Temperature and pump modulation investigation of an Er:Yb co-doped fiber laser with optimized SWaP

This paper presents the results of experimental and theoretical studies of the influence of temperature and pump modulation on an erbium:ytterbium co-doped fiber laser in context for an optimized size, weight, and power (SWaP) integration. The fiber laser setup including the active fiber and pump diode lasers are heated up or cooled down for ranging temperatures from 0°C till 60°C and in parallel the output power is measured. Experimental results show that the slope efficiency of the fiber laser is constant over the measured temperature range. A slight decrease of the electro-optical conversion efficiency with increasing temperature is observed. Furthermore, the erbium:ytterbium co-doped fiber laser is pump modulated and the rise time as well as the frequency response is measured. The experimental results of the pump modulated fiber laser are compared with a time resolved simulation. The investigation shows that a minimum rise time of 36.6 µs and a maximum modulation depth of 9.4 dB can be reached. Moreover, the modulated laser amplitude is measured. The laser amplitude experiences a 3 dB attenuation at a modulation frequency of 20 kHz that agrees with the simulation results taking partly coupled ytterbium ions into account.