Habitat fragmentation and habitat loss are causing many species to become locally extinct. The need to restore or conserve biodiversity has initiated plans in Europeöand, more specifically, in the Netherlandsöto create networks of nature areas for the improvement of spatial coherence. In this paper spatial coherence is measured by the total boundary length of all nature areas. Spatial optimizat...

High-speed, high-resolution optical coherence tomography (OCT) imaging of the human retina is demonstrated using a frequency-swept laser at 850 nm. A compact external cavity semiconductor laser design, optimized for swept-source ophthalmic OCT, is described. The laser enables an effective 16 kHz sweep rate with >10 mm coherence length and a tuning range of approximately 35 nm full width at half...

Recent observations of excitonic coherences within photosynthetic complexes suggest that quantum coherences could enhance biological light harvesting efficiencies. Here, we employ optical pump-probe spectroscopy with few-femtosecond pulses to observe an excitonic quantum coherence in CdSe nanocrystals, a prototypical artificial light harvesting system. This coherence, which encodes the high-spe...

We describe an optical parametric oscillator that is pumped by population-trapped atoms that are prepared with maximum coherence. The oscillator is based on the use of an effective nonlinear susceptibility that is of the same order as the linear susceptibility. Because the parametric gain is obtained in a single coherence length, the gain bandwidth can exceed the degenerate frequency. In Pb vap...

academic) This thesis experimentally studies quantum interference phenomena and quantum coherence in mesoscopic systems, and quantum transport as well as magnetotransport in various materials system. One overarching aim is exploring the different mechanisms that give rise to quantum phase decoherence in lithographically patterned mesoscopic structures, of importance in the field of quantum tech...

The effective exciton coherence length in molecular aggregates is calculated using a nonlocal, real-space representation of the linear optical response. Simulations of polarized absorption and linear dichroism demonstrate that the spectra depend on local properties of the molecular aggregate segment where the exciton coherence is delocalized. This allows us to limit the calculations to small se...

Far field X-ray grating interferometry achieves extraordinary phase sensitivity in imaging weakly absorbing samples, provided that the grating period is within the transverse coherence length of the X-ray source. Here we describe a cost-efficient process to fabricate large area, 100 nm half-pitch hard X-ray phase gratings with an aspect ratio of 32. The nanometric gratings are suitable for ordi...

Some consequences of using partially coherent fields in the recently proposed method of power-extinction diffraction tomography are analyzed. It is found that the method is very tolerant of short spectral coherence lengths. The spectral coherence length of the field is shown to set the scale of a low-pass filter that acts on the subject. The implications of these results for implementation of t...

FRG The subgap conductivity of a normal-superconductor (NS) tunnel junction is thought to be due to tunneling of two electrons. There is a strong interference between these two electrons, originating from the spatial phase coherence in the normal metal at a mesoscopic length scale and the intrinsic coherence of the superconductor. We evaluated the interference effect on the transport through an...