Monolithically integrated isolators based on nanowire-grid polarizers

We developed a free-space monolithically integrated semi-isolator based on a new type of wire-grid polarizer, nanowire-grid polarizer. The nanowire-grid polarizer, which has an active structure with a total thickness of about 1 μm, was fabricated directly onto a Faraday magnetooptic rotator by nanofabrication processes. Full free-space isolators based on the integrated semi-isolators were assembled which achieved very low insertion loss (/spl sim/0.2 dB) and high isolation (/spl sim/35 dB). The integrated semi-isolator enables fabrication of the full isolator more efficient and, furthermore, it allows a smaller footprint which is crucial for applications requiring a compact footprint.