Near-infrared transparent electrodes for precision Teng-Man electro-optic measurements: In_2O_3 thin-film electrodes with tunable near-infrared transparency

摘要

Highly near-infrared (NIR) transparent In_2O_3 thin films have been grown by ion-assisted deposition at room temperature, and the optical and electrical properties characterized. NIR transparency and the plasma edge frequency can be engineered by control of the film deposition conditions. As-deposited In_2O_3 thin films were employed as transparent electrodes for direct thin film electro-optic (EO) characterization measurements via the Teng—Man technique. Using LiNbO_3 as the standard, the relationship between electrode NIR transparency and Teng-Man EO measurement accuracy was evaluated. It is found that In_2O_3 electrodes can be tailored to be highly NIR transparent, thus providing far more accurate Teng-Man EO coefficient quantification than tin-doped indium oxide. In addition, the EO coefficients of stilbazolium-based self-assembled superlattice thin films were directly determined for the first time using an optimized In_2O_3 electrode. EO coefficients r_(33) of 42.2, 13.1, and 6.4 pm/V are obtained at 633, 1064, and 1310 nm, respectively.