Photosensitive terpolymer based on PFS:PFOA:GMA monomers for optical communications

A photosensitive terpolymeric composition suitable for practical waveguide devices is provided. The terpolymer was produced from pentafluorostyrene (PFS), perfluoro-n-octyl acrylate (PFOA), and glycidyl methacrylate (GMA). We present a fabrication process where the device structure utilizes the same class of material for the core and cladding layers and it was fabricated without a plasma etching process. We also present simulation results that show good agreement with measured data and which thus permit to optimize the device performance. Based on the developed material and process; a 16-channel arrayed waveguide grating (AWG) multiplexer with excellent performance has been realized. The channel spacing of the multiplexer is 0.8 nm and operating around the 1550 nm wavelength. Together the developed material and process combine to produce AWG with an average insertion loss of 5 dB, the best channel shows an insertion loss of 4.7 dB; the uniformity of 1 dB, a crosstalk of less than-28 dB and a polarization dependence loss (PDL) of ∼0.2 dB. During temperature cycling, a slight thickness hysteresis and refractive index hysteresis were observed above the glass transition temperature and is ascribed to the fact that the terpolymer material may not completely recover its elasticity in the heating/cooling cycle.