- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Single-Pass Laser Frequency Conversion to 780.2 nm and 852.3 nm Based on PPMgO:LN Bulk Crystals and Diode-Laser-Seeded Fiber Amplifiers
摘要： We report the preparation of a 780.2 nm and 852.3 nm laser device based on single-pass periodically poled magnesium-oxide-doped lithium niobate (PPMgO:LN) bulk crystals and diode-laser-seeded fiber amplifiers. First, a single-frequency continuously tunable 780.2 nm laser of more than 600 mW from second-harmonic generation (SHG) by a 1560.5 nm laser can be achieved. Then, a 250 mW light at 852.3 nm is generated and achieves an overall conversion efficiency of 4.1% from sum-frequency generation (SFG) by mixing the 1560.5 nm and 1878.0 nm lasers. The continuously tunable range of 780.2 nm and 852.3 nm are at least 6.8 GHz and 9.2 GHz. By employing this laser system, we can conveniently perform laser cooling, trapping and manipulating both rubidium (Rb) and cesium (Cs) atoms simultaneously. This system has promising applications in a cold atoms Rb-Cs two-component interferemeter and in the formation of the RbCs dimer by the photoassociation of cold Rb and Cs atoms confined in a magneto-optical trap.
关键词： single-pass sum-frequency generation,fiber amplifier,rubidium D2 line (780.2 nm),single-pass second-harmonic generation,cesium D2 line (852.3 nm)
更新于2025-09-16 10:30:52
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Simulation of optical fiber amplifier gain using equivalent short fibers
摘要： Electromagnetic wave propagation in optical fiber amplifiers obeys Maxwell equations. Using coupled mode theory, the full Maxwell system within an optical fiber amplifier is reduced to a simpler model. The simpler model is made more efficient through a new scale model, referred to as an equivalent short fiber, which captures some of the essential characteristics of a longer fiber. The equivalent short fiber can be viewed as a fiber made using artificial (unphysical) material properties that in some sense compensates for its reduced length. The computations can be accelerated by a factor approximately equal to the ratio of the original length to the reduced length of the equivalent fiber. Computations using models of two commercially available fibers – one doped with ytterbium, and the other with thulium – show the practical utility of the concept. Extensive numerical studies are conducted to assess when the equivalent short fiber model is useful and when it is not.
关键词： Scale model,Ytterbium,Thulium,Laser gain,Fiber amplifier
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Compact One-Octave Spanning Supercontinuum Generation by Amplification of Noise like Pulses in Yb-Doped Fiber Amplifier
摘要： Currently, supercontinuum source has found wide applications in different area of science and technology. Optical frequency meteorology [1], spectroscopy [2], optical coherence tomography [3] and high-speed optical communication [4] are among the most prominent application of supercontinuum light sources. Recently, using noise like pulses(NLPs) for generating supercontinuum sources have attracted attention [5,6]. In this work, we demonstrate a high power broad supercontinuum source by amplifying NLPs in fiber amplifier in the nonlinear regime.
关键词： nonlinear regime,Yb-doped fiber amplifier,noise like pulses,supercontinuum generation
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Tm-Doped Nonlinear Fiber Amplifier Emitting 50 fs Pulses and 20 W of Average Power at 2 μm Wavelength
摘要： Tm-doped fiber lasers with an emission wavelength around 2 μm have drawn increasing attention for applications in fundamental and life sciences. It has recently been identified, that the utilization of long wavelength drivers is beneficial for the parametric downconversion into the molecular fingerprint region (2-20 μm wavelength), since they can effectively use conveniently available non-oxide crystals with high conversion efficiency to address the wavelength region beyond 5 μm, which is difficult with today’s well matured 1 μm drivers. Transferring these results into an application driven context in medical and life sciences requires a compact design and flexibility of the driving source to serve a huge audience. Addressing the mid infrared fingerprint region via parametric downconversion requires both, short pulses and moderate peak power to ensure a good spectral coverage. To fulfill these requirements chirped pulse amplifiers use bulky post compression schemes, which makes them not well suited for this field of application. In this work we propose a nonlinear fiber amplifier, which has the potential to drastically shrink the footprint of the driving source, by combining both compression and amplification in a single fiber. This will ultimately enable for high-power shoebox size laser sources in the molecular fingerprint region.
