Abstract
In this work we present a possible "way-to-go" for all-optical processing, shortening the distance between typical all-optical scenarios and real standardized optical networks. This is based on the usage of dualpolarization quadrature phase-shift keying (DP-DQPSK) for transmission with subsequent conversion to amplitude shift-keying for optical processing in metro/access network scenarios. In the last years, a strong push towards 100 Gbit/s technology developments has been done by major operators. The achieved developments indicate that future for high bit rate transmission in long-haul networks is reserved for phase modulation formats (like DP-QPSK) with coherent detection and subsequent electronic processing to mitigate transmission impairments. As this is becoming obvious for long-haul networks where high performance in transmission is required, the same is not applied to metropolitan networks. First of all the push for 100Gbit/s in metro hasn't been as strong as in long-haul (but it will come soon) and second, metro networks are much more cost sensitive and need less transmission performance, therefore the price of coherent detection and electronic processing might be difficult to realize when 100 Gbit/s come to the metro region. It can, therefore, be expected that amplitude modulation (AM) formats will still domain the metro area. Typical all-optical processing use AM signals which means that for metro networks there may still be a role for it. Recently, a transparent node connecting regio/metro to metro/access network rings was successfully demonstrated [1], [2]. There, full mux/demux between optical time domain multiplexed (OTDM) signals in regio/metro ring and wavelength division multiplexed (WDM) signals in metro/access was shown using AM signals. This experiment showed the potential of all-optical processing in terms of performance, cost and power savings. All-optical conversion between phase modulated (PM) and AM signals was demonstrated both with semiconductor optical amplifiers (SOAs) [3] and highly nonlinear fibres (HNLF) [4]. This means that, in principle, it is possible to merge the best of the two worlds; tight spectral occupation from long-haul DP- (D)QPSK and all-optical processing from AM signals in metro region. This might be the "way-to-go" for all optical processing. © 2009 IEEE.

Abstract
Phase-shifted Bragg Grating Waveguide filters were formed in bulk glass for the first time by femtosecond laser direct writing. A narrow, tunable 0.1-nm transmission window at 1550-nm is demonstrated for tunable p and other phase-shifts. © 2009 Optical Society of America.

Abstract
Fiber Bragg gratings (FBGs) are today fundamental components in fiber optics. They can be used as sensors, in signal processing, e.g. telecom applications, as wavelength stabilizers in fiber lasers or in dispersion compensators. However, there are applications where the demand for fiber Bragg gratings is not compatible with standard photosensitivity techniques like germanium doping or hydrogen loading. Examples are their use as laser-mirrors in spliceless all fiber fiber-laser solutions or the fiber Bragg grating inscription in suspended core all silica fibers for evanescent field sensing. Fiber Bragg grating inscription with femtosecond-laser exposure is a challenging new method to realize grating structures for waveguides made of materials which do not provide UV-photosensitivity. Especially fs-IR-inscription has been demonstrated for Bragg grating inscription in a variety of material systems such as boron-silica glass, sapphire and pure silica glass. The feasibility of the phase mask FBG inscription technique with DUV femtosecond lasers was also shown, which allows grating inscription even in pure silica microstructured fibers. The phase mask inscription method requires that the fiber will be placed directly behind the phase mask. While the laser beam should be focused onto the fiber to support nonlinear material interaction, this inscription method also leads to phase mask degradations, presumably due to non-bridging oxygen holes (NBOH). Our solution to avoid the mask degradation is to increase the space between fiber and phase mask by using a Talbot-interferometer. Another advantage is the wavelength versatility of this inscription setup. Due to the short temporal coherence length of the femtosecond pulses, the angular alignment variability of the interferometer mirrors is limited and restrictions concerning the wavelength versatility of the interferometer arise. Grating arrays in pure silica suspended core fibers are demonstrated as an example for the versatility of the inscription arrangement. © 2009 SPIE.

Abstract
Chick embryos are among the most studied species in development biology because they are easily obtained, highly accessible and present a similar development to that of humans. Normally morphological studies are carried out with confocal microscopy, however in-situ imaging is impossible and in-vivo imaging can only be performed with great difficulty. For confocal microscopy the embryo has to be studied outside the egg, what generally also means a short life expectancy of the embryo. Additionally, extracting the embryo of the egg precludes the possibility of studying its development in its natural environment. In this paper it is shown that en-face optical coherence tomography (en-face OCT) is a possible solution to overcome these difficulties allowing for an in-situ and in-vivo study over a timescale of several days. With en-face OCT it is possible to accompany the development of one single embryo over several days and to acquire high resolution and axially resolved images. © 2009 SPIE-OSA.

Abstract
We discuss and compare several concepts of optical cryptographic systems currently being proposed to improve communication security, their strong points and weaknesses. We will focus on approaches based on chaos synchronization.

Abstract
It has been suggested that dark matter particles which scatter inelastically from detector target nuclei could explain the apparent incompatibility of the DAMA modulation signal (interpreted as evidence for particle dark matter) with the null results from CDMS-II and XENON10. Among the predictions of inelastically interacting dark matter are a suppression of low-energy events, and a population of nuclear recoil events at higher nuclear recoil equivalent energies. This is in stark contrast to the well-known expectation of a falling exponential spectrum for the case of elastic interactions. We present a new analysis of XENON10 dark matter search data extending to E(nr)=75 keV nuclear recoil equivalent energy. Our results exclude a significant region of previously allowed parameter space in the model of inelastically interacting dark matter. In particular, it is found that dark matter particle masses m(chi)greater than or similar to 150 GeV are disfavored.