QPM-LN-Based 40GHz to 40GHz Switch Using Cascaded Nonlinearities

Recently, there has appeared an attractive candidate for the all-optical switches, which employs the cascaded χ (2) effect in quasi-phase-matched (QPM) LiNbO 3 (LN) waveguides [1] - [4] . In these switches, when the center wavelength of the clock is set to the QPM wavelength, its second harmonic (SH) is generated. Difference frequency mixing between the SH clock and the original signal then produces the wavelength-converted signal. Those potentials have been revealed in a number of experimental demonstrations [1] , [2] , [5] . However, it is still an open question how the pulse waveform or the temporal pulse width of the wavelength-converted signal is affected by those of the input clock and original signal. In this paper, through 40-GHz switching experiments considering the temporal widths of the input pulses, we investigate characteristics of a QPM-LN-based switch.