April 16, 2004, Annapolis Junction, MD -- Little Optics Inc., inventor of Hydex, a patented glass high-index optical waveguide material system for planar lightwave circuit (PLC) fabrication, recently announced the availability of 8-bit programmable delay lines. The circuit structure is comprised of a series of crossbar switches that selectively route signals either through a time delay element or through a bypass.
Applications for programmable delay lines include true-time delay signal processors for phased array antennas, optical time domain multiplexing, optical clock distribution, and optical buffering within all-optical routers.
Little Optics uses a "Pick and Place" stepper lithography strategy to selectively place spirals of arbitrary length onto a common bus structure. Little Optics has a library of over 400 long path length spirals ranging from 0.05 cm to 20 cm (corresponding to time delays from ~3 ps to ~1.2 ns) that can be integrated onto a chip that is less than 1 cm2. Using the 8-bit architecture, a device with a maximum time delay of ~2.4 ns can be realized using standard photonic elements. Longer delays or devices with specific requirements can be designed, if not available in the standard device library. Mode transformers are integrated into the PLC for efficient coupling into conventional singlemode fibers.
Little Optics provides embedded controls and a serial communication interface via an RS-232 port for convenient device operation. A graphical user interface software program is provided for time delay selection.
For more information, visit Little Optics' Web site at www.littleoptics.com/delay.pdf.