Bend loss and Transmission Loss by Defective Layer Air Holes in PCF Using 2D FDTD Method: A Simplest Model
We proposed to design a suitable PCF and studied the additional loss due to the inner surface imperfection like contamination and surface roughness of PCF air holes. We also investigated the modal loss relies on imperfection using a model with a defective layer for the first time using 2D FDTD method. The proposed investigation offers that HOM has more loss as compared to FM due to the imperfection in the PCF air holes. In fact by reducing the inner surface imperfection of six innermost air holes and expect to consider the negligible level of additional loss. We also fabricated few mode PCFs by introducing a suitable inner surface treatment for six innermost air holes and predicts that the transmission loss was exactly greatly reduced by this process and the transmission losses in 1.55 µm wavelength were 0.27 dB/km for FM and 0.37 dB/km for HOM. Henceforth our proposed model will be suitable in view to realizing few mode PCF with loss comparable to conventional fibre.