Fiber stretchers, also called phase shifters, offer the attractive feature to tune and modulate the path length of the light within the fiber core and so the resulting optical delay does. They are based on voltage-driven Piezo ceramics and need to be controlled with proper electronics drivers. Any type of fiber may be assembled, please ask.

Their compact packaging makes them suitable for various system applications. Typical applications include variable optical delay, fiber interferometry, ultra-fast dynamics and lasers.

https://www.idil-fibres-optiques.com/product/fiber-stretcher-2/