Continuously Tunable Wideband Delay Line Based on a Cumulative Grating Matrix

A continuously tunable passive delay line based on a multichannel grating matrix is demonstrated. The wideband delay line is capable of providing continuous relative delays up to 60 ns with an accuracy of 100 ps. The topology is reconfigurable and expandable to provide arbitrary delay ranges and resolutions, and supports high speed tuning through the use of tunable semiconductor lasers. High cross-channel isolation and the ability to support multiple, simultaneous delays are also features of this simple, reliable topology.