US Patent 7230760 Polarizers and isolators and methods of manufacture

A passively aligned optical isolator includes laminated layers of material including two polarizing glass layers sandwiching a Faraday rotator layer. Each polarizing glass layer comprises a glass matrix containing elongated metal particles exhibiting a change in polarization axis of less than about 0.0375°/m over a distance of at least 8 mm, as measured across a major surface of the layer. The optical isolator has a contrast ratio greater than 40 dB.