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Université de Neuchâtel

Observation of amplitude and phase in ridge and photonic crystal waveguides operating at 1.55 μm by use of heterodyne scanning near-field optical microscopy

Tortora, Pierpasquale ; Abashin, M. ; Märki, Iwan ; Nakagawa, Wataru ; Vaccaro, Luciana ; Salt, Martin Guy ; Herzig, Hans-Peter ; Levy, U. ; Fainman, Y.

In: Optics Letters, 2005, vol. 30, no. 21, p. 2885-2887

We apply heterodyne scanning near-field optical microscopy (SNOM) to observe with subwavelength resolution the amplitude and phase of optical fields propagating in several microfabricated waveguide devices operating around the 1.55 μm wavelength. Good agreement between the SNOM measurements and predicted optical mode propagation characteristics in standard ridge waveguides demonstrates the...

Université de Neuchâtel

Phase function encoding of diffractive structures

Schilling, Andreas ; Herzig, Hans-Peter

In: Applied Optics, 2000, vol. 39, no. 29, p. 5273-5279

We analyzed the direct sampling (DS) method for diffractive lens encoding, using exact electromagnetic diffraction theory. In addition to previously published research [Pure Appl. Opt. 7, 565 (1998)] we present what we believe to be new results for TM polarization. We found that the validity of the scalar-based DS method is even more extended for TM than for TE polarization. Additionally, we...

Université de Neuchâtel

Calculation of the torque on dielectric elliptical cylinders

Rockstuhl, Carsten ; Herzig, Hans-Peter

In: Journal of the Optical Society of America A, 2005, vol. 22, no. 1, p. 109-116

We present our investigation of the torque exerted on dielectric elliptical cylinders by highly focused laser beams. The calculations are performed with rigorous diffraction theory, and the size-dependent torque is analyzed as a function of the axis ratio. It is found that highly elongated particles will experience a reversal of the torque for a radius that is approximately one third of the...

Université de Neuchâtel

Analysis of the phonon-polariton response of silicon carbide microparticles and nanoparticles by use of the boundary element method

Rockstuhl, Carsten ; Salt, Martin Guy ; Herzig, Hans-Peter

In: Journal of the Optical Society of America B, 2005, vol. 22, no. 2, p. 481-487

We investigate the small-particle phonon-polariton response of several microstructures that are made of silicon carbide (SiC). Phonon polaritons can be excited in a wavelength region between 10 and 12 µm. Simple structures such as elliptical cylinders support phonon polaritons at two wavelengths, which depend on the axis ratio of the particle. In particles with a more irregular shape such as...

Université de Neuchâtel

On the chromatic aberration of microlenses

Ruffieux, Patrick ; Scharf, Toralf ; Herzig, Hans-Peter ; Völkel, Reinhard ; Weible, Kenneth J.

In: Optics Express, 2006, vol. 14, no. 11, p. 4687-4694

The optical properties of plano-convex refractive microlenses with low Fresnel Number (typically FN < 10) are investigated. It turns out that diffraction effects at the lens aperture limit the range of the effective focal length. The upper limit of the focal length is determined by the diffraction pattern of a pinhole with equal diameter. In addition achromatic microlenses can be realized because...

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

Holographic optical elements (HOE) for semiconductor lasers

Herzig, Hans-Peter

In: Optics Communications, 1986, vol. 58, no. 3, p. 144-148

A two step method is described to produce off-axis holographic lenses with high diffraction efficiency and without astigmatism for semiconductor lasers. The hologram is recorded in the visible (514 nm) and reconstructed in the infrared (800 nm). The principal parameters (recording and reconstruction angles, astigmatic focal lengths) for each hologram and wavelength are calculated analytically...

Université de Neuchâtel

Rigorous diffraction theory applied to microlenses

Blattner, Peter ; Herzig, Hans-Peter

In: Journal of Modern Optics, 1998, vol. 45, no. 7, p. 1395-1403

In this paper, we discuss the behaviour of small cylindrical microlenses, arranged in one-dimensional arrays and as single elements. For this purpose, we apply a standard rigorous diffraction theory, commonly used for diffraction gratings. We investigate the coupling effect between the elements. It turns out that single elements behave like periodic elements if the spacing is chosen correctly....

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.

Université de Neuchâtel

Continuous-relief fan-out elements with optimized fabrication tolerances

Ehbets, Peter ; Rossi, Markus ; Herzig, Hans-Peter

In: Optical Engineering, 1995, vol. 34, no. 12, p. 3456-3464

The design of kinoform fan-out elements with high efficiency and reduced sensitivity to vertical profile scaling errors is presented. We start from a high-efficiency continuous-phase fan-out solution and optimize the position of the 0-2π transitions in the phase function, in order to achieve a high fabrication-error tolerance. The sensitivity of Fourier-transform and focusing fan-out elements to...