Femtosecond Two-Photon Response Dynamics of Photomultiplier Tubes

Abstract

An intermediate state of two-photon photoemission processes in a photomultiplier tube was found and relaxation with a time constant of 270 fs was observed by time-correlated measurements using 15 fs, 800 nm optical pulses. Optical Bloch equation analysis of the signal intensity was carried out using a perturbation method.

Generation of phase-controlled ultraviolet pulses and characterization by a simple autocorrelator setup

“…In the design of a two-photon photoemission based autocorrelator, the possible contribution of resonance enhanced TPA with finite temporal response should always be considered [31]. As the obtained time bandwidth products agree with the cross correlation data of a similar pulse generation setup [25], the acquired autocorrelations should contain negligible pulse broadening effects owing to noninstantaneous detector response.…”

Two-photon QWIPs for quadratic detection of weak mid-infrared laser pulses

“…In the density matrix formalism, the optical Bloch equations provide an appropriate theoretical description [15]. The complexity of this three level system, however, prevents an analytic solution.…”

Autocorrelator for the measurement of a quasi-continuous-wave laser beam sinusoidally modulated at 17 THz

“…A photomultiplier comprised of an Sb-Cs photocathode (Hamamatsu, 1P28, 190-650 nm) was used in this study. This photomultiplier has sufficient sensitivity for a single photon below 650 nm and has no sensitivity in the near-infrared region above 700 nm [8]. The Ti:sapphire laser beam was focused onto a photocathode using a lens with a focal length of 5 cm.…”