Study of silicon organic EO crystal hybrid wavelength filters for application as dynamic WH TS encoder

Abstract

The increasing bandwidth demand due to emerging IoT (Internet of Things) applications, high bandwidth distributed computing and mobile backhaul, is leading to the requirement of high bandwidth dynamic provisioning even in the access networks. The high density of components needed and the requirement of keeping the costs low requires new high speed newlinereconfigurable device implementations specifically geared for application in these networks. One powerful approach for providing low cost multiple access programmably is to use incoherent 2-D (Two dimensional) WH-TS OCDMA (wavelength-hopping-time spread optical code division multiple access) encoding scheme . However none of the device implementations so far gives complete reconfigurability and control in terms of the number of wavelengths used in the code, or changes in their coding sequence. This work looks at a novel alternative, a single device based on silicon-electro-optic hybrid filter design that satisfies all these requirements. This wavelength selective reconfigurable filter design is a 1-D (one dimensional) photonic crystal based silicon fabry-perot waveguide filter. This filter utilises the (2) nonlinearity of a transparent organic electro-optic crystal grown in-situ in the submicron photonic crystal cavities, for fast low power wavelength selectivity. The speed at which the wavelength selection needs to change is determined by the bit sequence of the code which runs during the time period of the actual data. (The time period (T) of the original user data is broken by the code ( a sequence of 1 s and 0 s), into a number of smaller time slices(N). The time chip rate is then by definition =N/T. This rate determines the maximum speed at which the wavelength needs to be changed. The original newlinedata after being chipped by the code sequence is called the time chipped data or the time encoded data. The time chipped data, with the wavelength of transmission altered during each chip duration, is the wavelength hopping time encoded data or 2D WH-TS data) newline newline