Abstract: Wavelength converter device for generating a converted radiation at frequency ?g through interaction between at least one signal radiation at frequency ?g and at least one pump radiation at frequency ?g, with an input for the at least one signal radiation at frequency ?g; a pump light source for generating the at least one pump radiation at frequency ?g, an output for taking out the converted radiation at frequency ?g, a structure for transmitting the signal radiation, the structure including one optical resonator having a non-linear material, having an optical length of at least 40*?/2, wavelength ? being the wavelength of the pump radiation, and resonating at the pump, signal and converted frequencies ?p, ?s, and ?g.

Abstract: An electro-optic (EO) device having a high-resistivity semiconducting crystal and a method of operating such a device. The local shielding of the externally applied field lowers the EO effect, which can be partially or completely inhibited particularly in the low-frequency regime, i.e., less than about 105 Hz. By holding a high-resistivity semiconducting crystal at a suitable temperature, EO response and efficiency are improved, in particular for light signals that are non-modulated or modulated at low frequencies. Preferably, the temperature at which the semiconducting crystal is held during functioning is between 50 and 150° C. Enhancement of the EO effect has been demonstrated also for EO devices operating at relatively large optical powers, i.e., larger than about 0.1 mW.

Abstract: Optical switch matrix having at least an input matrix port defining at least a row of the matrix, a plurality of output matrix ports defining columns of the matrix, a plurality of switching elements, each one being disposed at the intersection of at least one row and one of the columns. Each switch element in a predetermined position of the matrix, in an activated condition, connects an input matrix port to an output matrix port, the ports being correspondents respectively to the predetermined position of the matrix.