- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Oxidation-resistance Black Phosphorus Enable Highly Ambient-stable Ultrafast Pulse Generation at 2 μm Tm/Ho-doped Fiber Laser
摘要： Black phosphorus (BP) ranks among the most promising saturable absorber materials for ultrafast pulse generations at 2 μm. However, the easy-to-degrade characteristic of BP seriously limits the long-term operation of ultrafast fiber lasers and hence becomes a bottleneck for its relevant practical applications. In this paper, a modified electrochemical delamination exfoliation process was explored to produce high-performance, large-size and oxidation-resistance BP nanosheets, where BP nanosheets in high yield with evenly coated tetra-n-butyl-ammonium (TBA) organics by precisely controlling the intercalation chemistry can be obtained. A mode-locked Tm/Ho co-doped fiber laser with high temporal stability and long-term operation capability was demonstrated based on the innovatively-fabricated BP saturable absorber. The self-starting mode-locking operation featuring high signal-to-noise ratio of 58 dB and long-term stability has been verified for at least three weeks, which indicates the successful passivation of the employed synthesis method. These results fully indicated that passivated BP is an efficient candidate in 2 μm range ultrafast photonics field, which will promote the ultrafast optical application of BP and also other infrared photonic and photoelectronic devices.
关键词： mode-locked laser,2D materials,fiber laser,mid-infrared,black phosphorus
更新于2025-09-12 10:27:22
-
[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) - Passively Mode-Locked Self-Frequency Doubling Yb:LGSB Laser
摘要： Non-centrosymmetric crystals exploited as host matrices for rare earth active ions simultaneously enable a self-frequency doubling (SFD) process. In case of ytterbium doping it allows to obtain laser radiation at 1 μm and its SFD signal covering green spectral range. This mechanism is particularly interesting in case of mode-locked oscillators as the intensity within the crystal is much higher, thus increasing the conversion efficiency. Moreover, it can be also employed for cascaded χ(2) processes. Nevertheless, despite more than 20 years of development of Yb-doped mode-locked bulk lasers there are very few demonstrations of femtosecond oscillators with SFD properties [1-3]. One of the recently introduced non-centrosymmetric Yb3+-doped active media is LaxGdyYbzScw(BO3)4 (x + y + z + w = 4; shortly Yb:LGSB) crystal [4,5]. This novel scandium borate compound is a negative uniaxial crystal and it exhibits strong second order nonlinearity (point group 32). The nonlinear coefficient d11 amounts to 2.1 pm/V, which is much higher than in case of previously investigated SFD crystals [1-3]. Moreover, its emission spectrum is relatively broad and thus it is a very promising candidate for femtosecond SFD, which, to the best of our knowledge, has never been demonstrated with this gain medium before. Here, we demonstrate the first mode-locked operation of a laser based on an Yb:LGSB gain medium. The scheme of the X-shaped resonator cavity is depicted in Fig. 1a. An investigated c-cut 2.55 mm-long La0.681Gd0.308Yb0.129Sc2.882(BO3)4. crystal was grown by Czochralski method [4]. It was pumped by a 1 W fiber-coupled single-mode laser diode with central wavelength of 979 nm. Due to lack of the AR-coatings it was inclined under Brewster’s angle. As a saturable absorber we used a semiconductor saturable absorber mirror (SESAM) with 0.6% modulation depth and 10 ps relaxation time. In order to obtain stable soliton mode-locked operation the anomalous dispersion of -1650 fs2 was introduced to the cavity by the Gires-Tournois-interferometer (GTI) mirrors. The output coupler transmission was 0.8%. In this configuration the laser emitted 6.8 nm broad spectrum centered at 1070 nm (Fig. 1b), which corresponds to transform-limited pulse duration of 180 fs. The output average power was equal to 32 mW with repetition rate of 89 MHz. During mode-locked operation we could also observe a self-frequency doubled signal. Due to the low reflectivity of the employed mirrors in the green, the strongest SFD signal was detected after one of folding mirrors. The second harmonic spectrum is shown in the inset of the Fig. 1b. The fringes originate from the fact that SFD was not phase-matched in this case [3]. The work was supported by National Science Centre (NCN, Poland; grant 2015/18/E/ST7/00296) and by Ministry of Research and Innovation of Romania (CNCS-UEFISCDI, grant PN-III-P4-ID-PCE-2016-0853 within PNCDI III).
