A 900ps fiber amplifier was developed for the needs of the research. A microstructured fiber was used as the main amplifier fibre. A microstructured fiber can have a larger diameter core, which enables higher peak powers of such amplifiers. Power levels in excess of 100 kW were achieved using this setup. A additional AOM was used for pulse picking at the output of an amplifier.
F.04 Increase of the technological level
Development of Er: ZBLAN fiber laser operating in quasi-continuous mode based on fast switching of diode pumping. Peak power reached in the experiment at that time represented absolute record for this type of fiber lasers. Er: ZBLAN fiber lasers are particularly important, because their output wavelength is in the range 3μm, where water has a strong absorption peak. Such lasers are extremely important especially for medical applications, where absorption in biological samples (tissues) is desired. Today the area is still covered, so to speak exclusively with classic solid state lasers, such as the Er:YAG as active material and, consequently, free standing optics. Easy integration of optical fiber is not possible in this case. Standard optical fibers which are made of quartz (SiO2) light strongly attenuate light in this region and are therefore not suitable. Most promising at present are optical fibers based on ZBLAN, which can also be doped with active erbium ions. Unfortunately, it turns out that in this case the fiber is thermally and mechanically very sensitive. It was necessary to employ special technological processes both for the treatment of active optical fibers as well as for optical pumping. Part of this research, which is relevant to science was published "Optics Letters": entitled "High-power pulsed diode-pumped Er: ZBLAN laser".
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 2330980A pump laser system for fiber-based optical amplifiers has been developed. A temperature- and current-controlled, fiber-coupled, semiconductor laser diode has been used as the pump source. The diode’s fiber-guided output has been collimated using a precision positioning stage and a collimator lens. An optical isolator has been implemented as well in order to protect the diode from backward propagating light. The system is being used as a compact, narrowband, pump source for optical fiber amplifier test bench setups with a high electric-to-optical efficiency.
F.01 Acquisition of new practical knowledge, information and skills
A laser-diode-seeded continuous wave fiber laser, based on a master-oscillator-power-amplifier design has been developed. A single-stage ytterbium doped photonic crystal fiber amplifier has been used to amplify a polarized, single-transverse-mode, narrow-linewidth seed. The laser is capable of generating up to 7.5 W of output suitable for second harmonic generation that produces light in the green part of the visible spectrum. Such a light can be employed in various industrial applications such as thin-film micro-processing, as well as in medical applications.
F.01 Acquisition of new practical knowledge, information and skills
COBISS.SI-ID: 12069403The research was focused on development of a Q-switched fiber laser. Single-crystal photoelastic modulator (SCPEM) based on a LiTaO3 crystal was used as a Q-switch, which lead to a very simple and efficient Q-switching as the applied voltage to the crystal at resonant frequency was only 4.4V. Average power of the laser only decreased by about 1% after the SCPEM was introduced into the laser resonator. Laser pulses with duration of 120ns, energy levels around 26μJ and high slope efficiency (up to 60%) were achieved using this setup.
F.01 Acquisition of new practical knowledge, information and skills