Erbium-ytterbium Co-doped Fiber Research Articles

Exploring the potential of a bismuth-erbium-vanadium co-doped optical fiber as a stable Q-switcher in the 1550 nm region

This paper experimentally demonstrates the ability of a bismuth-erbium-vanadium co-doped optical fiber as a saturable absorber (BEV-FSA) to generate stable Q-switched pulses in the 1550 nm region. The laser cavity delivered passively Q-switched pulses exploiting an erbium-ytterbium co-doped double-clad fiber (DC-EYDF) as the laser gain medium while maintaining an all-fiber cavity configuration. The output parameters of the laser such as output power, repetition rate, pulse duration, and pulse energy have been studied in detail with the variation of pump power. The output spectrum centered at 1550.86 nm throughout the experiment. The system produced stable pulses with a minimum pulse width of 1.83 µs with a pulse energy≈0.4µJ at the highest pump power of 2.31 W. The highest achievable repetition rate was 47.5 kHz with an of SNR≈53dB.

Q-switched Er-doped fiber laser using an aqueous solution of gold nanorods and polyvinyl alcohol

Authors reported the generation of Q - Switched pulses in an erbium-ytterbium co-doped fiber laser using an aqueous solution of colloidal gold nanorods (GNRs) and Polyvinyl Alcohol (PVA) as a saturable absorber (SA). The effect of the GNRs and PVA concentrations on the pulses has been explored. Passive Q-Switching is achieved at 1.1 W (1.8 A). Pulses with a minimum width of 9.6 µs having a repetition rate of 21.5 kHz and a maximum energy of 0.15 µJ at 1.56 μm are obtained for a pump current of 2.195 W (3.12 A).

High-power, low noise, high gain few-mode fiber amplifier

The few-mode erbium-doped fiber amplifier (FM-EDFA) is a necessary component for high-capacity long-haul mode-division multiplexing (MDM) fiber optic communication systems. In this paper, an all-fiber few-mode amplifier based on erbium-ytterbium co-doped double-clad fiber is designed and demonstrated. We have developed a fiber-optic pump beam combiner and a few-mode isolator. Combined with the two-stage cascade method, an all-fiber few-mode fiber amplifier with high-power, high-gain and low-noise is realized. Simultaneous amplification of 6 modes (LP01, LP11a, LP11b LP21a, LP21b and LP02) are achieved in the 1535–1565 nm range with average modal gain greater than 40 dB, maximum saturated output power up to 29.5 dBm, differential modal gain (DMG) of ∼3 dB and minimum noise figure (NF) of 4.69 dB.

Passive Q-Switching of a Cladding Pumped Erbium–Ytterbium Co-Doped Fiber Laser Induced by the Kerr Effect

Passive Q-Switching of a Cladding Pumped Erbium–Ytterbium Co-Doped Fiber Laser Induced by the Kerr Effect

A passively Q-switched random fiber laser with cascaded doped fiber segments and random phase-shift Bragg grating

In this paper, stable pulse train generated from an all-optical passively Q-switched random fiber laser (RFL) with cascaded doped fiber segments and random phase-shift Bragg grating is demonstrated for the first time. A 25 mm random phase-shifted fiber Bragg grating (RPS-FBG) is used to provide random feedback. Two cascaded doped fiber segments, Erbium-doped fiber (EDF) and Erbium-Ytterbium co-doped fiber (EYDF), are used as saturable absorber when the fibers are incompletely pumped. The characteristics of the RFL under different power of two pump lasers are investigated. The doped fiber has different nonlinearities under different pump power combinations, which results in passively Q-switched pulse with repetition rate from 5.1 kHz to 29.3 kHz. The RFL not only has low-threshold but also exhibits stable random pulse with repetition rate and pulse width controlled by the combination of two pump powers.

