Programmable wavelength-tunable second-order optical temporal differentiator based on a linearly chirped fiber Bragg grating and a digital thermal controller.

We proposed and experimentally demonstrated an all-fiber structured wavelength-tunable second-order optical temporal differentiator based on a linearly chirped fiber Bragg grating and a digital-controlled thermal array. The central frequency of the differentiation can be reconfigured from 192.141 to 192.616 THz by a programmable circuit. In the experiment, a second-order differentiator with 3 dB bandwidth of 0.086 THz is achieved with a root mean square error of 4.89%.