The 4f optical configuration is a foundational and versatile arrangement in optical system design, serving as the cornerstone for numerous modern optical instruments across industries.

This e-book traces the 4f system’s evolution, from its origins in Fourier optics to its role in modern microscopy, laser systems, telecommunications, and adaptive optics. We’ve examined both refractive and reflective implementations, addressing critical design considerations including aberration control, spectral performance, and the interplay between pupil and image planes.