When uncorrected, metalenses exhibit significant chromatic dispersion that limits them to narrowband operation. To address this, several metalens singlets corrected for chromatic aberration recently have been demonstrated. These metalenses mainly rely on engineered metaatom dispersion, an approach that limits them to small diameter and NA. Here, we validate an alternative approach by experimentally demonstrating a metalens doublet that directs light along trajectories of appropriate length to produce the desired achromatic behavior. Our lens is corrected over the 800-900 nm spectral region, collects light incident over a 2 sq. mm area, and has an NA of 0.2.
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