关键词： molecular fingerprint region,nonlinear fiber amplifier,parametric downconversion,Tm-doped fiber lasers
更新于2025-09-11 14:15:04
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[IEEE 2019 SBFoton International Optics and Photonics Conference (SBFoton IOPC) - Sao Paulo, Brazil (2019.10.7-2019.10.9)] 2019 SBFoton International Optics and Photonics Conference (SBFoton IOPC) - Few-Mode Erbium-Doped Fiber Amplifier Design Challenges for WDM Optical Networks
摘要： The use of optical spatial division multiplexing (SDM) technologies increases the capacity of the optical channel, allowing higher transmission rates than those observed in wavelength division multiplexing (WDM) optical systems based on single-mode fibers. In particular, spatial multiplexing based on multimode fibers allows the transmission of information in orthogonal modes. In these systems, the erbium-doped fiber amplifier (EDFA) remains essential to compensate for optical link losses. This paper presents the challenges to the development of EDFAs for WDM optical systems based on few-mode fibers, considering the addition of gain flattening filters and correction of gain calculation.
关键词： erbium-doped fiber amplifiers,space division multiplexing,gain equalization,Few-mode fiber amplifier
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Ultrafast Tm-Doped Fiber Amplifier with 1 kW Average Output Power
摘要： Ultrafast thulium-doped fiber lasers emitting in the 2 μm wavelength region have recently attracted a significant amount of attention regarding applications in material processing, life sciences, as well as in fundamental science, e.g. high harmonic generation, particle acceleration, mid-IR generation. In addition to the application-relevant emission wavelength, Tm-doped silica fibers possess many interesting characteristics, such as a broad gain bandwidth spanning from 1700 nm to 2100 nm and more than 70% slope efficiency by exploiting cross-relaxation processes. Furthermore, the longer operation wavelength reduces the impact of detrimental nonlinear effects in fiber lasers, and allows for a larger mode field area with diffraction-limited beam quality as compared to the well-established ytterbium-doped fiber laser systems. In this contribution, we report on a new average power record from a thulium-doped fiber amplifier. We use state-of-the-art laser diodes to reach a combined pump power of more than 2 kW at 793 nm. The use of a polarization maintaining thulium-doped photonic crystal fiber allows for an optical-to-optical efficiency of more than 60% and a pump-limited average output power of 1150 W. After compression to 265 fs pulse duration, 1060 W of average power and 50 MW of peak power at 80 MHz pulse repetition rate are achieved, which represents a performance level that is currently not achievable with a single ultrafast ytterbium-doped fiber amplifier. Additionally, we confirmed a close to diffraction-limited beam quality (M2<1.1) up to the highest power level. From the simulation of the amplification process, the average heat-load of the fiber reaches 95 W/m at full power level, without the onset of transverse mode instability. This average heat-load is significantly higher than the critical value of about 30 W/m, which was found to be the threshold for transverse mode instability in ytterbium-doped fiber lasers.
