We report, for the first time to our knowledge, the presence of concentration-induced nonuniform power in tunable erbium-doped fiber lasers. A theoretical model is proposed with pair-induced quenching taken into account. We obtain good agreement between numerical and experimental results of a high-concentration erbium-doped fiber ring laser with a large tuning range of over 100 nm. These findin...

performance of the fiber optic networks with different physical topologies such as point-to-point, bus, ring and star, with respect to requirements as bit rates, topology structure, bit. error rate (ber) and optical component characteristics including optical amplifiers, filters, sources and detectors, are analyzed and simulated. for this purpose, maximum number of supportable nodes and throug...

A compact tunable 10 W picosecond source based on Yb-doped fiber amplification of gain switch laser diode has been demonstrated. A gain switch semiconductor laser diode was used as the seed source, and a multi-stage single mode Yb-doped fiber preamplifier was combined with two large mode area double-clad Yb-doped fiber main amplifiers to construct the amplification system. The tunable pulses wi...

We report the fabrication and characterization of a photonic crystal fiber (PCF) having a sol-gel core doped with ionic copper. Optical measurements demonstrate that the ionic copper is preserved in the silica glass all along the preparation steps up to fiber drawing. The photoluminescence results clearly show that such an ionic copper-doped fiber constitutes a potential candidate for UV-C (200...

To accommodate rapidly increasing quantities of information and communication, optical fiber transmission technology with high-speed high-capacity is demanded. The development of an optical gain medium and fiber amplifiers to cover the 1250~1650 nm region, which is the entire optical telecommunication windows of silica fiber, becomes an important issue for ultra-wide broadband optical communica...

A nonlinear coefficient of 3.6-4.1  W-1  km-1 and group velocity dispersion of -20  ps2/km of a commercial core-pumped thulium-doped fiber have been evaluated using degenerate four-wave mixing at 2 μm. The anomalous dispersion behavior of the fiber has been confirmed by linear measurements with an all-fiber Mach-Zehnder interferometer (MZI). Additionally, no pum...

A radiation resistant optical fiber used in a broadband source is presented. Both ASE source and Fiber Optical Gyroscope (FOG) commonly used in space missions, suffer from failures and degradation after long term exposure to radiative environment. The aim of this article is to present the results of our investigation on fiber and ASE source architecture in order to design a Radiation Resistant ...

A compact all-fiber Faraday isolator and a Faraday mirror are demonstrated. At the core of each of these components is an all-fiber Faraday rotator made of a 4-cm-long, 65-wt%-terbium-doped silicate fiber. The effective Verdet constant of the terbium-doped fiber is measured to be -32 rad/(Tm), which is 27 x larger than that of silica fiber. This effective Verdet constant is the largest value me...

A compact upconversion fiber laser operating around 810 nm is proposed using thulium-doped silica-based fiber with locally modified thulium environment by high alumina codoping. Using a comprehensive numerical model of thulium doped fiber we investigate performance of the proposed laser. Comparison with two other thulium hosts, fluoride glass and standard silica, is presented. Efficient lasing ...

The transition rate of the stimulated emission at the higher energy levels of the excited states in a silica-based erbium-doped fiber can be enhanced by introducing fundamental-mode cutoff filtering mechanism. The electrons excited by optical pumping can more occupy the higher energy levels of the excited states when the transition rate for the lower energy levels (longer wavelengths) of the ex...