Nano-mechanical tuning and imaging of a photonic crystal micro-cavity resonance

We show that nano-mechanical interaction using atomic force microscopy (AFM) can be used to map out mode-patterns of an optical micro-resonator with high spatial accuracy. Furthermore we demonstrate how the Q-factor and center wavelength of such resonances can be sensitively modified by both horizontal and vertical displacement of an AFM tip consisting of either Si3N4 or Si material. With a silicon tip we are able to tune the resonance wavelength by 2.3 nm, and to set Q between values of 615 and zero, by expedient positioning of the AFM tip. We find full on/off switching for less than 100 nm vertical, and for 500 nm lateral\ud displacement at the strongest resonance antinode locations

Interactions with a photonic crystal micro-cavity using AFM in contact or tapping mode operation

In this paper we show how the evanescent field of a localized mode in a photonic crystal micro-cavity can be perturbed by a nano-sized AFM tip. Due to the high field intensities in the cavity, we can see a significant change in output power when the tip is brought into the evanescent field in either contact or tapping mode operation. We find a 4 dB modulation, when using a $Si_{3}N_{4}$ tip and we show that the transmittance can be tuned from 0.32 to 0.8 by varying the average tapping height

Nano-mechanical tuning and imaging of a photonic crystal micro-cavity resonance

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Modeling of chemical processes in the low pressure capacitive RF discharges in a mixture of Ar/C2H2

We study the properties of a capacitive 13.56 MHz discharge properties with a mixture of Ar/C2H2 taking into account the plasmochemistry and growth of heavy hydrocarbons. A hybrid model was developed to combine the kinetic description for electron motion and the fluid approach for negative and positive ions transport and plasmochemical processes. A significant change of plasma parameters related to injection of 5.8% portion of acetylene in argon was observed and analyzed. We found that the electronegativity of the mixture is about 30%. The densities of negatively and positively charged heavy hydrocarbons are sufficiently large to be precursors for the formation of nanoparticles in the discharge volume.Comment: 11 pages, 14 figure

Unraveling the deposition mechanism in a-C:H thin-film growth : a molecular-dynamics study for the reaction behavior of C3 and C3H radicals with a-C:H surfaces

In this mol.-dynamics study, we present the simulated growth of thin a-C:H films using the Brenner [Phys. Rev. B 42, 9458 (1990)] potential. These simulations are relevant for the growth of thin films, grown using low-energy hydrocarbons. In this work, we investigate the reaction mechanisms of both the linear and the cyclic isomers of C3 and C3H on an a-C:H surface. We found that the cyclic species are always more reactive as compared to the linear species, due to their lower stability. The C3 species are found to be more reactive than the C3H species, due to steric hindrance of the H atom, shielding the C atom from the surface. The different mechanisms are discussed. The resulting film properties for different flux ratios of C3 and C3H have also been investigated. It is shown that films as deposited from C3 and C3H have a low d. and show low crosslinking. A clear change in microstructure is obsd. as the ratio between the cyclic and the linear species changes. These simulations provide insights into the reaction behavior of the investigated species, and how this influences the resulting film properties. [on SciFinder (R)

Photonics and electronics integration in the HELIOS project

The objective of the European project HELIOS is to combine a photonic layer with a CMOS circuit by different innovative means, using microelectronics processes. Bonding of AWG + Ge Photodiodes on CMOS wafer is achieved