Demonstration of spot size reduction by focussing amplitude modulated radially polarized light on a photoresist

Spot size reduction is demonstrated by printing focused spots from amplitude-modulated radially polarized light at the wavelength ? = 405 nm on a photoresist. Amplitude modulation is realized by ring illumination and by application of an optimized amplitude distribution function. Amplitude modulation is implemented via spatial light modulator,...

Radially Polarized Light for Detection and Nanolocalization of Dielectric Particles on a Planar Substrate

A fast noninvasive method based on scattering from a focused radially polarized light to detect and localize subwavelength nanoparticles on a substrate is presented. The technique relies on polarization matching in the far field between scattered and spurious reflected fields. Results show a localization uncertainty of ?10?4?2 is possible for a...

Long distance measurement with femtosecond pulses using a dispersive interferometer

We experimentally demonstrate long distance measurements with a femtosecond frequency comb laser using dispersive interferometry. The distance is derived from the unwrapped spectral phase of the dispersed interferometer output and the repetition frequency of the laser. For an interferometer length of 50 m this approach has been compared to an...

Time-frequency distribution of interferograms from a frequency comb in dispersive media

We investigate general properties of the interferograms from a frequency comb laser in a non-linear dispersive medium. The focus is on interferograms at large delay distances and in particular on their broadening, the fringe formation and shape. It is observed that at large delay distances the interferograms spread linearly and that its shape is...

From a discrete to a continuous model for interpulse interference with a frequency-comb laser

We have investigated correlation patterns generated by a frequency-comb laser in a dispersive unbalanced Michelson interferometer and apply the developed formalism to the case of distance metrology. Due to group velocity dispersion, the position of the brightest fringe of the correlation pattern, which is used for distance determination, cannot...

High-accuracy long-distance measurements in air with a frequency comb laser

We experimentally demonstrate that a femtosecond frequency comb laser can be applied as a tool for longdistance measurement in air. Our method is based on the measurement of cross correlation between individual pulses in a Michelson interferometer. From the position of the correlation functions, distances of up to 50 m have been measured. We...