Ellipsometry was used to measure the amplitude ratio and phase difference of light undergoing a phase shift as it interacts with a thin film of organic–inorganic hybrid perovskite CH3NH3PbI3 (MAPI) deposited onto a (100) silicon wafer. The refractive index and extinction coefficient was extracted from a multi-oscillator model fit to the ellipsometry data, as a function of wavelength, from 300 to 1500 nm.

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Abstract. Polymer tapered multimode waveguides were modeled using the finite difference wide-angle beam propagation method to investigate whether tapered input waveguide couplers decreasing in width away from the waveguide entrance give improved tolerance to lateral misalignments of an optical source compared to straight waveguides and whether there is any effect on angular misalignment tolerance for use in optical backplane interconnections. Input tapered couplers having a larger entrance and tapering down in width do indeed improve the lateral misalignment tolerance compared to straight waveguides but do so at the expense of an increased loss. Tapers have no effect on angular tolerance for strongly driven vertical cavity surface-emitting laser ͑VCSEL͒ sources although they cause a loss of angular tolerance for single-mode fiber sources and VCSELs at low drive currents. © 2007 Society of Photo-Optical Instrumentation Engineers.

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A 0.4 dB excess loss, 0.01 dB output channel imbalance polymer 1 3 MMI power splitter is modeled having linearly tapered input section suitable for use in an optical backplane connector. The device design was additionally optimized using FD-BPM to have a good tolerance to source lateral misalignments.