Abstract-Miniature chiral beamsplitter based on gyroid photonic crystals

                                                            The CBS is built from a cubic chiral srs-network and
                                                            with the ability to split circularly polarized light.

Mark D. Turner, Matthias Saba, Qiming Zhang, Benjamin P. Cumming,Gerd E. Schröder-Turk, Min Gu,
http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2013.233.html
The linearly polarizing beamsplitter^{1, 2} is a widely used optical component in photonics. It is typically built from a linearly birefringent crystal such as calcite, which has different critical reflection angles for s- and p-polarized light³, leading to the transmission of one linear polarization and angled reflection of the other. However, the analogue for splitting circularly polarized light has yet to be demonstrated due to a lack of natural materials with sufficient circular birefringence. Here, we present a nano-engineered photonic-crystal chiral beamsplitter that fulfils this task. It consists of a prism featuring a nanoscale chiral gyroid network^{4, 5, 6, 7, 8, 9, 10} and can separate left- and right-handed circularly polarized light in the wavelength region around 1.615 µm. The structure is fabricated using a galvo-dithered direct laser writing method and could become a useful component for developing integrated photonic circuits that provide a new form of polarization control.