Codoped Phosphate Glass Waveguide Research Articles

Guided-Wave Up-Conversion Luminescence in Er3+/Yb3+ Co-doped Phosphate Glass Waveguide Produced by Direct Femtosecond Laser Writing

We report on guided-wave up-conversion luminescence in femtosecond laser writing cladding waveguides in Er3+/Yb3+ co-doped phosphate glass. The waveguides were fabricated with 30-μm- and 100-μm-diameter of the guiding cores. The guiding properties of waveguides have been investigated at 633 nm by end face coupling of free space light and physical contact of fibers. The experimental and calculated results of propagating modal profiles and losses have proved favorable performances suitable to Gaussian mode field and multi-mode applications. Under the optical pump laser at 980 nm, the guided-wave up-conversion luminescence at visible light range has been realized through the waveguides.

Er3+/Yb3+ co-doped phosphate glass waveguides formed by the H+ ion implantation

The 400 keV proton implantation with a fluence of [Formula: see text] ions/cm2 was applied on the [Formula: see text] co-doped phosphate glass to fabricate a planar waveguide structure. The mode profile at the end face of the waveguide was measured by the end-face coupling technique. The energy loss profile of the energetic protons was calculated by the SRIM 2013. The refractive index distribution was simulated by the reflectivity calculation method. Based on these results, the formation theory of the planar waveguides was discussed through simulating the energy loss distribution and analyzing the reconstructed refractive index profile, which could be used for applications in the future integrated optical systems.

Near-infrared carbon-implanted Er3+/Yb3+ co-doped phosphate glass waveguides

The Er3+/Yb3+ co-doped phosphate (EYDP) glass waveguides operated at 1539 nm have been manufactured by using the implantation technique of carbon ions under the condition of 6.0 MeV energy and 5.0 × 1013 ions/cm2 fluence in this work. The ion implantation process was computed by means of the stopping and range of ions in matter. The dark-mode spectrum at 1539 nm of the waveguide was recorded by the method of the prism coupling measurement. The microscopic image of the fabricated structure was photographed by an optical microscope. It is the first step for the application of the waveguides on the base of EYDP glasses in optical-integrated photonic devices at near-infrared band.

Concentration-dependent optimization of Yb3+/Er3+ highly-doped phosphate glass waveguide amplifiers and lasers using a microscopic statistical formalism

The dependence of the optimal performance of bidirectionally-pumped integrated amplifiers and lasers based on fs-laser written Yb3+/Er3+-codoped phosphate glass waveguides on the concentration of dopants is numerically analysed. A novel macroscopic rate-equation propagation model is used which considers concentration-dependent rates for the energy-transfer inter-atomic migration-assisted mechanisms. Optimal small-signal gain for an amplifier and output laser power for a ring laser are computed for various working conditions and broad dopants-concentration ranges. Optimal waveguide lengths are also analysed in detail. The large variations obtained in the dopants concentration required for optimal amplifier gain or output laser power and in the waveguide optimal length confirm that a previous rigorous numerical design is essential in order to achieve the optimized performance of these active devices.

EFFECT OF TRANSMISSION FUNCTION OF CASCADED MULTILAYER MEDIUM THIN FILM FILTER ON Er–Yb CO-DOPED WAVEGUIDE AMPLIFIERS

Modeling and amplification of erbium–ytterbium co-doped phosphate glass waveguide amplifier with a cascaded multilayer medium thin film filter is investigated theoretically. This proposed filter consists of some different filtering unit cells with different central wavelength and bandwidth, and each cell can suppress certain peak gain at a specific wavelength. The intrinsical gain spectrum of amplifier is obtained by solving a set of rate and power propagation equations, the effect of transmittance spectrum of thin film filter on flattening gain is discussed, and the transmission function of cascaded multilayer medium thin film filter is obtained.

Evaluation of Optical Path Designing on 4x4 Cm<sup>2</sup> Er<sup>3+</sup>/Yb<sup>3+</sup> Doped Phosphate Glass Waveguide Substrate

To achieve high-gain C-band waveguide amplifiers with integrated configuration, bent channel structures (S-, U-, and F-bend) based on buried Er3+/Yb3+ codoped phosphate glass waveguide channel fabricated by field-assisted annealing (FAA) have been designed in a 4´4 cm2 substrate. Using simulated-bend method, the optimal radius for the curved structure is derived to be 1.00 cm with loss coefficient of 0.0045 dB/cm. In the wavelength range of 1520-1575 nm, obvious gain enhancement for the bent structure waveguides is anticipated, and for the F-bend waveguide, the net gain at 1534 nm wavelength is derived to be 43.95 dB, which is much higher than the value of 26.67 and 13.20 dB in the U- and S-bend waveguides, respectively, and over three times higher than that of the straight one. The simulation results indicate that the bent structure designing is beneficial in obtaining high signal gain in buried Er3+/Yb3+ codoped phosphate glass waveguides, which lays the foundation for the further design and fabrication of integrated devices.

