One-step fabrication of micro-deflector and optical waveguide by femtosecond two-photon polymerization

We present simultaneous fabrication of micro-deflector and optical waveguide using femtosecond two photon polymerization technique. Parallelepiped-shaped waveguide was created which may serve as beam deflectors for layer-to-layer optical interconnection. The quality of the polymerized surface was characterized by atomic force microscope (AFM) which shows the root-mean-square (RMS) roughness is no greater than 5nm. The propagation and reflection loss of the fabricated waveguide at wavelength of 850nm are estimated to be <ldB/cm and <1.5dB per reflection, respectively. Based on this result, the total layer-to-layer insertion loss was estimated to be less than 4dB/cm, demonstrating the great potential for optical interconnections on printed circuit boards (PCBs).