP) and metrology [1]. However, a simple general tool for efficient conversion between spectral-temporal modes is still missing. A phase-only, i.e. in-principle lossless, approach is required for quantum light. I will show that transformations between spectral-temporal modes can be realized by a single application of arbitrary temporal phase modulation and a single application of arbitrary spectral phase modulation. The required arbitrary phases can be found by means of the well-known phase retrieval algorithm, such as the Gerchberg-Saxton algorithm. We apply machine learning-based optimization to find slowly varying phases, opening the way to experimental implementation using wide-bandwidth electro-optic phase modulation [2]. I will also discuss strategies to detect temporal properties of short single-photon optical pulses [3,4].

[1]    M. Karpiński, A. O. C. Davis, F. Sośnicki, V. Thiel, B. J. Smith, “Control and measurement of quantum light pulses for quantum information science and technology,” Adv. Quantum Technol. 4, 2000150 (2021).

[2]    F. Sośnicki, M. Mikołajczyk, A. Golestani, M. Karpiński, “Interface between picosecond and nanosecond quantum light pulses,” Nature Photon. 17, 761 (2023).
[3]    A. Golestani, A. O. C. Davis, F. Sośnicki, M. Mikołajczyk, N. Treps, M. Karpiński, “Electro-optic Fourier transform chronometry of pulsed quantum light,” Phys. Rev. Lett. 129, 123605 (2022).
[4]    A. Widomski, M. Ogrodnik, M. Karpiński, “Efficient detection of multidimensional single-photon time-bin superpositions,” Optica 11, 926 (2024).