Light confinement in low contrast slot waveguide structures investigated

The advent of slot waveguide structure has led the field of nano-photonics into an era, where maximum light can be confined inside low index slot guarded by high index slabs. Already in use slot waveguides (contrast ratio is 2.42) have two distinct properties over the conventional waveguides, i.e. high E-field amplitude, optical power, optical intensity in low index materials and a strong E-field confinement is localized to nanometer-size low index regions. We hereby propose a low contrast double slot waveguide structure (contrast ratio is 1.65); where low index slots comprising of air surrounded with high index glass slabs. The whole structure is based on substrate comprising of glass whereas cladding is of air. Novelty lies in showing high E-field amplitude, optical power, optical intensity and a strong E-field confinement in low index slot regions. Low contrast double slot structure usage in forming passive nano-devices had been verified by simulating a Y-branch coupler.