Optical devices for ultra-compact photonic integrated circuits based on III-V/polymer nanowires.

We demonstrated the potential application of III-V/polymer nanowires for photonic integrated circuits in a previous paper. Hereby, we report the use of a spot size converter based on 2D reverse nanotaper structure in order to improve the coupling efficiency between the nanowire and optical fiber. A total coupling enhancement of up to a factor 60 has been measured from an 80 nm x 300 nm cross-section tip which feeds an 300 nm-side square nanowire at its both ends. Simultaneously, micro-radius bends have been fabricated to increase the circuit density; for a radius of 5 microm, the 90 masculine bend losses were measured as low as 0.60 dB and 0.80 dB for TE and TM polarizations respectively.