Cerenkov-type second-harmonic generation in thin planar calix[4]arene waveguiding films

A new type of organic molecule, calix[4]arene, is applied in a second-harmonic-generating waveguide device for the first time. Linear optical properties of the calix[4]arene waveguiding film have been measured with the prism-coupling method. The molecules in the film are oriented by a corona-poling technique. With a Maker-fringe experiment, the induced d(33) and d(31) at lambda = 1064 nm are determined at 8.6 and 2.0 pm/V, respectively. The calix[4]arene thin film has been applied to a Cerenkov-type device that generates second-harmonic light radiating into the glass substrate. The highest efficiency obtained is 0.23% for a fundamental wavelength of 820 nm by the use of fundamental power densities of 100 MW/cm(2) in the waveguide and a device length of 6 mm. A coupled-mode theory has been developed that can properly explain the experimentally observed second-harmonic-generating efficiency and the angle of radiation into the substrate. Two methods for the enhancement of device efficiency are proposed, both based on theoretical calculations with the coupled-mode theory. An enhancement of 2 orders of magnitude is feasible. (C) 1995 Optical Society of America