UV integrated photonics in sputter deposited aluminum oxide

Ultraviolet operating photonic integrated circuits (UV-PICs) can have large impact in application fields including UV Raman spectroscopy, UV-VIS spectroscopy, microscopy, metrology and quantum technology. In this work, we introduce a polycrystalline Al2O3 integrated photonic platform exhibiting ultra broadband operation from the ultraviolet (~200 nm) till the mid-IR (~3 um) with very low propagation losses (i.e., 1.3 dB/cm at 369 nm of wavelength for TM polarization). Propagation loss characterization of channel waveguides with different widths revealed sidewall roughness as major contributor to the losses, paving the way for further future optimization of the devices.