关键词： Yb:LGSB,mode-locked laser,non-centrosymmetric crystals,femtosecond oscillator,self-frequency doubling
更新于2025-09-12 10:27:22
-
[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) - Femtosecond-Driven Up-Conversion in a Radially Poled LiNbO <sub/>3</sub> Microresonator
摘要： Nowadays, there are plenty of different techniques developed for the generation of Optical Frequency Combs (OFCs), but Mode Locked Laser (MLL) OFC is still the most commonly used and commercially available one [1]. Although MLLs are capable of producing very high-peak power OFCs with femtosecond pulse durations, it is sometimes challenging to apply them directly for a number of reasons. First, MLLs typically produce OFCs with repetition frequencies (fr) below 1 GHz, so additional filtering of the unwanted modes is required for the applications in telecommunications, astrocombs etc. Second, many spectral regions – namely mid-infrared, visible and ultraviolet – are difficult to access by MLLs, which implies the use of external parametric up- and down-conversion. One promising platform for such spectral transfer is high Q-factor optical microresonators based on second order (χ(2)) nonlinear crystals, since not only do they provide the desired spectral transfer, but also open up opportunities for the miniaturization of the system. In addition, such microresonators support whispering gallery modes that possess very low mode volumes, making it possible to enhance nonlinear (χ(2)) processes. This is a significant advantage over the already existing bulk analogs.
关键词： Mode Locked Laser,microresonators,second harmonic generation,femtosecond pulses,Optical Frequency Combs
更新于2025-09-12 10:27:22
-
[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) - Thermally Stabilized, Energy Efficient, All-Fiber Optical Frequency Comb
摘要： In recent years, optical frequency combs are gaining attention in many fields of science, e.g. frequency metrology, optical clocks, and high-resolution spectroscopy. Most sophisticated comb sources can be repetition rate stabilized down to 10-16 uncertainty in 1 s averaging time [1] (bounded by the stability of the reference clock). Therefore compact, low-cost and energy efficient fiber-based sources are highly demanded on the market [2]. Accurate thermal stabilization of the fiber laser cavity is the first step to obtain stable repetition frequency, which is critical for optical frequency comb spectroscopy schemes [3]. Moreover, cavity-enhanced spectroscopic techniques like Vernier spectroscopy requires additional detuning of the comb repetition rate from the cavity mode-spacing [4]. We report an experimental investigation of the performance of a Er-doped, low power, thermally stabilized, mode locked laser, utilizing graphene as a saturable absorber. The oscillator, depicted in Figure 1(a), consists of: a hybrid component comprising an output coupler, wavelength division multiplexer and isolator (TIWDM), saturable absorber, and a piezo-electric transducer (PZT). The laser based only on polarization maintaining (PM) fibers, without any free space components. The entire resonator and all components are placed on a custom-made heating plate with uniformly spread heating traces, which equally cover the entire board surface, ensuring perfectly homogenous heat distribution. For efficient thermal stabilization, the fibers are attached to the plate by acrylic adhesive thermopads. The resonator is placed in a 3D-printed enclosure. A custom-made thermal controller is responsible for thermalization of all oscillator components with long term stability better than 0.05°C. Additional tuning of the repetition rate in the range of 0 – 2.79 kHz is performed by means of a piezo stretcher driven with voltages from 0 to 150 V. The stretcher is based on a miniature, monolithic, multilayer piezo stack (5x5x50 mm), which stretches the Er-doped fiber by approximately 36 μm. The fundamental repetition rate (fc), resulting from the cavity length is equal to 124.6539196 MHz at 30°C (without any voltage applied to the PZT). The signal to noise ratio (SNR) in the radio frequency (RF) spectrum measured with 2.7 Hz resolution bandwidth (RBW) is at the level of 70 dB. The repetition rate of the laser can be detuned by 17 kHz via heating the resonator from 30 to 50°C. We believe that such compact, simple frequency combs with low power consumption are suitable for field applications. The presented work was funded by the Foundation for Polish Science (First TEAM/2017-4/39) co-financed by the European Union under the European Regional Development Fund. A.G. acknowledges the support of the Faculty of Electronics (grant “M?oda Kadra”).
