Optical and mechanical aspects on polysiloxane based electrical-optical-circuits-board

3.1 Introduction 15 3.2 Experimental 16 3.3 Refractive index and bandwidth 18 3.4 Optical loss 23 3.4.1 Scattering loss 23 3.4.2 Intrinsic absorption loss by molecule vibrations 25 3.4.3 Estimation of absorption loss 35 3.5 Processing of PDMS optical waveguides 43 3.5.1 Fabrication of PDMS optical waveguides 44 3.5.2 Scattering loss from mould roughness 48 3.5.3 Optical loss due to interlayer 50 3.5.4 Optical loss from packaging substrates 52 3.6 Summary of results of the chapter 55