Abstract

A sub-Planck structure from Compass states, composited by four coherent states in superposition, is reported experimentally through the correspondence between Wigner distribution function and frequency-resolved optical gating (FROG) measurement. Demonstration on the chessboard-like patterns with a time-bandwidth product smaller than that of a transform-limited pulse is realized through simultaneously sufficient time and frequency separations among optical pulses. The sub-Planck structure in the interference pattern from Compass states not only manifests itself as a generalized Schödinger's cat state, but also provides the platform to exploit quantum metrology and quantum information processing through ultrafast optics.

© 2015 Optical Society of America