Bent channel design in buried Er<sup>3+</sup>/Yb<sup>3+</sup> codoped phosphate glass waveguide fabricated by field-assisted annealing

Bent waveguide structures (S-, U-, and F-bend) based on buried Er 3 + /Yb 3 + codoped phosphate glass waveguide channel fabricated by field-assisted annealing have been designed to achieve high-gain C-band integrated amplification. Using a simulated-bend method, the optimal radius for the curved structure is derived to be 0.90 cm with loss coefficient of 0.02 dB/cm, as the substrate size is schemed to be 4×3 cm 2 . In the wavelength range of 1520 to 1575 nm, obvious gain enhancement for the bent structure waveguides is anticipated, and for the F-bend waveguide, the internal gain at 1534-nm wavelength is derived to be 41.61 dB, which is much higher than the value of 26.22 and 13.81 dB in the U- and S-bend waveguides, respectively, and over three times higher than that of the straight one. The simulation results indicate that the bent structure design is beneficial in obtaining high signal gain in buried Er 3 + /Yb 3 + codoped phosphate glass waveguides, which lays the foundation for further design and fabrication of integrated devices.

Design and Simulation of Broadband IR integrated Waveguide Amplifiers with Long - Period Waveguide Grating Filter

A novel broadband IR integrated Er-Yb codoped phosphate glass waveguide amplifier with a long-period waveguide grating is proposed. The long-period waveguide grating, which is used as a gain equalizer, is directly fabricated in the waveguide. The amplifier model is based on propagation and population-rate equations and includes both uniform and pair-induced up-conversion mechanisms. It is solved numerically by combining overlapping integral and Runge-Kutta(RK) algorithm. The intrinsical gain spectrum of the proposed amplifier is obtained by solving a set of rate and power propagation equations and, the deleterious gain peaking is reduced by the long-period waveguide grating filter. The effects of transmission spectrum of the proposed long-period grating on flattening gain are discussed. An average gain ~ 20dB between 1532 nm and 1565 nm with gain difference of < 3dB is achieved.

S-Type Er-Yb Co-doped Phosphate Glass Waveguide Amplifier Integrated with Thin-film Filter

A new S-type of wideband erbium-ytterbium co-doped phosphate glass waveguide amplifier integrated with medium thin film filter is proposed, this S-type geometry waveguide structure is used to achieve a long path in a compact chip, and obtained higher gain with lower Er-doped concentration, and the medium thin film filter is utilized to achieve the built-in suppression of 1.53pm gain peak to obtain larger flattening gain bandwidth. The intrinsical gain spectrum is obtained by solving rate and power propagation equations, the effect of transmittance spectrum of thin film filter on flattening gain is discussed.

Simulation of IR Waveguide Amplifiers Using FDTD-Based Overlapping Integral-RK Method

A novel algorithm, calling FDTD-based overlapping integral-RK method, is proposed to analyze Er-Yb co-doped phosphate glass IR waveguide amplifiers. This new method is derived from the combination of Finite-Difference Time-Domain(FDTD), overlapping integral and RK method. First the normalized eigen-fields of signal and pump lights in Er-Yb co-doped phosphate glass waveguide are calculated by FDTD algorithm, and then the overlapping integrals between light fields and the distribution of Er3+(Yb3+) concentrations are obtained, finally the distributions of powers of signal and pump along waveguide are calculated by RK method. Gain performance of IR waveguide amplifiers is obtained from calculated signal power. Comparison of the simulation result with an experiment is given, it demonstrates that this new algorithm is valid and shows good agreement with experimental results.

Modeling and Simulation of Saturation Gain of IR Integrated Photonic Amplifiers

IR integrated photonic amplifiers at 1.55μm operation will have good foreground in optical phased‐array radars for splitters and signal processing. The saturation gain characteristics of IR integrated photonic waveguide amplifiers (taken Er3+‐Yb3+ co-doped phosphate glass waveguide amplifiers as an example) are studied theoretically. For the home‐made laser glass materials the calculated saturation intensities are 2.22kw /cm2 for signal and 10.15kw/cm2 for pump. The effects of absorption saturation of signal and pump lights on the gain of amplifiers are discussed.

High‐gain broadband optical‐waveguide amplifiers

AbstractA novel wideband and high‐gain waveguide‐amplifier structure, which consists of a folded geometry erbium‐ytterbium co‐doped phosphate glass waveguide integrated with a cascaded multilayer medium thin‐film filter (CMMTFF), is proposed. This CMMTFF consists of some different filter‐unit cells with different central wavelengths and bandwidths, and each of them can suppress a certain gain peak at a specific wavelength. The gain characteristics of this new optical amplifiers is obtained. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 64–66, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20208

Er/sup 3+/-Yb/sup 3+/ codoped phosphate glass waveguide amplifier using Ag/sup +/-Li/sup +/ ion exchange

An Er/sup 3+/-Yb/sup 3+/ codoped phosphate glass waveguide amplifier using an Ag/sup +/-Li/sup +/ ion exchange process is demonstrated. The glass contains Li/sup +/ instead of Na/sup +/ and the spectroscopic properties were characterized. The emission parameters were calculated, and the radiative quantum efficiency of the <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> I/sub 13/2/ to <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> I/sub 15/2/ transition is estimated to be /spl sim/100 %. The planar glass waveguide amplifier produces a net gain /spl sim/3.3 dB/cm with an input signal wavelength of 1.535 μm at a power of -40 dBm, for 120 mW of 980-nm pump power.