Space-Variant Quarter- And Half-Wave Plates Fabricated By Combining 3d Laser Direct Writing And Electroplating

In this contribution, we present the fabrication of space-variant quarter- and half-wave plates, by combining 3D laser direct writing with electroplating. A negative of the space-variant wave plates was fabricated with 3D laser direct writing in a positive tone photoresist. With an electrochemical deposition process the negative structure of the wave plates was filled with gold. This process allows fabrication of a non-quadratic air filled cross-section surrounded by a metallic cladding, a so-called hollow waveguide array. The wave plates consists of about 1000 x 1500 hollow waveguides each with sub-wavelength dimensions for an operating wavelength of 1550 nm.