Optical Autocorrelation Measurement for Ultrafast Pulses at NIR Wavelengths Using GaP, GaAsP, and Si Photoconductive Detectors

In this article, we report on an optical real-time autocorrelator readout with a 5 Hz refresh rate, equipped transimpedance amplified photodetector based the two-photon absorption (TPA) of semiconductor photodiodes (PDs) for ultrashort (1 < ps) pulse measurement. By replacing GaP PD commercial TPA detector GaAsP and Si elements, demonstrated that spectral response each followed linear corresponding within accessible wavelength regions. The exhibited peak at 1200 nm long limit near 1300 nm. short 1170 up to two types were compared characteristics photodiode. These photoconductive detectors are efficient, compact, robust sensors can be used diagnose ultrafast fiber lasers light sources IR wavelengths.