Picosecond optical sampling

Abstract

A high speed sampling technique is proposed using a cascade of optical waveguide interferometers driven by CW sinusoidal traveling or standing microwaves. Each interferometer multiplies the optical signal by a function closely approximated by <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\cos^{4} \omegat</tex> , where ω is the frequency of its microwave drive. A cascade of four interferometers with 2.6 V microwave drives at 10, 20, 40, and 80 GHz and a total length of 2 cm can sample an optical signal with 2 ps resolution and 50 ps between samples. The sampler might be used in a picosecond sampling oscilloscope or in experiments requiring a jitter-free train of identical pulses.