Demonstration of a quartic cell, a free-space true-time-delay device based on the white cell

The authors report on a design and demonstration of a quartic-style optical true-time-delay device based on a White cell. This device is designed for 81 sequential time delays with an incremental delay of 243 ps and a maximum delay of 19.683 ns. The time delays are implemented by free-space translations, with lens trains as needed for beam containment. A digital microelectromechanical tilting micromirror array is used to send the light into different delay paths.