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...

Liquid deformable mirror for high-order wavefront correction

We propose and demonstrate a novel liquid deformable mirror, based on electrocapillary actuation, for highorder wavefront correction. The device consists of a two-dimensional array of vertically oriented microchannels filled with two immiscible liquids, an aqueous electrolyte, and a viscous dielectric liquid, where the dielectric liquid...

Correcting movement errors in frequency-sweeping interferometry

Absolute distance measurements can be performed with an interferometric method that uses only a single tunable laser. This method has one major drawback, because a small target movement of the order of one wavelength during a measurement will be interpreted as a movement of one synthetic wavelength. This effect is usually mitigated by adding a...

Influence of virtual images on the signal-to-noise ratio in digital in-line particle holography

A theoretical analysis describing the dependence of the signal-tonoise ratio (SNR) on the number of pixels and the number of particles is presented for in-line digital particle holography. The validity of the theory is verified by means of numerical simulation. Based on the theory we present a practical performance benchmark for digital...