关键词： optical frequency combs,fiber stretcher,thermal stabilization,graphene saturable absorber,mode locked laser
更新于2025-09-12 10:27:22
-
Noise-Like Pulse Generation Using Polarization Maintaining Mode-Locked Thulium-Doped Fiber Laser With Nonlinear Amplifying Loop Mirror
摘要： We investigate noise-like pulse (NLP) generation in a mode-locked thulium-doped fiber laser with nonlinear amplifying loop mirror (NALM) and different net anomalous dispersions. The all-polarization maintaining (PM) fiber oscillator generates pulse trains with a frequency adjustable in the range of 4.06–20.4 MHz by utilizing different lengths of PM passive fiber in the NALM loop. An NLP with a coherence spike width of 232 fs was generated at 1993.6 nm with a 3-dB spectral width of 32.6 nm when the net cavity dispersion was ?0.711 ps2.
关键词： thulium-doped fiber,mode-locked laser,NALM,fiber laser,noise-like generation
更新于2025-09-11 14:15:04
-
All-Fiber Dual-Wavelength Mode-Locked Laser Using a Bend-Induced-Birefringence Lyot-Filter as Gain-Tilt Equalizer
摘要： Multi-wavelength ?ber lasers have emerged as a promising light source for the application in wavelength division multiplexing communication, terahertz wave generation and optical sensing due to high ef?ciency and robustness. Lyot-?lter emerges as a potential device for multi-wavelength generation application. However, because of the high birefringence of polarization maintaining ?ber in Lyot-?lter, it is dif?cult to generate broadband dual-wavelength or multi-wavelength mode-locked ?ber laser by using common Lyot-?lter. In this paper, for the ?rst time, we propose an idea of using the low birefringence induced by bending the single-mode ?ber to form a Lyot-?lter for dual-wavelength mode-locked ?ber laser generation. The dual-wavelength output centers at 1532 and 1556 nm and it may simplify the set-up for dual-wavelength mode-locked laser.
关键词： ?ber lasers.,Mode-locked laser
更新于2025-09-11 14:15:04
-
Ultrafast mode-locked fiber laser with Zirconium disulfide on D-shaped Fiber
摘要： Transition-metal dichalcogenides (TMDs), as highly anisotropic layered compounds, have attracted increasing interest from basic research to practical applications. Among them, zirconium disulfide (ZrS2) with remarkable physical properties has been widely investigated recently. Here, ZrS2 employed as a saturable absorber is utilized in an Er-doped fiber laser. A stable mode-locking operation is achieved, with central wavelength of ~1559.5 nm, 3 dB bandwidth of ~1.72 nm, and pulse duration of ~1.75 ps. These results make ZrS2 an appealing candidate for generating ultrafast laser pulses.
关键词： Mode-locked,Laser,Solitons
更新于2025-09-11 14:15:04
-
Microring resonator-based photonic system for terahertz signal generation
摘要： We propose a photonic system based on add–drop microring resonator and mode-locked laser for terahertz (THz) signal generation. A mode-locked laser acts as an input source to the microring resonator. The transfer characteristics of the microring resonator generate Lorentzian shaped pulses at the output ports of the microring resonator. These series of pulses obtained are then investigated in two approaches; in the ?rst approach, the output of the microring resonator is given to a photodetector which generates 33 THz pulses separated by a spacing of 1 THz with a full width at half maximum (FWHM) of 0.15 THz. In the second approach, the output of the microring resonator is given to an optical ?lter to extract a particular frequency component. In this case, a single THz carrier with a FWHM of 0.2618 THz is obtained. The THz frequency components generated by the proposed photonic system can act as carriers for communication between the indoor user and the base station of a pico/femto cell in a 5G environment.
关键词： THz signal generation,Microwave photonics,Microring resonator,Frequency comb generation,Mode-locked laser
更新于2025-09-10 09:29:36