503 ns, tunable optical delay of 40 Gb/s RZ-OOK and RZ-DPSK using additional λ-conversion for increased delay and reduced residual dispersion

We demonstrate a tunable optical delay element using wavelength conversion in a highly nonlinear fiber, dispersion compensating fiber, and optical phase conjugation. A continuous delay of up to 503-ns, for RZ-OOK and RZ-DPSK at 40-Gb/s, is demonstrated utilizing an improved method for doubling the relative delay and minimal residual dispersion.