Using a dual chopping scheme where both the pump beam and the probe beam are chopped, we show that it is possible to perform photoreflectance spectroscopy with a broadband white light source as the pump beam instead of a laser source. We show that although the signal strength is reduced by a factor of 1/p in the dual chopping scheme, it nevertheless has several advantages. A white light pump be...

Beams with helical phasefronts described by exp(ilphi) carry an orbital angular momentum equivalent to lh per photon. Using diffractive optics this helical phase structure can be applied to every spectral component of the beam such that a spatially coherent white-light beam can carry orbital angular momentum without any chromatic distortion. This achromatic property can be hard to achieve in sp...

Projections of the atomic structure around Nb atoms in a LiNbO(3) single crystal were obtained from a white-beam X-ray absorption anisotropy (XAA) pattern detected using Nb K fluorescence. This kind of anisotropy results from the interference of X-rays inside a sample and, owing to the short coherence length of a white beam, is visible only at small angles around interatomic directions. Consequ...

Several possibilities are investigated to control spatio-temporal characteristics of the femtosecond filamentation process and the resulting white-light generation. We controlled the development of self-focusing, and resulting locations of filaments producing white-light in water by changing the transverse spatial phase of an initial Gaussian beam with a computer generated holographic technique...

Interferometer Setup The Twyman–Green interferometer (Figure 1) is a special configuration of the well-known Michelson interferometer with optics that superimpose the images of the object and the reference planes. Polytec engineers use this interferometer and place a CCD image sensor like those used for digital photography at the point where the two images are superimposed. A broadband “white-l...