A distributed sensing system for apolar hydrocarbons is presented which is built from a chemically sensitive polymer-clad silica fiber adapted to an optical time domain reflectometer (OTDR) setup. OTDR measurements allow locating and detecting chemicals by measuring the time delay between short light pulses entering the fiber and discrete changes in the backscatter signals that are caused by lo...

This study examined the proposition that competing against red-clad opponents hinders the performance of soccer (football) athletes. 40 experienced players took 10 penalty kicks against a goalkeeper wearing a black jersey and, 1 week later, took 10 penalty kicks against a goalkeeper wearing either a red, green, blue, or yellow jersey. Prior to each set of kicks, participants reported their expe...

We analyze the influence of heat generation caused by nonradiative transitions in a high-power 1.55 microm double-clad erbium-ytterbium fiber laser on the Stark level population. At strong pumping rates, 1 microm lasing can start as a result of parasitic reflections. We present a model that allows us to simulate the effect of self-generated heat on the Stark level population by using the MacCum...

We present multiphoton microendoscopy with a rotational probe and a 1 m fiber-based femtosecond laser. The rotational probe is based on a double-clad photonic crystal fiber, a gradient index lens, a microprism, and a rotational microelectronicmechanical system (MEMS) motor. The MEMS motor has a diameter of 2.2 mm and can provide 360° full-view rotation. The fiber laser provides ultrashort pulse...

A Fiber Bragg grating of 369 nm pitch was inscribed in a germanium-free double-clad ytterbium doped silica fiber using a femto-second pulse train at 400 nm wavelength and a phase mask. The photo-induced refractive index modulation of higher than 4 x 10(-3) was obtained and the accompanying photo-induced losses were subsequently removed by thermal annealing, resulting in a low loss (<0.1 dB), st...

A study of using a single crystal photo-elastic modulator for active Q-switching of a fiber laser is presented. The modulator, which oscillates in a longitudinal eigenmode, was realized with LiTaO(3). This induces due to the photo-elastic effect a modulated artificial birefringence which modulates the polarization of passing light. When used together with a polarizer inside a laser cavity the l...

We demonstrate a refractive index sensor based on a long period grating (LPG) inscribed in a special photosensitive microfiber with double-clad profile. The fiber is tapered gradually enough to ensure the adiabaticity of the fiber taper. In other words, the resulting insertion loss is sufficiently small. The boron and germanium co-doped inner cladding makes it suitable for inscribing gratings i...