关键词： ultrafast,high power,Tm-doped fiber amplifier,photonic crystal fiber
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Atmospheric CO <sub/>2</sub> -Detection Via Scheimpflug DIAL Employing a Simple Fiber Amplifier
摘要： The ever-increasing worldwide environmental awareness has prompted much effort to minimize humanity’s ecological footprint. This has led to increased demands for reliable technologies for assessing the current situation as well as the efficiency of new policies and interventions. In particular, CO2-monitoring has attracted lots of attention as CO2 is the greenhouse gas that is emitted in the largest quantities. Differential absorption light detection and ranging (DIAL) is a well-established method for measuring the atmospheric CO2-concentration. Conventional implementations of this method rely on tunable pulsed laser sources whose back-scattering at different distances are compared for different wavelengths, corresponding to being on and off the CO2-resonances, to calculate the concentration along the measured path. Integrating these types of laser sources with DIAL systems have proven to be complicated and often suffer from instabilities. Therefore, a continuous-wave DIAL (CW-DIAL) scheme was recently proposed that relates signals at different distances to different points on a detector by using a Scheimpflug configuration. This technique relies on a rapidly tunable, narrow-linewidth source to resolve individual CO2-absorption lines, making distributed feedback laser diodes (DFB) ideal. However, they lack the necessary power levels for ranging over relevant distances, usually in the km-range. We therefore designed a fiber amplifier, based on an 11 m Er-/Yb-doped fiber, to boost the power level to about 1.3 W. The output was then expanded by a telescope and the back-scattered signal was collected by a second telescope, as schematically illustrated in Fig. 1 (a). The wavelengths could be tuned about 3 nm with a 35 dB signal-to-noise ratio, as shown in Fig. 1 (b), by adjusting the driving current to the DFB, while keeping a linewidth of about 3 MHz –well below the CO2-linewidth around 1 GHz at normal pressure. The system was used to measure the atmospheric CO2-concentration above the city of Lund, Sweden, over a 15 hour period. Using the backscattered data from 48 different wavelengths over the R14, R16 and R18 absorption peaks, the range-resolved concentration, illustrated in Fig. 1 (c) with a 500 m bin discretization, could be retrieved. The large increase in the error at the final concentration bin is related to the nonlinear range mapping onto the detector, i.e. fewer pixels for greater distances. Regardless, these results show that our simple fiber source already fulfills the necessary requirements for field application of CW-DIAL.
关键词： atmospheric CO2-concentration,DIAL,fiber amplifier,Scheimpflug configuration,CO2-monitoring
更新于2025-09-11 14:15:04
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[IEEE 2018 IEEE 7th International Conference on Photonics (ICP) - Langkawi, Malaysia (2018.4.9-2018.4.11)] 2018 IEEE 7th International Conference on Photonics (ICP) - Influence of Raman Pump Direction on the Performance of Serial Hybrid Fiber Amplifier in C+L-Band
摘要： This study demonstrates the simulation and experimental validation of a serial hybrid Raman/erbium-doped fiber amplifier in the C+L optical communication bands. The erbium-doped fiber is pumped by the residual Raman pump to enhance pump conversion efficiency in forward (Type A) and backward (Type B) direction. The amplifier was tested with three different input levels where the overall finding shows Type B provides better gain (average of 20dB across band) than Type A at the expense of noise figure (2dB higher).
关键词： serial hybrid fiber amplifier,recycling technique,conventional technique
更新于2025-09-10 09:29:36
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Thermal Effects on Modal Properties of Dual-Core Yb-Doped Fibers
摘要： The impact of thermo-optic refractive-index changes arising from the core heat load in a dual-core fiber amplifier is studied through finite-element based numerical simulations. Trends in coupling lengths, effective area, core overlaps of fundamental and higher-order supermodes, effects of asymmetric heat loads, and thermo-optic mode coupling parameters are quantified. It is concluded that the coupling between cores is only moderately altered by the overall heat load, but can be strongly sensitive to asymmetric loads. The influence of the core coupling strength is demonstrated to be very important on the supermode effective area, besides the shrinking due to thermal effects. While the thermo-optic index perturbations can lead to guidance of higher-order supermodes, it seems realistic to maintain single-mode operation through gain suppression of the higher-order modes. On the other hand, thermo-optic couplings between fundamental supermodes are found to be quite strong.
关键词： dual-core fiber,fiber amplifier,supermodes,thermo-optic,thermal effects
更新于2025-09-04 15:30:14
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5?W 1952?nm Brillouin-free efficient single clad TDFA
摘要： We report the performance of a two stage single clad (SC) Thulium-doped fiber amplifier (TDFA), delivering an output power of 5 W at 1952 nm without stimulated Brillouin scattering (SBS) for a single-frequency input signal. A slope efficiency greater than 60%, a signal gain greater than 60 dB and an input dynamic range > 30 dB were achieved. The amplifier topology was optimized with a simulation tool, experimental results and simulations are in good agreement.
关键词： Multistage,Single-frequency,Brillouin,Single clad,Fiber amplifier,Simulation,Thulium
更新于2025-09-04 15:30:14