Patent attributes
A multichannel optical coupler array can include a coupler housing structure and longitudinal waveguides. At least one of the longitudinal waveguides can be a vanishing core waveguide having an inner vanishing core having a first refractive index (N-1), an outer core having a second refractive index (N-2), and an outer cladding having a third refractive index (N-3). A refractive index transition between N-1 and N-2 can have a function form N(r), where r is a transverse distance from the inner vanishing core center. The function N(r) can be a smooth function having a positive average of the second derivative or function N(r) can be a step function with at least one step approximating the smooth function. The coupler housing structure may have non-circular holes formed by convex-shaped housing structure elements.
