抄録
The time-frequency duality of light is the fundamental concept for ultrafast laser science and technologies.
Although the 1D Fourier transform connects electric field distributions between time and frequency
domains, 1D treatment is insufficient for understanding the behavior of time-frequency entangled
photons. Elucidation of the Fourier duality of entangled-photon wave packets is key for further development
of quantum photonics in the ultrafast regime; unfortunately, it hasn’t yet been demonstrated. Here
we present the duality as it appears in the frequency spectrum and the temporal shape of the entangled-
photon wave packet with two-photon coincidence measurements in the time and frequency domains
to extract two-photon time-frequency distributions. We also estimate the time-bandwidth product values
in 2D time-frequency space to confirm the Fourier-limited conditions of the entangled-photon wave
packets and discuss the prospects of ultrafast quantum optics with time-frequency entangled photons.
