Second harmonic and terahertz generation in a Prussian-blue-analog.

Second-harmonic and terahertz generation is performed in the Rb0.94Mn[Fe(CN)(6)](0.98)center dot 0.3H(2)O Prussian-blue analogue. Second-harmonic generation experiments are carried out between 1100 and 1700 nm and within the hysteresis loop of this compound. In the low-and high-temperature phases, our measurements indicate that the effective second-order nonlinear component chi((2)) of this material is small, compared with a-quartz. However, in the high-temperature phase and close to 1100 nm, its chi((2)) is enhanced by more than one order of magnitude. Terahertz generation indicates that in this frequency range, the effective chi((2)) of this compound is high and comparable with that of ZnTe. Finally, we demonstrate that within the thermal hysteresis loop of this Prussian-blue analogue, one can modulate the chi((2)) by photoswitching it from the low-temperature to the high-temperature phase.