Probing the Limits of Optical Loss in Ion-Sliced Thin-film Lithium Niobate

We measured the absorption-limited loss at telecommunication wavelengths for thin-film lithium niobate micro-ring resonators using Kerr-calibrated linear response technique. We find the average absorption loss-rate κabs/2π to be 3.65 ± 0.70 MHz, corresponding to a Q-factor of 55 Million.