A single-shot measurement of a picosecond optical pulse waveform

A waveform monitoring for a picoseconds-width, single-shot optical pulse is possible with optical circuit of optical fibers and LiTaO3 Pockel's cell. This method is based on having cross correlation integral between delayed signals and a single step function. The inquired waveform is reproduced by a deconvolution. The principle can be implemented by four fundamental functions, branching to make replicas of a source signal, delay, optical gate, and time integration. Optical fibers were employed as delay lines whose delay time is controlled by their length. A small cylindrical lens was used for the branching from a single optical fiber to a bundle of fibers as delay lines. The optical gate is composed of a LiTaO3 Pockel's cell which is driven by a specifically manufactured optoelectronic switch. The time integration is achieved by photodiodes whose electric charge output is proportional to the energy, a time integral of temporal power, of the incident optical pulse. Experiments were made for a 2ns FWHM optical pulse of a dye laser, which demonstrates the expected ability. Very fast A/D conversion for a picosecond optical pulse waveform is basically possible, which is more profittable than a pure electronic metnod.