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The combination of photonic integrated circuits and free-space metaoptics has the ability to untie technological knots that require advanced light manipulation due to their conjoined ability to achieve strong light–matter interaction via wave-guiding light over a long distance and shape them via large space-bandwidth product. Rapid prototyping of such a compound system requires component interchangeability. This represents a functional challenge in terms of fabrication and alignment of high-performance optical systems. Here, we report a flexible and interchangeable interface between a photonic integrated circuit and the free space using an array of low-loss metaoptics and demonstrate multifunctional beam shaping at a wavelength of 780 nm. We show that robust and high-fidelity operation of the designed optical functions can be achieved without prior precise characterization of the free-space input nor stringent alignment between the photonic integrated chip and the metaoptics chip. A diffraction limited spot of ∼3 μm for a hyperboloid metalens of numerical aperture 0.15 is achieved despite an input Gaussian elliptical deformation of up to 35% and misalignments of the components of up to 20 μm. A holographic image with a peak signal-to-noise ratio of >10 dB is also reported. 

Establishing a coherent interaction between a material resonance and an optical cavity is a necessary first step to study semiconductor quantum optics. Here we report on the signature of a coherent interaction between a two-dimensional excitonic transition in monolayer MoSe₂and a zero-dimensional, ultra-low mode volume (V_m ∼ 2(λ/n)³) on-chip photonic crystal nanocavity. This coherent interaction manifests as a dispersive shift of the cavity transmission spectrum, when the exciton-cavity detuning is decreased via temperature tuning. The exciton-cavity coupling is estimated to be ≈6.5 meV, with a cooperativity of ≈4.0 at 80 K, showing our material system is on the verge of strong coupling. The small mode-volume of the resonator is instrumental in reaching the strongly nonlinear regime, while on-chip cavities will help create a scalable quantum photonic platform.