[en] 13 papers from the field of holography are dealt with. (WL/AK)

[en] We report on an ytterbium-doped fiber laser (FL) remotely pumped by a commercial Yb:YAG thin-disk laser with a beam parameter product of 4 mm mrad and an emission wavelength of 1030 nm. The pump light absorption is 1.4 dB/m, which is 77 times lower than the peak value at 976 nm. The high-brilliance pumped fiber laser with a double pass of the pump light yielded a maximum output power of 1008 W out of 1264 W pump power. Despite the low pump absorption at 1030 nm, this kW-fiber laser reaches an excellent optical-to-optical efficiency of 80%. This concept of high-brilliance pumping enables to overcome the nonlinear effects limiting high-power high-brightness beam delivery over long distances and offers a power scalability fiber lasers paired with flexibility in the application

[en] We report on a tapered large-core Yb fiber laser operating at 976 nm emission wavelength. It was realized using a high-numerical aperture large-core fiber with 126 μm core diameter, which was fabricated by powder-sinter technology and shows a very homogeneous step-index profile. The end of the fiber is tapered down to match a single-mode fiber containing a fiber Bragg grating. Using the benefits of core-pumping and the feedback of the spliced fiber Bragg grating, we achieved efficient pump light absorption and wavelength stable 976 nm lasing with single-mode performance. We could demonstrate 10 W laser power out of a 10 μm fiber core with a slope efficiency of 31% with respect to the launched pump power. The presented device is well-suited for fiber-coupled pumping of amplifiers for high peak power. (letter)

[en] A simplified setup for coherent anti-Stokes Raman scattering (CARS) microscopy is introduced, which allows for recording CARS images with 30 cm^-1 excitation bandwidth for probing Raman bands between 500 and 900 cm^-1 with minimal requirements for alignment. The experimental arrangement is based on electronic switching between CARS images recorded at different Raman resonances by combining a photonic crystal fiber (PCF) as broadband light source and an acousto-optical programmable dispersive filter (AOPDF) as tunable wavelength filter. Such spatial light modulator enables selection of a narrow-band spectrum to yield high vibrational contrast and hence chemical contrast in the resultant CARS images. Furthermore, an experimental approach to reconstruct spectral information from CARS image contrast is introduced

[en] In this letter we present an approach to CARS microscopy, which compromises between fast acquisition rates and the amount of chemical information obtained. By using a light modulator as tunable filter in concert with narrowband pump and broadband Stokes pulses, we demonstrate an experimental arrangement, which allows for fast electronic switching between CARS images recorded at different Raman resonances without the need for any optical adjustment

[en] In many laser spectroscopic techniques, such as fluorescence Raman and resonance Raman spectroscopy the choice of laser excitation wavelength is of central importance. Thus, it is desirable to have a single laser light source where the wavelength can be tuned fast, easily and continuously without the necessity of changing the optical alignment. Here, such a light source is presented combining a broad spectrum with a spatial light modulator as tunable filter. The feasibility of this setup for Raman spectroscopy is demonstrated

[en] A vibration sensor based on a distributed Bragg reflector (DBR) is proposed. The gratings that form the cavity are written in erbium-doped fibre using the femtosecond laser technique. In this configuration, one grating of the DBR acts as a sensor whilst the other one acts as a spectral filter. The active sensor, subjected to vibration measurements, exhibits a response of up to ∼1.5 kHz. (letter)