| Abstract [eng] |
Laser source versatility is an important aspect of a laser system, which provides an opportunity to use the laser system for multiple applications. The systems versatility is defined by its ability to control the fundamental laser pulse parameters. Laser pulse duration is one of the most important laser source parameters, which determines the possible applications of the laser system. A big advantage of a laser source is the ability to control the pulse duration in a large range. An active fiber loop with integrated spectral filtering enables pulse duration control from tens to hundreds of picoseconds. One of the main advantages of this technology is that the formed pulses retain a Gaussian like temporal form in the whole pulse duration tunning range. GHz bursts is a perspective method for material processing, the method provides enhanced efficiency, processing speed and processing quality. Common problems while forming GHz burst are the lack of control of the pulse amplitude within the burst, which is usually decaying. Also, most methods do not permit any control of the length of a formed GHz bursts and cannot be used to change the form of the bursts and are not well suited for ultra-short pulses. On the other hand, GHz burst forming with an active fiber loop provides a unique opportunity to control pulse amplitude within the burst, actively control the length and form of the GHz burst and is well suited for ultra-short pulses, because it incorporated dispersion compensation within the loop. GHz burst forming with an active fiber loop has a lot of flexibility and can be fine-tuned for specific applications. Additionally, when using an acousto-optic modulator that has a transmission function which is controlled by an arbitrary wave generator it is possible to form bursts of varies forms. It allows forming of rectangular shaped pulse packets as well as a rising pulse amplitude bursts that are particularly useful when amplifying GHz bursts, because of the inequal amplification of pulses within the burst. Single pulse amplitude control within the burst, if possible, when using a sufficiently fast arbitrary wave generator. Therefor active fiber loop technology is a perspective and universal method that allows the control of a laser pulse duration in a large range while preserving a Gaussian like temporal form. Additionally, this technology provides a versatile approach to forming GHz bursts. GHz burst forming with an active fiber loop allows customizing of the formed burst according to a specific application. |
