Abstract

Most current techniques for the determination of the characteristics of subpicosecond laser pulses involve an optical nonlinearity with a femtosecond response time. Unfortunately, broadband nonlinearities are generally weak and require intense ultrashort pulses. Some compromise between bandwidth and the magnitude of the nonlinear response can be made through the use of a phase-matched crystal. However, there exists a need for an electronic device that could cover a broad range of wavelengths. Progress in this direction was demonstrated by Li et al., who used a GaAs Schottky photodiode monolithically integrated with a microwave detector to perform correlations of picosecond optical pulses.¹ In this work, we extend the attainable temporal resolution with this same device to the femtosecond regime, using it in a frequency-domain measurement, which measures the first derivative of the spectral phase ϕ′(Ω) via a cross correlation of the pulse and spectrally filtered slices of the same pulse.² To our knowledge, this is the first direct measurement of the amplitude and phase of a femtosecond pulse employing only an integrated optoelectronic circuit.

© 1996 Optical Society of America