|| Low Q of ring-resonators in vacuum
|| 1) Use more power; 2) Post-fab annealing; 3) Process improvement.
|| Sample heating (by laser) and temperature instability
|| Use cooled and temperature regulated sample stage. Reduce laser power fluctuations with feedback.
|| Insufficient circulating trap power
|| PIC annealing. SLM/DMD-based incoupling enhancement. Slave lasers.
|| Weak absorption signal
|| Add intercombination cooling. Apply AC noise rejection techniques.
|| Insufficient number of trapped atoms
|| Increase load time. SWAP cooling in red MOT. Narrower 689 beams. Geometrically brightened SrO source. Additional free-space transparency beam.
|| Weak fluorescence signal
|| EMCCD detection. MOT re-capture. High-NA optics.
|| Imbalanced splitting
|| Tune Bragg pulse parameters.
|| Low-contrast interference
|| Stabilize trap intensity. Use full integer cycles. Smaller loops with more cycles.
|| PIC degradation over time
|| Repeated device annealing at high temperature ($>$1500C) to suppress defects and drifting mechanisms
|| PIC drift due to atomic adsorption
|| Substrate heating. Light-induced desorption.
|| Interaction of trapped atoms with adsorbates
|| Annealing. Substrate heating. Light-induced desorption.
|| Insufficient brightness of SrO atom source
|| Vary desorption power and wavelength. Vary SrO geometry and distance.
|| Atom loss from ring inhomogeneities
|| Vary relative trapping beam power. PIC annealing. Feed back to fabrication steps.
|| Ring potential inhomogeneity at waveguide coupler
|| Use modeling and observations as feedback to fabrication.
|| Back-scattering breaking CW/CCW symmetry, trap modulation due to partial standing waves
|| Reduce considered 200~$\mu$K trap depths to 10-$\mu$K, tune trapping wavelengths.