A simple solution for producing nanosecond laser pulses can be obtained using gain-switched fiber lasers. In this paper, we present an optimized single stage gain-switched ytterbium-doped fiber laser. Three fiber lengths were tested to show the impact of length on the laser output pulse. A pulse as short as 28 ns at 1.4 kW peak power and a maximum peakpower of nearly 2 kW at 41 ns pulse duration was achieved. The laser possess a linear polarized output, very good beam quality of M2 ( 1.1, and a spectral bandwidth of 0.11 nm.
COBISS.SI-ID: 13354779
The operation of a gain-switched ytterbium-doped rod-type fiber laser is presented in this paper. The pumping, output pulses, spectrum, and energy stability are analyzed. The two key parameters of the laser pulse achieved from the single-stage gain-switched system are a 43 ns pulse duration and a peak power of 4.4 kW. This is to our knowledge the highest peak power obtained from single stage gain switched Yb-doped fiber laser. Further a very good pulse-to-pulse stability with standard deviation of less than 1% was achieved.
COBISS.SI-ID: 13806107
We investigate the influence of repetition rate on the operation and output of a gain-switched fiber laser. We derive an equation relating pump pulse duration to repetition rate, which provides insight into the parameters of the operating laser such as absorbed pump power and internal losses. The change in laser pulse duration with varying repetition rate is measured and found to be negligible. Finally, the derived theory is compared to experimental results obtained using a ytterbium-doped rod type fiber laser.
COBISS.SI-ID: 13637659
The gain-switched fiber laser presents the simplest construction among pulsed lasers in the nanosecond region and consequently is also very robust. These properties make it potentially appropriate for industrial applications, especially in some types of microprocessing. However, careful design of such lasers is important in order to reach the required pulse parameters (peak power and pulse duration). To design and optimize a gain-switched fiber laser for microprocessing, a numerical model using time and spatial dependencies was developed and reported in this paper. The effects of pump power and laser length on the pulse duration and peak power were investigated by modeling gain-switched operation. Further, the results of modeling were compared to data from an experimental setup based on a Yb3-doped gain-switched fiber laser, revealing good agreement.
COBISS.SI-ID: 12826395
We present an experimental and numerical analysis, how deviations of the multiplexer-retardation influence the output power of a time-multiplexed dual channel laser. The laser has two different channels, each one with its own gain medium. The channels are timemultiplexed by a single crystal photo-elastic modulator. It enables to double the repetition rate and output power of the laser. However, as multiplexing is based on polarization- switching, the retardation of the modulator should be kept within certain limits. By experimental measurement and theoretical analysis, we determine the operational window within which the retardation should be kept to avoid additional losses into the resonator. The analysis was done for two configurations of the laser setup, namely with and without a quarter-wave plate.
COBISS.SI-ID: 12825115