Co-doped Glass Waveguide Research Articles

Optimization of Concentration Quenching on Erbium Ytterbium Doped Wave Guide EYDWA Using for Extended Reach up to 160 Km of Hybrid Gigabit Passive Optical Networks and Free Space Optical Technologie “GPON-FSO”

Abstract The purpose of this paper is to demonstrate an implementation of Er3+/Yb3+ codoped glass waveguide amplifiers (EYDWA) as a post-amplifier can provide an extended reach and a high split-ratio for the cost-effective implementation of hybrid fiber-to-the-x (FTTx) and free space optical (FSO) technologies. The performance has been compared on the basis of transmission distance, however the results of simulation show enhancement offered by EYDWA. This amplifier was able to reach transmission distance ratio of 160:5 km for GPON:FSO. Moreover in this paper, was study different characterizations of EYDWA amplifier, which depend essentially on the opt-geometric parameters, such as concentrations of ions erbium, length of the waveguide amplifier and the effect of those parameters to optimize the gain G, quality factor Q, min of BER and eye diagram.

Research on the influence of fabrication parameters on the performance of buried ion-exchanged glass waveguides using the variational method

The variational method is proposed to analyze the influence of the fabrication parameters on the performance of buried K+-Na+ ion-exchanged Er3+-Yb3+ ions co-doped glass waveguide. The unknown parameters of the Hermite-Gaussian functions as the trial field distribution are determined based on the scalar variational principle. It is demonstrated that the results calculated in this paper agree with those measured in the experiment. The mode dimensions, the effective refractive index, and the overlap factor as the functions of the fabrication parameters are investigated. These results of the variational analysis are useful for the design and optimization of Er3+-Yb3+ ions co-doped waveguides.

Modeling and experiments of packaged Er 3+–Yb 3+ co-doped glass waveguide amplifiers

A full characterization of packaged Er 3+–Yb 3+ co-doped waveguide amplifiers (EYDWAs) fabricated using ion-exchange and field-assisted annealing was reported. The amplifier was modeled using an extended overlapping factors method, and two overlapping factors at the pump and signal wavelengths were introduced to simplify the overlapping integrals between levels’ population densities and mode intensity profiles. The rate equations and the propagation equations depend on one variable: the longitudinal parameter z, and the overlapping integrals have to be carried out once only. The gain and noise characteristics of the EYDWAs were investigated, and there is good agreement between the theoretical and experimental results. With a single 975 nm diode pump of 200 mW power, this packaged ∼4.0 cm long waveguide device delivers a total net gain of ∼12.0 dB peak value at 1.534 μm, and a net gain of ∼8.0 dB and an average noise figure of ∼5.1 dB in the 1530–1560 nm band. The polarization dependent gain of <0.2 dB is also estimated for the device. Comparing to commercially available Er-doped fiber amplifiers, these low cost, high gain pigtailed glass waveguide amplifiers have a great potential to be used in optical access networks.

Er3+–Yb3+ co-doped glass waveguide amplifiers using ion exchange and field-assisted annealing

Er3+–Yb3+ co-doped waveguide amplifiers fabricated using thermal two-step ion-exchange are demonstrated. K+–Na+ ion-exchange process was first carried out in pure KNO3 molten bath, and then field-assisted annealing (FAA) was used to make the buried waveguides. The effective buried depth is estimated to be ∼3.4μm for the buried FAA waveguides. With the use of cut-back method, the fiber-to-guide coupling loss of ∼4.38dB, the waveguide loss of ∼2.27dB/cm, and Er3+ absorption loss ∼5.7dB were measured for a ∼1.24-cm-long waveguide. Peak relative gain of ∼7.0dB is obtained for a ∼1.24-cm-long waveguide. The potential for the fabrication of compact optical amplifiers operating in the range of 1520–1580nm is also demonstrated.

Modelling of diffractive structures in photorefractive Er/Yb–co-doped glass waveguides

The photorefractive properties of Ge-doped glasses are routinely exploited for the production of Bragg gratings in optical fibres. Today, the most common fabrication procedure relies on the phase-mask technique, which allows to produce (through UV irradiation) a periodical refractive index variation in Ge-doped fibre cores. The same methodology can be applied to integrated optical components in photorefractive glass planar substrates. If rare earth ions (such as erbium and ytterbium) are included in the glass matrix, both active and photorefractive properties can be combined in the same material. This fact allows for the possibility of realizing complex integrated optical components, such as Bragg-reflection lasers and amplifiers. In this work, a numerical analysis of a waveguide Bragg reflector is presented based on a homemade modelling technique.

Duty cycle ratio dependence on the performance of a Q-switched laser with an Er^3+–Yb^3+ codoped glass waveguide

We examine the performance of a hybrid Q-switched LiNbO(3) and Er(3+)-Yb(3+) doped glass waveguide laser as a modulation function of the duty cycle ratio. As the duty cycle ratio decreases, the laser operates at higher peak power and pulse width. At low duty cycle ratio (<1%), we observe variations in the Q-switched pulse shape; while the laser produces 59-W and 200-ns pulses to a 1-kHz repetition rate for a 50% duty cycle, it yields 27-W and 100-ns pulses to a 10-kHz repetition rate for a 0.01% duty cycle.

High power Er +3 -Yb +3 co-dopedglass waveguide Q -switched laser

Using a Q-switched Er+3-Yb+3 co-doped glass waveguide laser, the authors have obtained 67 W peak power and 200 ns wide optical pulses with a pulse energy of 13.4 µJ for a 7 m long cavity at a 1 kHz repetition rate. The dependence of the pulsewidth on the cavity length has also been investigated, and indicated that integration of this laser in a 10 cm long cavity would provide 2 ns wide optical pulses with 7 kW peak power.

Hybrid Q-switched laser with Ti-indiffused LiNbO3and Er-Yb co-doped glass waveguides

We report the design and characterization of a novel Q-switched laser configuration based on a composite Er/sup +3/-Yb/sup +3/ co-doped ion-exchanged glass and Ti-indiffused LiNbO/sub 3/ waveguides. This 1536 nm Q-switched laser provides stable 200 ns wide optical pulses for a cavity length of 7 m with a peak power of 13.5 W and a pulse energy of 2.7 /spl mu/J at a 2-kHz repetition rate and 180 mW of 980-nm pump power. Also, we examine the dependence of the pulsewidth and peak power on the laser cavity length to estimate the performance of the integrated version of such a laser.

Improved gain characteristics in high-concentration Er/sup 3+//Yb/sup 3+/ codoped glass waveguide amplifiers

High-concentration Er/sup 3+//Yb/sup 3+/ codoped glass waveguide amplifiers are analyzed by means of a finite-element-based code. Efficient Yb/sup 3+/ to Er/sup 3+/ energy transfer is shown to be a useful mechanism to reduce performance degradation due to Er/sup 3+/ ion-ion interactions. Numerical calculations based on realistic waveguide parameters demonstrate the possibility of achieving high gain with a short device length. >