TUNABLE OPTICAL DELAY-LINE BASED ON A FIBER BRAGG GRATING

A tunable fibre optic delay line is demonstrated using a uniform fibre Bragg gratin. A segment of the grating: is heated, increasing its Bra gg wavelength so that a signal propagating outside the nominal stop-ba nd is reflected From that point. The position of the heater along the length of thr grating determines the time delay encountered by the sig nal. For a 10 cm apodised grating. a delay of up to 700 ps was obtaine d.