Dispersion-order selectable chromatic dispersion compensator using strain-profile modification blocks

A new method for tuning the dispersion profile of a fiber grating is described. The method involves compressing the fiber grating attached to a structure in which the cross-sectional area varies with its position. Because the cross-sectional area defines the compression rate, the local Bragg reflection wavelength that determines the dispersion profile varies along the position. A structure in which the cross-sectional area can be simply altered by inserting-extracting a part of structure was designed. Therefore, the dispersion order of the fiber grating attached to the structure can be selected. Using the method, a linearly-quadratically chirped fiber grating was made and various group delay slopes depending on the applied stress were obtained.