I can only think of picometres, but it doesn't seem to make sense. Here is the context, from this paper:

Our results suggest that consistently high performance temperature sensors are obtained from the zone of stability (waveguide width > 600 nm, air gap ≈ 130 nm and ring radius >10 µm) such that quality factors are consistent ≈ 10⁴ and the temperature sensitivity is in the 70 pm/K to 80 pm/K range.

I can only think of picometres, but it doesn't seem to make sense. Here is the context, from the paper 'Towards Reproducible Ring Resonator Based Temperature Sensors', Klimov et al., Sensors & Transducers 191, 63 (2015):

Our results suggest that consistently high performance temperature sensors are obtained from the zone of stability (waveguide width > 600 nm, air gap ≈ 130 nm and ring radius >10 µm) such that quality factors are consistent ≈ 10⁴ and the temperature sensitivity is in the 70 pm/K to 80 pm/K range.

I can only think of picometres, but it doesn't seem to make sense. Here is the context, from this paper:

Our results suggest that consistently high performance temperature sensors are obtained from the zone of stability (waveguide width > 600 nm, air gap » 130 nm and ring radius >10 µm) such that quality factors are consistent » 104 and the temperature sensitivity is in the 70 pm/K to 80 pm/K range.

I can only think of picometres, but it doesn't seem to make sense. Here is the context, from this paper:

Our results suggest that consistently high performance temperature sensors are obtained from the zone of stability (waveguide width > 600 nm, air gap ≈ 130 nm and ring radius >10 µm) such that quality factors are consistent ≈ 10⁴ and the temperature sensitivity is in the 70 pm/K to 80 pm/K range.