Polymer optical waveguide devices are getting popular for next generation FTTH application. In order to accelerate the development of polymer optical devices, evaluation of waveguide characteristics should be speeded up. Polymer optical chip containing a combination of 45°-angled cut waveguide, Y-splitter and S-bend structures was designed and fabricated for simple evaluation of multimode waveguides. Input launching such as light source, mode scrambler was investigated for reliable measurement.
We have developed several novel polymer materials for optical waveguides. In the first part of this paper, we described two examples of our developed materials, one is low loss optical waveguide materials for optical communications at near infrared wavelength region, the other is low loss and high heat resistant materials for optical interconnections in the electronic devices at around 850 nm wavelength region, which can resist to the lead-free solder reflowing process. In the second part, we demonstrated two kinds of novel low cost polymer coarse wavelength division multiplexing (CWDM) devices, one is the polymer arrayed waveguide grating (AWG) device and the other is the polymer CWDM device using the polymer diffraction grating. The structures and performances of these devices were described in detail.
Xanthone derivatives have been found to be new organic nonlinear materials
with a high efficiency of second harmonic generation (SHG) and transparency
in visible region. For example, 3-aminoxanthone had a high SHG activity
(SHG emission of this sample was 1 3 times higher than that of urea ) and good
thermal stability (mp=232 C ) . A single crystal of this sample was transparent
above 430nm. The SHG properties for other xanthone derivatives were also
Nonlinear susceptibilities of organic crystals are usually calculated from the
molecular nonlinearities(hyperpolarizabilities) and the crystal structure data within
the oriented gas model approximation. The effect of intermolecular interactions on
hyperpolarizabilities, which is neglected in the approximation, is estimated
quantitatively by using an ab initio molecular orbital(MO) method. Energy minimum
crystal structures of typical organic nonlinear optical materials are calculated by
an empirical atom-atom pairwise potential method.