Integrated-optic dispersion compensator that uses chirped gratings

An integrated-optic dispersion compensator that uses chirped waveguide gratings is designed and fabricated. The 7-mm-long chirped grating is realized by a recently proposed method of curving a waveguide through a uniform grating. At 800 nm, the fabricated device exhibits a reflection bandwidth in excess of 0.5 nm and a nearly quadratic phase response corresponding to a fiber dispersion–length product of 58 ps/nm. The phase response reported is measured interferometrically with a narrow-band, tunable Ti:sapphire laser. Extending this technology to 5-cm-long gratings should permit dispersion compensation of 50-km-long fiber lengths at 1.55 μm.