We show by numerical modeling that saturation of the population inversion reduces the stimulated thermal Rayleigh gain relative to the laser gain in large mode area fiber amplifiers. We show how to exploit this effect to raise mode instability thresholds by a substantial factor. We also demonstrate that when suppression of stimulated Brillouin scattering and the population saturation effect are...

Coherent beam combining enables power scaling beyond the limits of single amplifiers. Therefore, improving the performance and simplicity of coherent combination techniques is of great interest for many high power applications. Here, we show all-fiber coherent beam combining of two ytterbium doped amplifiers with and without a dedicated phase actuator and a total output power up to 25 W. Instea...

Conventional pipelined ADCs use electronic feedback to achieve highly linear and drift insensitive transfer characteristics in their interstage gain elements. Especially in the converter frontend, amplifiers with large open-loop gain are needed to achieve the desired accuracy. Due to additional, conflicting low noise and high bandwidth requirements, precision amplifiers dominate the power dissi...

We theoretically and numerically study the difference frequency generation and the signal amplification bandwidth together with the pump wavelength acceptance for counterpropagating optical parametric amplifiers. It is shown that the specific advantage of those amplifiers is that the DFG and amplification bandwidth is much narrower than in a co-propagating scheme, thus making it possible to shi...

We use a detailed numerical model of stimulated thermal Rayleigh scattering to compute mode instability thresholds in Tm(3+)-doped fiber amplifiers. The fiber amplifies 2040 nm light using a 790 nm pump. The cross-relaxation process is strong, permitting power efficiencies of 60%. The predicted instability thresholds are compared with those in similar Yb(3+)-doped fiber amplifiers with 976 nm p...

In this contribution, a set of robust GaN MMIC T/R switches and low-noise amplifiers, all based on the same GaN process, is presented. The target operating bandwidths are the X-band and the 2-18 GHz bandwidth. Several robustness tests on the fabricated MMICs demonstrate state-ofthe-art survivability to CW input power levels. The development of high-power amplifiers, robust low-noise amplifiers ...

For low-voltage, low-power circuit design, the linear model for operational amplifiers is insufficient to accurately predict the static and dynamic behavior of the circuit. This paper introduces a nonlinear model for operational amplifiers based on amplifiers’ DC transfer characteristic. By using this nonlinear model, the behavior of an operational amplifier with feedback network can be describ...