Université de Neuchâtel

High Resolution Interference Microscopy: A Tool for Probing Optical Waves in the Far-Field on a Nanometric Length Scale

Rockstuhl, Carsten ; Märki, Iwan ; Scharf, Toralf ; Salt, Martin Guy ; Herzig, Hans-Peter ; Dändliker, René

In: Current Nanoscience, 2006, vol. 2, no. 4, p. 337-350

High Resolution Interference Microscopy (HRIM) is a technique that allows the characterization of amplitude and phase of electromagnetic wave-fields in the far-field with a spatial accuracy that corresponds to a few nanometers in the object plane. Emphasis is put on the precise determination of topological features in the wave-field, called phase singularities or vortices, which are spatial...

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

Optically tunable microcavity in a planar photonic crystal silicon waveguide buried in oxide

Märki, Iwan ; Salt, Martin Guy ; Herzig, Hans-Peter ; Stanley, Ross ; Melhaoui, L. El. ; Lyan, P. ; Fedeli, J. M.

In: Optics Letters, 2006, vol. 31, no. 4, p. 513-515

We present all-optical tuning and switching of a microcavity inside a two-dimensional photonic crystal waveguide. The photonic crystal structure is fabricated in silicon-on-insulator using complementary metal-oxide semiconductor processing techniques based on deep ultraviolet lithography and is completely buried in a silicon dioxide cladding that provides protection from the environment. By...

Université de Neuchâtel

Tuning the resonance of a photonic crystal microcavity with an AFM probe

Märki, Iwan ; Salt, Martin Guy ; Herzig, Hans-Peter

In: Optics Express, 2006, vol. 14, no. 7, p. 2969-2978

We present theoretical and experimental results on switching and tuning of a two-dimensional photonic crystal resonant microcavity by means of a silicon AFM tip, probing the highly localized optical field in the vicinity of the cavity. On-off switching and modulation of the transmission signal in the kHz range is achieved by bringing an AFM tip onto the center of the microcavity, inducing a...

Université de Neuchâtel

Application of the boundary-element method to the interaction of light with single and coupled metallic nanoparticles

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

In: Journal of the Optical Society of America A, 2003, vol. 20, no. 10, p. 1969-1973

The boundary-element method is applied to the interaction of light with resonant metallic nanoparticles. At a certain wavelength, excitation of a surface plasmon takes place, which leads to a resonantly enhanced near-field amplitude and a large scattering cross section. The resonance wavelength for different scatterer geometries is determined. Alteration of the scattering properties in 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

Analyzing the scattering properties of coupled metallic nanoparticles

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

In: Journal of the Optical Society of America A, 2004, vol. 21, no. 9, p. 1761-1768

We apply the boundary element method to the analysis of the plasmon response of systems that consist of coupled metallic nanoscatterers. For systems made of two or more objects, the response depends strongly on the individual particle behavior as well as on the separation distance and on the configuration of the particles relative to the illumination direction. By analyzing the behavior of these...

Université de Neuchâtel

Practical and theoretical modal analysis of photonic crystal waveguides

Märki, Iwan ; Salt, Martin Guy ; Herzig, Hans-Peter

In: Journal of Applied Physics, 2004, vol. 96, no. 1, p. 7-11

We present practical and theoretical, stage-by-stage analysis of light propagation around a 90° corner in a two-dimensional photonic crystal waveguide. Using a series of different samples we quantify the coupling efficiency between the conventional ridge waveguide and the photonic crystal waveguide as well as the bending efficiency around the 90° corner. From this, the transmission spectra...

Université de Neuchâtel

Characterization of photonic crystal waveguides based on Fabry-Pérot interference

Märki, Iwan ; Salt, Martin Guy ; Stanley, Ross ; Staufer, Urs ; Herzig, Hans-Peter

In: Journal of Applied Physics, 2004, vol. 96, no. 12, p. 6966-6969

We present two methods based on the analysis of Fabry-Pérot interference for a detailed characterization of a 90° corner in a two-dimensional photonic crystal waveguide fabricated in a thin Si membrane. These methods are a means of identifying the critical waveguide elements in the process of improving photonic crystal devices. The effects of the elements forming the photonic crystal waveguide...

Université de Neuchâtel

Characterization of buried photonic crystal waveguides and microcavities fabricated by deep ultraviolet lithography

Märki, Iwan ; Salt, Martin Guy ; Herzig, Hans-Peter ; Stanley, Ross ; El Melhaoui, L. ; Lyan, P. ; Fedeli, J. M.

In: Applied Physics Letters, 2005, vol. 98, no. 013103, p. 1-4

We present results of the optical characterization of silicon photonic crystal waveguides and microcavities that are completely buried in a silicon dioxide cladding and are fabricated by deep ultraviolet (UV) lithography. The advantages of buried waveguides and deep UV lithography are discussed. Transmission spectra and loss factors for photonic crystal waveguides, as well as quality factors for...