Multi-purpose constant-delay optical link

An electro-optical system for a multi-purpose user signal distribution with a temperature-drift compensation of a fiber link is presented. The delay drift is measured by a radio frequency RF phase comparison. A (coarse) wavelength division multiplexing (C)WDM technology is used for combining compensation and user signals. Temperature and other delay variations (e. g. vibrations) are compensated by an internal heated/cooled fiber spool and/or piezo-controlled fiber stretcher. A delay stability better than 1 ps peak-peak in a 16 hour period has been measured using a dedicated measurement setup. The system uses standard commercially available telecommunication optical components.