Design of a complex filter for depth of focus extension

Frédéric Diaz (1, 2) , François Goudail (2) , Brigitte Loiseau (1) , Jean-Pierre Huignard (1)

1 Thales Research and Technology [Palaiseau]
2 Laboratoire Charles Fabry de l'Institut d'Optique / Scop

Different methods such as axilens and binary-phase filter have been investigated to improve the depth of focus. A method is proposed to calculate an amplitude-phase pupil filter and obtain the desired distribution of intensity along the optical axis. It produces a narrow spot with a uniform intensity level over a large depth of focus, comparable to the performance obtainable with binary-phase filters. This filter is of particular interest for applications where very low intensity fluctuations along the focus range are required.

Domains: Physics [physics]; Physics [physics]; Optics [physics.optics]

Frédéric Diaz, François Goudail, Brigitte Loiseau, Jean-Pierre Huignard. Design of a complex filter for depth of focus extension. Optics Letters, 2009, 34 (8), pp.1171-1173. ⟨hal-00746928⟩