The behavior of stimulated Brillouin scattering (SBS) and Rayleigh backscattering phenomena, which limit the forward transmission power in modern, ultra-long haul optical communication systems such as dense wavelength division multiplexing systems is analyzed via simulation and experimental investigation of threshold and maximum power. Evolution of SBS, Rayleigh scattering and forward powers are experimentally investigated with a 25 km segment of single mode fiber. Also, a simple algorithm to predict the generation of SBS is proposed where two criteria of power thresholds was used for comparison with experimental data.

There are many applications where it is necessary to model queuing systems that involve finite queue size. Most of the models consider traffic with Poisson arrivals and exponentially distributed service times. Unfortunately, when the traffic behavior does not consider Poisson arrivals and exponentially distributed service times, closed‐form solutions are not always available or have high mathematical complexity. Based on Lindley’s recursion, this paper presents a fast simulation model for an accurate estimation of the performance metrics of G/G/1/K queues. One of the main characteristics of this approach is the support for long‐range dependence traffic models. The model can be used to model queuing systems in the same way that a discrete event simulator would do it. This model has a speedup of at least two orders of magnitude concerning implementations in conventional discrete event simulators.

This work presents an algorithm to reduce the multiplicative computational complexity in the creation of digital holograms, where an object is considered as a set of point sources using mathematical symmetry properties of both the core in the Fresnel integral and the image. The image is modeled using group theory. This algorithm has multiplicative complexity equal to zero and an additive complexity (k − 1)N² for the case of sparse matrices or binary images, where k is the number of pixels other than zero and N² is the total of points in the image.

<!-- *** Custom HTML *** --> The temperature response of a tapered holmium-doped fiber amplifier and its impact in the performance of fiber lasers and temperature fiber sensors has numerically been analyzed. Different pump schemes and different longitudinal shapes of the tapered-doped fiber were investigated, and it was found that a parabolic shape of the tapered fiber amplifier in a co-propagating pump scheme shows the highest sensitivity to temperature changes. In particular, the temperature sensitivity of the amplified signal was 2.5 × 10^−  4 ° C for 1 W of pump power and 1 m of doped fiber length. In addition, this sensitivity can be increased up to 10 times for fiber lengths shorter than 1 m and pump powers lower than 300 mW. Our results can be used to describe the temperature response of tapered fiber amplifiers in the mid-infrared spectral region and contribute with new information for the development of fiber lasers and fiber temperature sensors.