10-W random fiber laser based on Er/Yb co-doped fiber

In this study, we presented a 1550-nm, high-power, high-efficiency random fiber laser to improve the output power and slope efficiency of erbium-ytterbium co-doped fiber–based random fiber lasers. By optimizing the length of the erbium-ytterbium co-doped fiber and increasing the 3-dB reflection bandwidth of fiber Bragg grating, the output power and slope efficiency of the random fiber laser were improved. Furthermore, the influence of different fiber lengths on the generation threshold of the amplified spontaneous emission from the Yb3+-ions was studied. An output power of more than 10 W was achieved, with a slope efficiency of 36.7 % and a single transverse mode output. The proposed random fiber laser showed excellent stability in the millisecond scale and long timescale (10 min). The findings of this study can provide a basis for the development of high-performance light sources for a variety of applications.

High-Power Multi-Wavelength Double-Clad Erbium Ytterbium Co-Doped Fiber Laser Using Two-and Four-Mode Fiber Filters

This work demonstrated a multiwavelength erbium-ytterbium co-doped double-clad fiber laser using two- (TMF) and four-mode fibers (FMF) as comb filters. At the maximum pump power of 9 W, the multi-wavelength fiber laser (MWFL) using the TMF filter generated 4 stable lasing lines with a spacing of 0.56 nm. The maximum output power recorded for this setup was as high as 553 mW with a 6.4% slope efficiency. Meanwhile, MWFL uses FMF filter generated 3 lasing lines with a spacing of 0.95 nm. The laser had a maximum output power of 443 mW with a slope efficiency of 5.3%. Both MWFLs were stable when operated for an extended period. The long-term stability test shows that the laser had only small wavelength drifts of 0.21 nm and 0.15 nm using the TMF and FMF filters, respectively. The maximum power fluctuations of the lasing lines were measured to be 2.10 dB for the MWFL using the TMF filter and 2.52 dB using the FMF filter. This work proposed stable high-power MWFL with higher output power and efficiency.

Design Optimization of 12-Core Amplifier Based on Erbium Ytterbium Co-Doped Fiber for Spatial Multiplexed Transmission System

A 20 dB gain 12 cores Er <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3+}$</tex-math></inline-formula> /Yb <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3+}$</tex-math></inline-formula> co-doped cladding pumped amplifier in C-band with only 5.3 W of pump power has been achieved. A classical rate equation model has been applied for the amplifier design. Parameters such as active fiber length, pump power and ions concentration have been investigated and optimized. Results obtained through numerical simulation and experimental investigations are compared. Different use cases of MC-EYDFA have been studied, such as various transmission configuration or multi-core amplifier in ROADM architectures. 1200-km with 200G DP-QPSK and 300 km with 400G DP-16QAM are achieved in serial configuration at 1550 nm. This is a first step towards SDM transmission using power efficient amplifiers, for cost, energy and footprint saving.

Passively high-power Q-switching in Er- and Er/Yb doped fiber with CdTe

In this work, Cadmium Telluride (CdTe) thin-film was demonstrated as a saturable absorber (SA) to induce Q-switching in the erbium-doped fiber laser (EDFL) and erbium-ytterbium co-doped fiber laser (EYDFL) cavities. CdTe thin film was prepared by the liquid-phase exfoliation method and sandwiched between two fiber ferrules to complete the fiberized SA assembly. Firstly, the CdTe-SA was inserted into the EDFL cavity and stable Q-switched pulses were observed at a threshold pump power of 88mW. The shortest pulse width and the highest repetition rate measured for the EDFL cavity were 6.10 ± 0.02 μs and 42.3 ± 1.3 kHz respectively, at a maximum pump power of 295 mW. At a maximum pump power of 295 mW, the highest average output power produced by the Q-switched pulses in the EDFL cavity was 0.15 mW. Meanwhile, Q-switched pulses in the EYDFL cavity self-start at the threshold pump power of 1.4 W. The maximum repetition rate obtained was 99.5 ± 1.5 kHz and a pulse width of 2 μs at a maximum pump power of 3 W. At this pump power, the highest average output power produced by the Q-switched pulses in the EYDFL cavity was 70.0 ± 0.2 mW. This is the first demonstration of a high average power passively Q-switched fiber laser operating in the C-band employing EDF and EYDF as the gain medium and CdTe thin-film as SA that we are aware of.

