We report on generating a magneto-optical trap (MOT) of 88-strontium (${}^{88}$$\mathrm{Sr}$) atoms at microkelvin temperature, using integrated-photonics devices. With metasurface optics integrated on a fused-silica substrate, we generate six-beam circularly polarized counterpropagating MOTs on the blue broad-line (461-nm) and red narrow-line (689-nm) $\mathrm{Sr}$ cooling transitions without bulk optics. By use of a diverging beam configuration, we create up to 10-mm-diameter MOT beams at the trapping location. To frequency stabilize and linewidth narrow the cooling lasers, we use fiber-packaged integrated nonlinear waveguides to spectrally broaden a frequency comb. The ultracoherent supercontinuum of the waveguides covers 650–2500 nm, enabling phase locks of the cooling lasers to hertz-level linewidth. Our work highlights the possibility of simplifying the preparation of an ultracold ${}^{88}$$\mathrm{Sr}$ gas for an optical-lattice clock with photonic devices. By implementing a timing sequence for control of the MOT lasers and the quadrupole magnetic field gradient, we collect atoms directly from a thermal beam into the blue MOT and continuously cool into a red MOT with dynamic detuning and intensity control. There, the red-MOT temperature is as low as $2\text{μ}\mathrm{K}$ and the overall transfer efficiency is up to 16%. We characterize this sequence, including an intermediate red MOT with modulated detuning.

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• Atomic & molecular processes in external fields
• Atomic, optical & lattice clocks
• Cold atoms & matter waves
• Integrated optics
• Metasurfaces
• Nonlinear waveguides
• Spatial profiles of optical beams
• Spectral shaping
• Atomic gases
• Atom & ion cooling