Strontium Niobate for Near‐Infrared Plasmonics

Plasmonics has developed greatly over the past two decades, and a plethora of plasmonic materials has been explored for practical plasmonic devices across various applications. While noble metals such as gold and silver are the most widely used plasmonic materials, other metals such as aluminum, copper, and magnesium have also been proposed as building blocks for plasmonics. Transparent conducting oxides (TCOs) such as aluminum‐ and gallium‐doped zinc oxide and tin‐doped indium oxide have been suggested for plasmonic applications in the near infrared (NIR) spectrum. These materials have lower carrier concentration than noble metals and therefore have lower material losses at the NIR. In this paper, strontium niobate (SNO) is showcased as an addition to the material database for plasmonics in the NIR. SNO plasmonic properties are studied through experimental demonstration of hybrid plasmon resonances in SNO films. Such resonances are characterized by electromagnetic field concentration in a low‐index dielectric, sandwiched between a high‐index dielectric resonator and a plasmonic metal. The results show that although SNO bulk film has an order of magnitude greater carrier concentration than TCOs, its losses are only a few times higher than in TCO materials thus holding a promise for plasmonic applications in the NIR.