Université de Neuchâtel

Review of iterative Fourier-transform algorithms for beam shaping applications

Ripoll, Olivier ; Kettunen, Ville ; Herzig, Hans-Peter

In: Optical Engineering, 2004, vol. 43, no. 11, p. 2549

We present a comparison of some of the most used iterative Fourier transform algorithms (IFTA) for the design of continuous and multilevel diffractive optical elements (DOE). Our aim is to provide optical engineers with advice for choosing the most suited algorithm with respect to the task. We tackle mainly the beam-shaping and the beam-splitting problems, where the desired light distributions...

Université de Neuchâtel

Diffractive elements designed to suppress unwanted zeroth order due to surface depth error

Kettunen, Ville ; Jefimovs, Konstantins ; Simonen, Janne ; Ripoll, Olivier ; Kuittinen, Markku ; Herzig, Hans-Peter

In: Journal of Modern Optics, 2004, vol. 51, no. 14, p. 2111-2123

We consider a design approach to reduce unwanted zero-order intensity due to profile depth error in diffractive elements. Our method is based on addition of local bias phase to a binary element phase, leading to the introduction of a third phase level. We show theoretically and experimentally that gratings obtained with such modifications are more tolerant to profile depth error than...

Université de Neuchâtel

Low-data simulation of diffractive optical elements based on the zones geometry

Ripoll, Olivier ; Kettunen, Ville ; Herzig, Hans-Peter

In: Journal of Modern Optics, 2002, vol. 49, no. 11, p. 1801-1809

Design and simulation of two-dimensional diffractive optical elements are often limited by the amount of data required to represent the element in the computer's memory. We present a technique based on a geometrical description of the element, which requires fewer data than the traditional pixel description. Moreover, the element is being described more accurately and consequently the...

Université de Neuchâtel

Beam shaping in deep UV: comparison of methods

Kettunen, Ville ; Ripoll, Olivier ; Herzig, Hans-Peter

In: Diffractive Optics (Topical Meetings Digest Series), 2001, vol. 30, p. 80-81

Université de Neuchâtel

Low-data DOE simulation based on the zones geometry

Ripoll, Olivier ; Herzig, Hans-Peter ; Kettunen Ville

In: Diffractive Optics (Topical Meetings Digest Series), 2001, vol. 30, p. 78-79