In this work, spontaneous four-wave mixing in silica optical nanofibers is studied theoretically. The spectrum of generated biphoton field and its dependence on the nanofiber temperature are analysed.
Abstract Joint spectral intensity of the biphoton field generated via spontaneous four-wave mixing in an optical nanofiber was studied both experimentally and theoretically. The measured two-photon frequency distribution agrees well with the theoretically expected one that is calculated taking into account the spatially inhomogeneous profile of the taper. It is shown that measuring joint spectral intensity of the biphoton field makes it possible to determine the nanofiber radius with high accuracy.
A theory of single-photon sources of light is developed on the basis of spontaneous four-wave mixing in optical nanofibers. The spectral amplitude of the biphoton field is calculated with allowance for the real geometry of a nanofiber manufactured from standard optical fiber by heating and stretching. It is shown that by selecting pump parameters, we can simultaneously obtain the high spectral brightness and low frequency correlation of generated biphoton states in a nondegenerate mode of four-wave mixing that corresponds to single-photon states with the high purity.
Abstract Spontaneous four-wave mixing (SFWM) in optical micro-/nanofibers is studied theoretically and experimentally. Joint spectral intensity of the biphoton field generated via SFWM under excitation of femtosecond laser pulses is measured and calculated considering self-phase modulation of the pump pulses and SFWM throughout the tapered fibers. In comparison with the previous study (Shukhin et al 2020 Phys. Rev. A 101 053822), replacing picosecond pump by a femtosecond one with the same average power makes it possible to increase the photon pair generation rate tenfold.
Subwavelength optical micro/nanofibers have been widely used as basic building blocks in the field of quantum sensing and quantum light source by virtue of their properties which include pronounced evanescent field, large surface area, and small optical mode area. This paper presents theoretical studies on the propagation properties of the guided optical wave and the spectral properties of entangled photons from spontaneous four-wave mixing in micro/nanofibers. We first analyze numerically single-mode propagation, field distribution, fraction of power, and group-velocity-dispersions by solving Maxwell’s equations with boundary conditions in cylindrical coordinates. Then, optical wave guiding properties of micro/nanofibers are applied to estimate the spectral properties such as central wavelengths and bandwidths of the created photons via spontaneous four-wave mixing that can be tailored by controlling diameter and length of micro/nanofibers. This theoretical work provides useful guidelines to design micro/nanofiber-based quantum sensing and quantum light sources for quantum technologies.