Quasi-phase-matched difference-frequency generation in periodically poled Ti:LiNbO(3) channel waveguides

Mid-infrared radiation near 2.8 mum was generated by difference-frequency generation in an 80-mm-long periodically poled Ti:LiNbO(3) channel waveguide by pump radiation near 1.55 mum (tunable external-cavity laser) and a signal radiation of 3.391 mum (HeNe laser). We obtained a normalized conversion efficiency of 105% W(-1) , which is to our knowledge the highest value ever reported.     

Unprecedented stabilisation of the Ag2(2+)-ion by two hydrido-iridium(III) complexes

The complex [[(eta 5-C5Me5)(Ph3P)Ir(mu-H)2]2Ag2(OSO2CF3)2], containing the Ag2(2+)-ion, has been synthesized; crystallographic and spectroscopic data are described.     

Tunable polarization response of a planar asymmetric-spiral infrared antenna

We present measurements at 10.6 microm that demonstrate electronic tuning of the polarization response of asymmetric-spiral infrared antennas connected to Ni-NiO-Ni diodes. Continuous variation of the bias voltage applied to the diode results in a rotation of the principal axis of the polarization ellipse of the spiral antenna. A 90 degrees tuning range is measured for a bias voltage that varies from -160 to +160 mV .This effect is caused by a small asymmetry of the deposited diode contact or by a variation of the detector capacitance with the applied bias voltage.