Fabrication of ordered mesoporous thin films for optical waveguiding and interferometric chemical sensing

Planar optical waveguides with a propagation loss of 2.9 dB/cm at 633 nm were fabricated using ordered mesoporous thin films of TiO2-P2O5 nanocomposite deposited on the tin-rich surfaces of float glass slides. The resulting waveguides show substantial sensitivity to parts-per-million-level ammonia gas at room temperature on the basis of single-beam polarimetric interferometry.