We demonstrate experimentally ultrafast three-photon counting by three-photon absorption in a GaAsP photomultiplier tube at the wavelength range of 1800-1900 nm, and analyze its sensitivity and time response. Pulse energy of ∼500 fJ is shown to be detectable for ultrafast 170 fs pulses. The presented three-photon counter may serve as a unique tool for ultrafast quantum state characterization as well as for ultrasensitive third-order temporal measurements.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics