Etching-Free Rare-Earth-Doped Al₂O₃ and Y₂O₃ Micro-Devices Made by Pulsed Laser Deposition and Lift-Off

The realization of rare-earth-doped integrated optical devices is crucial for the making of amplifiers, lasers on chip and quantum photonics. [1], [2] Rare-earth-doped yttria and alumina materials are highly promising for such application thanks to their high solubility of rare-earth ions and their excellent transparency in visible and infrared.[3], [4] However, structuring and integration remain particularly challenging for chemically and mechanically robust materials like alumina or yttria. [5] For such materials, etching-based processes are challenging, costly and degrade performance.[6] In this paper, we present an innovative etching-free process based on Pulsed Laser Deposition (PLD) and lift-off for the fabrication of rare-earth doped waveguides, rings and photonic crystals.