Université de Neuchâtel

High-efficiency continuous surface-relief gratings for two-dimensional array generation

Ehbets, Peter ; Herzig, Hans-Peter ; Prongué, Damien ; Gale, M. T.

In: Optics Letters, 1992, vol. 17, no. 13, p. 908-910

Continuous surface-relief phase for two-dimensional (2-D) array generation have been realized by laser-beam writing lithography. For a 9 x 9 fan-out element, a diffraction efficiency of 94% and a uniformity of better than 8% have been achieved. These are, to our knowledge, the best published results for 2-D surface-relief fan-out elements. Separable and nonseparable solutions for the design of...

Université de Neuchâtel

Diffractive structures for testing nano-meter technology

Blattner, Peter ; Naqvi, S. S. H. ; Herzig, Hans-Peter ; Ehbets, Peter

In: Microelectronic Engineering, 1995, vol. 27, no. 1-4, p. 543-546

We investigated two optical methods for characterizing submicron structures. Average errors of a few nanometers can be determined by the far-field diffraction metrology utilizing diffractive structures having enhanced sensitivity to fabrication errors. The scanning spot metrology is well suited for analyzing lithographic masks.

Université de Neuchâtel

Improvements in diffraction efficiency of gratings and microlenses with continuous relief structures

Kuittinen, Markku ; Herzig, Hans-Peter ; Ehbets, Peter

In: Optics Communications, 1995, vol. 120, no. 5-6, p. 230-234

The fabrication of diffractive optical elements by laser-beam writing or gray-tone technology leads to continuous-relief phase elements. The diffraction efficiency of such elements is limited by the resolution of the process. In this paper, we compare the continuous-relief elements with the multilevel elements fabricated by binary technology. In particular, we will show that for similar sampling...

Université de Neuchâtel

TIR holography analyzed with coupled wave theory

Ehbets, Peter ; Herzig, Hans-Peter ; Dändliker, René

In: Optics Communications, 1992, vol. 89, no. 1, p. 5-11

A coupled wave model is presented to describe the diffraction behavior of thick total-internal reflection (TIR) holograms. We have transformed the coupled wave equations into a transfer matrix formalism, enabling a general treatment of the boundary conditions. The off-Bragg characteristics of TIR holograms is found to be completely different from normal volume holograms. The diffraction...

Université de Neuchâtel

Beam Shaping of High-power Laser Diode Arrays by Continuous Surface-relief Elements

Ehbets, Peter ; Herzig, Hans-Peter ; Dändliker, René ; Regnault, P. ; Kjelberg, I.

In: Journal of Modern Optics, 1993, vol. 40, no. 4, p. 637-645

A breadboard for beam shaping of high-power laser diode arrays (LDAs) has been realized. The coherent beams are added with the aid of a continuous surface-relief fan-in element. It results in a nearly symmetric single lobed beam of collimated light with maximum conversion efficiency. The theoretical efficiency is determined to be 96•7%. Experimentally, one third of the total power is now in the...

Université de Neuchâtel

Diffractive optical elements for space communication terminals

Herzig, Hans-Peter ; Ehbets, Peter ; Teijido, Juan M. ; Weible, Kenneth J. ; Heimbeck, Hans-Joerg

In: Space Optics 1994: Space Instrumentation and Spacecraft Optics (Proceedings of SPIE), 1994, vol. 2210, p. 104-111

The potential of diffractive optical elements for advanced laser communication terminals has been investigated. Applications include beam shaping of high- power laser diode arrays, optical filter elements for position detection and hybrid (refractive/diffractive) elements. In addition, we present a design example of a miniaturized terminal including diffractive optics.