Low-loss integrated photonics for the blue and ultraviolet regime

Understand

We present a low-loss integrated photonics platform in the visible and near ultraviolet regime.

• Fully-etched waveguides based on atomic layer deposition (ALD) of aluminum oxide operate in a single transverse mode with $<$3 dB/cm propagation loss at a wavelength of 371 nm.
• Ring resonators with intrinsic quality factors exceeding 470,000 are demonstrated at 405 nm, and the thermo optic coefficient of ALD aluminum oxide is estimated to be $2.75\times10^{-5}$ [RIU/$^\circ$C].
• Absorption loss is sufficiently low to allow on-resonance operation with intra-cavity powers up to at least 12.5 mW, limited by available laser power.