Erbium-ytterbium co-doped photonic crystal fiber amplifier supporting amplification for orbital angular momentum

In order to reduce the loss in orbital angular momentum (OAM) long-distance communication systems, an OAM erbium-ytterbium co-doped fiber amplifier (OAM-EYDFA) based on photonic crystal fiber (PCF) is proposed and investigated for the first time in this work. We set up a three-dimensional electromagnetic field model of the PCF in Comsol and solved it by the finite element method. Then, we designed a three-dimensional model of the OAM-EYDFA based on the proposed PCF using Comsol and MATLAB. The results reveal that the proposed OAM-EYDFA has a flat-high gain of about 47 dB, a differential mode gain of lower than 0.3 dB and a noise figure of lower than 3.4 dB. Compared with existing studies, its gain is increased by at least 25 dB, and other properties are also improved. The proposed OAM-EYDFA can provide a reference for OAM-based long-distance communication systems.

Fabrication and Laser Performance of Large Mode Area Erbium-Ytterbium Co-Doped Fiber

Fabrication and Laser Performance of Large Mode Area Erbium-Ytterbium Co-Doped Fiber

Output Power of Erbium-Ytterbium Co-Doped Fiber Amplifier After High Temperature Aging

Output Power of Erbium-Ytterbium Co-Doped Fiber Amplifier After High Temperature Aging

Fabrication and Laser Performance of Polarization-Maintaining Erbium-Ytterbium Co-Doped Fiber

Fabrication and Laser Performance of Polarization-Maintaining Erbium-Ytterbium Co-Doped Fiber

Extending the L-band amplification to 1623 nm using Er/Yb/P co-doped phosphosilicate fiber.

The gain bandwidth of the erbium-doped fiber amplifier limits the enhancement of the transmission capacity in optical fiber communication systems. This Letter reports an erbium-ytterbium co-doped phosphosilicate fiber, which is expected to increase transmission capacity by extending the L-band gain bandwidth to 1623 nm. The fiber was fabricated by modified chemical vapor deposition combined with solution doping technology. The mechanism of bandwidth-expansion by inhibiting the signal excited-state absorption was investigated. When the signal power and pump power were maintained at -3.7dBm and ∼720mW at 1480 nm, the 20 dB gain range was extended out to 1623 nm. Additionally, the noise figure at 1623 nm decreased to 6.01 dB, with 23 dBm saturated output power. The results show that the erbium-ytterbium co-doped phosphosilicate fiber has a great potential for extending L-band amplification.

Yb-ASE Suppression in Single-Frequency Hybrid Double Cladding Erbium–Ytterbium Co-Doped Fiber Amplifier with SMS Structure

A hybrid double cladding erbium–ytterbium co-doped fiber (EYDF) amplifier with a single-mode-multimode-single-mode (SMS) active fiber is demonstrated in this study. The hybrid gain fiber with an SMS structure is composed of two kinds of EYDFs with 6 and 12 μm core diameters. The transmission spectra of the SMS fiber structure were theoretically analyzed and the simulation results indicated that the maximum loss in the 1~1.1 μm band where the Yb-band amplified spontaneous emission (Yb-ASE) located, was much larger than that of the 1.5-μm band because of the wavelength difference. The power performance and spectra properties of the hybrid fiber amplifier were theoretically and experimentally analyzed and compared with a typical uniform fiber amplifier under the same conditions. The experimental results demonstrated that this hybrid fiber amplifier can suppress the Yb-ASE by over 12 dB and increase the slope efficiency by more than 2%, but the ASE in the 1.5-μm band increases by 2~3 dB. This work provides a possible method to enable EYDF amplifiers to suppress the Yb-ASE and overcome the pump bottleneck effect.

