Propagation Properties in Short Lengths of Rectangular Epoxy Waveguides

The propagation loss and beam spreading in large core epoxy ridge waveguides on a glass substrate at wavelengths ranging from 630 to 1550 nm has been measured. At the intermediate wavelengths, a loss floor of 1.2 dB/cm is observed which is caused by inclusions and wall imperfections. The theoretical and experimentally determined equilibrium numerical aperture is 0.65 and 0.29 and the modal dispersion is 5.1 and 1.0 ps/cm respectively. The discrepancy is due to strong scattering. The scattering does not give rise to any noticeable mode mixing. The epoxy waveguides also provide a rapid filling of the modes which is attractive for modal noise suppression. © 1992 IEEE