A new approach to multiwavelength achromatic metasurfaces is presented, which overcomes the chromatic aberrations inherent in refractive and diffractive optics. By using engineered wavelength-dependent phase shifts, the metasurface deflects three wavelengths without dispersion, and a planar lens without chromatic aberrations at three wavelengths is also demonstrated. The design is based on low-loss dielectric resonators that introduce a dense spectrum of optical modes to enable dispersive phase compensation. This approach suppresses chromatic aberrations in metasurface-based planar photonics, finding applications in lightweight collimators for displays and chromatically-corrected imaging systems. Refractive and diffractive optical components behave differently when manipulating broadband light. Refractive lenses have larger focal distances for red light than for blue light, while diffractive lenses and gratings exhibit the opposite behavior. This difference arises from the different principles used to shape light: refractive optics rely on phase accumulation, while diffractive optics use interference. In refractive lenses, chromatic aberrations occur due to the wavelength dependence of the focal length, while diffractive optics suffer from strong chromatic aberrations due to the presence of higher diffraction orders. Metasurfaces are thin optical components that use a different approach for light control: a dense arrangement of subwavelength resonators is designed to modify the optical response of the interface. The resonant nature of the scatterers introduces an abrupt phase shift in the incident wavefront, enabling a new class of planar photonics components. The metasurface approach provides continuous control of the phase profile with a binary structure, circumventing the fundamental limitation of multiple diffraction orders while maintaining the size, weight, and ease-of-fabrication advantages of planar diffractive optics. The design of an achromatic metasurface involves a subwavelength size resonator that adjusts the scattered phase at different wavelengths to satisfy a specific condition. In this work, coupled rectangular dielectric resonators are used as building blocks. The metasurface is designed to deflect normally incident light at an angle of -17 degrees for three different wavelengths. The design is validated through simulations and experiments, showing that the metasurface achieves achromatic behavior at multiple wavelengths. The performance of an achromatic flat lens based on RDRs is also presented. This device is functionally equivalent to a bulk refractive lens known as an apochromatic triplet. The lens is designed to focus light at three wavelengths without chromatic aberrations, achieving focusing close to the diffraction limit. The results suggest a viable path toward the creation of a truly broadband metasurface that can suppress chromatic aberrations for a high number of wavelengths with a reduced number of components compared to refractive optics.A new approach to multiwavelength achromatic metasurfaces is presented, which overcomes the chromatic aberrations inherent in refractive and diffractive optics. By using engineered wavelength-dependent phase shifts, the metasurface deflects three wavelengths without dispersion, and a planar lens without chromatic aberrations at three wavelengths is also demonstrated. The design is based on low-loss dielectric resonators that introduce a dense spectrum of optical modes to enable dispersive phase compensation. This approach suppresses chromatic aberrations in metasurface-based planar photonics, finding applications in lightweight collimators for displays and chromatically-corrected imaging systems. Refractive and diffractive optical components behave differently when manipulating broadband light. Refractive lenses have larger focal distances for red light than for blue light, while diffractive lenses and gratings exhibit the opposite behavior. This difference arises from the different principles used to shape light: refractive optics rely on phase accumulation, while diffractive optics use interference. In refractive lenses, chromatic aberrations occur due to the wavelength dependence of the focal length, while diffractive optics suffer from strong chromatic aberrations due to the presence of higher diffraction orders. Metasurfaces are thin optical components that use a different approach for light control: a dense arrangement of subwavelength resonators is designed to modify the optical response of the interface. The resonant nature of the scatterers introduces an abrupt phase shift in the incident wavefront, enabling a new class of planar photonics components. The metasurface approach provides continuous control of the phase profile with a binary structure, circumventing the fundamental limitation of multiple diffraction orders while maintaining the size, weight, and ease-of-fabrication advantages of planar diffractive optics. The design of an achromatic metasurface involves a subwavelength size resonator that adjusts the scattered phase at different wavelengths to satisfy a specific condition. In this work, coupled rectangular dielectric resonators are used as building blocks. The metasurface is designed to deflect normally incident light at an angle of -17 degrees for three different wavelengths. The design is validated through simulations and experiments, showing that the metasurface achieves achromatic behavior at multiple wavelengths. The performance of an achromatic flat lens based on RDRs is also presented. This device is functionally equivalent to a bulk refractive lens known as an apochromatic triplet. The lens is designed to focus light at three wavelengths without chromatic aberrations, achieving focusing close to the diffraction limit. The results suggest a viable path toward the creation of a truly broadband metasurface that can suppress chromatic aberrations for a high number of wavelengths with a reduced number of components compared to refractive optics.