A system for pulsed pumping was developed based on seven laser diodes with operation wavelength of 976 nm and decelerated optical power in CW of 10 W per diode. With appropriate electronic driver it is possible to achieve 150 W of pump peak power from whole pumping system. The integration of optical outputs was made with optical combiner in to the single passive optical fiber. Because of specific operation of pulsed driven laser diodes a temperature control was developed which allows us to change pumping wavelength to achieve optimal pumping conditions. The system has quick rise times of the pumping pulse in order of 10 ns.
F.01 Acquisition of new practical knowledge, information and skills
A thermal management system of a semiconductor laser diode has been developed. Thermal control of the diode’s case temperature provides the means to stabilize the wavelength of the emitted light during varying operating regimes. The system consists of a Peltier heat pump, an NTC temperature sensor and an industrial PID controller. A Matlab-based numerical model has been developed in order to simulate the system’s thermal response. Simulation-based measures have been introduced in order to reduce the transient response duration between the operating regimes as well as to reduce the energy consumption during the individual operating regime.
F.02 Acquisition of new scientific knowledge
A numerical model was developed for simulation of gain and Q-switched lasers using rate equations. They can describe spatially and time dependent changes of excited ions and photons in the laser cavity. Because changes are described in differential form and equations coupled trough mixed term, they must be integrated to yield desired results. For pulsed lasers these are: laser pulse width, amplitude and time of occurrence after we switch on the pump (for gain switched) or open the modulator (Q-switched). For describing these laser dynamics we developed model using adaptive numerical time integration of needed variables in discretized fiber laser. This numerical model was the core around which the software for modeling pulsed laser operation was written. With it a gain or Q-switched operation can be modeled. It allows for arbitrary pump profile shapes, operation regimes and transitivity functions of modulator in the case of Q-switched laser. Both types of simulations are not excluding and can be used together if application so requires. The user interface offers intuitive setup of laser operation and active fiber parameters. It provides results in graphic and numeric form, where both time and spatial dependencies can be seen.
F.05 Ability to launch new technological development cycle