Hybrid superprism with low insertion losses and suppressed cross-talk

Hybrid superprism with low insertion losses and suppressed cross-talk

Representation of a mode matching interface between a planar photonic crystal and a slab waveguide that allows broadband light insertion with a high efficiency (a) and k-space representation of the coupling mechanism (b).

Abstract:
We demonstrate with the two-dimensional finite-difference time-domain method that an adiabatic transition in a superprism with an interface along the [1 2̅ ] direction enhances the transmission through the superprism to more than 90% (−0.5 dB) over the wavelength range 1.47–1.68 μm, including the telecommunication C and L bands. We also show that diffraction governed by a quasinegative index of refraction inside the superprism can be used to obtain nearly transform-limited beam widths at the output of the superprism. The reduction of the beam width at the output suppresses cross-talk and greatly enhances the achievable frequency resolution of the superprism.
J. Witzens, T. Baehr-Jones, and A. Scherer, Hybrid superprism with low insertion losses and suppressed cross-talk, Phys. Rev. E 71, 026604 1-9 (2005).