A Comparative Study of SPM and XPM in Er-Yb Co-Doped Fiber

Optical fiber communication has been the most versatile and revolutionary medium of communication that has helped connect millions of people across the globe. These traits have seen tremendous development in the sector of optical fiber communication. There are now many desired qualities expected out of an optical fiber communication such as large transmission capacity and a smaller amount of loss. Communication systems operating with higher transmission rates have found an essential role of non-linear fiber optics. The behavior of light in non-linear media is described by non-linear optics. Cross-phase modulation (XPM) and self-phase modulation (SPM) are a few non-linearities occurring in the optical fiber. Non-linear effects reduce the performance of optical fibers. In this paper, a comparative study of non-linear effects in erbium-ytterbium co-doped fiber is reviewed using simulation. The results are compared with optical systems utilizing normal fiber. The benefits of using Er-Yb fiber have been demonstrated by analyzing effective systems comprising the Er-Yb co-doped fiber and their ability to mitigate the non-linearities.

Bose-Einstein condensation of photons in a long fiber cavity.

We demonstrate photon Bose-Einstein condensation (photon-BEC) at a broad temperature range that is valid also in the long 1D fiber cavity limit. It is done with an erbium-ytterbium co-doped fiber (EYDF) cavity by overcoming the challenging requirement of sublinear light dispersion for BEC in 1D using a chirped-gratings Fabry-Perot. We experimentally show with a square-root mode-dispersion, a quadratic temperature dependence of the critical power for condensation (compared to a linear dependence in finite regular fiber-cavities) between 90 K and 382 K, as the theory predicts.

Passively Q-switched fiber laser with single and double wavelength switching based on parallel FBGs

We proposed a passively Q-switched fiber laser with switchable wavelength based on two parallel fiber Bragg gratings. By increasing the input power, a single wavelength with a center wavelength of 1545.63 nm and dual wavelengths with a center wavelength of 1545.63 nm and 1553.60 nm can be obtained respectively. The wavelength spacing of the dual wavelengths is 8.17 nm, and the maximum repetition frequency of Q-switching is 24.27 kHz, and the narrowest pulse width is 5.48 ms. The combination of parallel fiber grating and erbium-ytterbium co-doped fiber (EYDF) saturable absorber provides a simple and feasible method to obtain stable (single and double wavelength switching) passively Q-switched pulses.

Experimental Research on High Power Cascade Co-pumping Erbium-Ytterbium Co-doped Fiber Laser

Experimental Research on High Power Cascade Co-pumping Erbium-Ytterbium Co-doped Fiber Laser

Characterization of multi-wavelength Q-switched fiber laser by changing wavelength separation of filter

Abstract In this paper, we present a simple compact and low threshold laser that has characteristics of Q-switched and multi-wavelength oscillation simultaneously. Multi-wavelength Q-switched oscillation is realized by inserting a Sagnac filter as a multi-wavelength filter and a section of unpumped erbium-ytterbium co-doped fiber (EYDF) into the laser cavity as a saturable absorber (SA). The characteristics of multi-wavelength Q-switched fiber laser affected by wavelength separation of filter and pump power are investigated. The number of Q-switched wavelengths increases and the wavelength separation of the laser reduces with wavelength separation of the filter decreasing. Stable multi-wavelength oscillations at wavelength separation of 0.4–0.8 nm were obtained by increasing the length of polarization maintaining fiber (PMF) in the Sagnac filter. Moreover, the number of wavelengths and wavelength separation are increased by increasing the pump power when the filter is fixed. Further, the multi-wavelength laser is verified to have Q-switched properties at each wavelength, which is filtered from laser output through a narrow-band tunable filter outside of the cavity.