Picosecond time-interval measurement and intensity correlations using the two-quantum photoelectric effect

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

“…An autocorrelator based on the twophoton absorption of a photomultiplier photocathode has been developed for the measurement of a femtosecond pulse [3]. This approach does not require phase matching and is easily used in routine work [4][5][6][7].…”

Femtosecond Two-Photon Response Dynamics of Photomultiplier Tubes

“…Recently, the two-photon-induced responses of photodetectors are attracting much attention because of their application in pulse-width measurements of ultrashort optical pulses. [1][2][3][4][5][6] Two-photon-induced photocurrent in photodiodes (PDs), [1][2][3] light-emitting diodes (LEDs), 4) and photomultiplier tubes (PMTs) 5,6) has been used for intensity autocorrelation measurements of picosecond or femtosecond optical pulses. This technique has greatly simplified the autocorrelation measurements, which were conventionally carried out using a second-harmonic-generation crystal, a wavelengthselective optical filter, and a sensitive photodetector.…”

Autocorrelation Measurement of Femtosecond Optical Pulses Based on Two-Photon Photoemission in a Photomultiplier Tube

“…Two-photon-induced photoemission from photocathodes of PMTs has been observed, 10,11) and autocorrelation measurements of picosecond optical pulses have already been reported. 12,13) However, no studies have been reported on the femtosecond response of the two-photoninduced processes in PMTs, or on autocorrelation measurements of 800 nm light from Ti:sapphire lasers, which are widely used as femtosecond pulsed light sources.…”