We demonstrate a new technique of reconfigurable demultiplexing of optical time-division-multiplexing (OTDM) signal. The operation is achieved by pump depletion in an optical parametric amplifier using probe pulses from a time- and wavelength-interleaved laser source. Error-free operations have been achieved for both adjacent and alternate two-channel demultiplexing with power penalties less than 0.6 dB at 40 Gb/s.