Synthesis, optical nonlinearity and crystal structure of a novel mixed-chalcogen, thiolato-bridged complex [(eta(5)-C5H5)(2)Mo-2(mu-S)(mu-Te)(mu-SPh)(2)]

A novel dimolybdenum complex in which the metal atoms are bridged by two different chalcogens and two thiolato ligands has been synthesised and structurally characterised. This complex shows a large third-order optical nonlinearity as measured by degenerate four-wave mixing with picosecond excitation at 532 nm. A hyperpolarisability (gamma) of 1.2 x 10(-30) esu has been obtained. The structure of the complex was established by the single-crystal X-ray diffraction method. It consists of a Mo-Mo unit, which is bridged by one S, one Te and two (SPh) groups. Each Mo atom also has a (eta(5)-C5H5) group attached to it. (C) 2000 Elsevier Science S.A.

Autoclaveable miniaturized video endoscopes with simplified flip-chip assembly

Miniaturized video endoscopes with an imager located at the distal end and a simplified opto-mechanical layout are presented. They are based on a CMOS imager with 650 x 650 pixels of 2.8 ?m pitch and provide straight view with 75 ° and 110 ° field of view at f/4.3. They have an outer diameter of 3 mm including the shell and a length of approx. 8 mm. The optics consist of polymer lenses in combination with a GRIN and a dispensed lens. Using a simple flip chip assembly, optical axis alignment better than 10 ?m and a contrast of 30 % at 90 LP/mm was achieved. The 75 ° FOV system was sealed at the front window using a solderjetting technology, providing 10-9 mbar*l/s leakage rates even after several autoclave cycles