The development of novel Al-, Ge- doped and un-doped standard single mode fibers for future optical communication at 2μm requires the integration of, among other pieces of equipment, an optical time domain reflectometry (OTDR) technique for precise spectral attenuation characterization, including the well-known cut-back method. The integration of a state of the art OTDR at 2μm could provide valuable attenuation information from the aforementioned novel fibers. The proposed setup consists of a 1.7 mW, 1960nm pump source, a 30 dB gain Thulium doped fibre amplifier at 2μm, an 0.8mm focal length lens with a 0.5 NA, a 30 MHz acusto-optic modulator, a 3.1 focal length lens with a 0.68NA, an optical circulator at 2μm, an InGaAs photodetector for 1.2 nm-2.6 nm range, a voltage amplifier and an oscilloscope. The propagated pulse rate is 50 KHz, with 500 ns, 200 ns, 100 ns and 50 ns pulse widths. Attenuation versus novel fibers types for lengths ranging from 400- to 1000- meter samples were obtained using the proposed setup.
The evolution of Stokes generation up to the n’th stage and the analytical solutions of commonly used Raman equations including numerical simulation and experimental results is reported. For the experimental work, a 1-km un-doped single-mode fiber was pumped with an ytterbium-doped fiber laser system (FL) in CW regime at 1064 nm in a free running configuration. We showed that it is possible to obtain up to the N’th power thresholds and maximum power for each Stokes by using compact analytical solutions as a first approximation in an arguably simple, quick process.
There are basically five nonlinear phenomena that occur in the optical fiber which limits the power or distort the signal in the data transmission. One of the most important is the phenomenon called Stimulated Brillouin Scattering (SBS) as it only requires relatively low pump power for affecting signal power in single and multiwavelength transmission in DWDM systems, for instance. There are numerous studies of this phenomenon that deal with power threshold determination which represents the limit on the transmit power but many of them are very complex and not very clear. In this work we propose a simple algorithm for the analysis and simulation of Brillouin power threshold by choosing a set-point. The results are obtained via solving the proposed set of coupled differential equations which then are compared to experimental results for Brillouin and Rayleigh scattering and forward power, i.e. residual pump.
In this work, the evolution of the nth analytical solutions of traditional Raman equations including numerical
simulation and experimental results is done. In the experiment an 8.6 Km single mode fiber was pumped with an
ytterbium doped fiber laser system (FL) in CW regime at 1064-nm in a free running configuration. We showed that
it is possible to obtain up to the nth power thresholds and maximum power for each Stokes by using compact
analytical solutions such as first approximations in an arguably simple, quick process.