This work demonstrates a high-efficiency, intrinsically triggered vertical photoconductive semiconductor switch using 355 nm laser excitation. The key is a zero-electrode-offset design where the electrode edges are aligned flush with the laser-incident sidewall. This geometry maximizes the effective contact area for collecting photogenerated carriers confined within a shallow (similar to 50 mu m) surface layer, enabling efficient current spreading. Compared to a conventional planar structure, the optimized vertical device achieves over an order-of-magnitude reduction in on-state resistance at high optical intensity, reaching a remarkably low saturated resistance of 0.5 Omega at 10 MW/cm(2). This performance surpasses that of extrinsically triggered vertical devices and advanced planar devices with n(+) implantation, while operating at significantly lower optical intensity and without requiring complex doping processes. The results validate a promising strategy that combines the benefits of intrinsic triggering (high efficiency) and vertical architecture (robust current handling) for developing high-voltage, high-power pulsed electronics.

We present a high-energy thulium-doped fiber laser with an all-polarization-maintaining (all-PM) design, which produces narrow-bandwidth dissipative soliton resonance (DSR) pulses in the normal-dispersion regime. The seed source is based on a nonlinear amplifying loop mirror (NALM). Stable DSR pulses are obtained through proper dispersion and nonlinear control with the use of PM2000D fiber for dispersion compensation. The oscillator operates at 6.371 MHz, with the output centered at 1944 nm and a 3-dB bandwidth of 0.41 nm. To further scale the pulse energy and output level, a two-stage all-PM master oscillator power amplifier (MOPA) scheme is employed. With this design, the system delivers up to 13.7 W of average power and 2.2 μJ of pulse energy, while the 3-dB spectral bandwidth remains as narrow as 0.98 nm. This work demonstrates the energy scaling of a narrow-bandwidth all-PM thulium-doped DSR fiber laser in the normal-dispersion regime, achieving μJ-level narrow-bandwidth DSR pulse generation. The all-PM configuration effectively suppresses polarization drift induced by environmental perturbations, thereby ensuring long-term stability and repeatability. Such high-power, narrow-bandwidth, linearly polarized DSR pulses are promising for applications in mid-infrared nonlinear optics, frequency conversion, and optical parametric oscillators (OPOs).

We analyzed the advantages of phosphorus-doped fiber (PDF) in flat supercontinuum (SC) generation via theoretical simulations and realized hundred-watt-level flat SC based on PDF. Based on the generalized nonlinear Schro & uml;dinger equation and the Raman response function of PDF, we simulate the process of SC generation in PDF. Meanwhile, a main oscillator power amplifier (MOPA) structure was employed to pump a home-made PDF. In the experiment, a SC source with an output power of 108.9 W and a spectrum ranging from 755 nm to 2230 nm within a 10 dB level is demonstrated. To the best of our knowledge, this is the first simulation of the SC generation process in PDF and achieving a flat SC output based on PDF at hundred-watt level in experiment.

Fiber-based supercontinuum offer broad spectral bandwidth,high brightness,and excellent spatial coherence,showing great promise in applications such as electro-optical countermeasures,gas sensing,and optical coherence tomography.To address the diverse performance requirements of supercontinuum imposed by different application scenarios,this paper reviewed recent advances in three key directions of fiber-based supercontinuum:power scaling,long wave extension,and low noise research.The technical approaches tailored to enhance each specific performance metric were summarized,and an outlook on future developments was provided,aiming to serve as a reference for the development and application of high-performance supercontinuum.

Customized temporal shaping has greatly enhanced the application effect of high-energy nanosecond pulsed lasers. We reveal for the first time the divisibility of temporal shaping in nanosecond pulsed fiber amplifiers through comprehensive theoretical simulation and experimental verification. Multi-format nanosecond pulsed fiber amplifiers with equal cumulative pulse widths can share a unified pre-compensation design to achieve a class of equivalent temporal envelope shaping, which presents a new one-to-many correspondence. Our research will provide key support for flexible multi-format switching of high-energy nanosecond pulsed lasers.

Microwave sources are central to modern technologies ranging from radar and directed energy to medical applications, yet conventional electronic approaches face long-standing trade-offs between output power and tunability. Optoelectronic techniques offer a promising alternative by combining the broad bandwidth of optical systems with the high power-handling capability of wide-bandgap semiconductors. Here we show an optoelectronic microwave source based on fast-response silicon carbide, enabling picosecond-scale control of photogenerated carrier lifetime while sustaining power-handling capacities up to 55 MW. The system generates continuously tunable pulsed microwave emission across the P-L band, delivering peak output power exceeding 1 MW over the 0.25-1.3 GHz range and exhibiting stable nanosecond-scale pulse operation. The generated pulses exhibit low timing jitter and highly efficient power combining in array operation. These results demonstrate a scalable route toward high-power, broadband, and flexible microwave sources, enabling applications that demand simultaneous control over frequency, energy, and spatial distribution.

Dual-wavelength pumping based on cross-phase modulation (XPM) has been experimentally demonstrated to generate broadband, flat supercontinuum (SC) in fiber, but the role of pump pulse width remains unclear. Here, we experimentally and numerically study the propagation dynamics in XPM-assisted dual-wavelength pumping to clarify both the spectral-flattening mechanism and the influence of pulse width. The results show that XPM lowers the modulation-instability (MI) threshold of the 1550 nm pulse, while the resulting MI sidebands are transferred to the 1030 nm pulse through XPM coupling, promoting pulse break-up and subsequent intrapulse Raman scattering at 1030 nm. This process mitigates pronounced cascaded Raman peaks and favors smooth broadband spectrum generation. The pulse width of dual-wavelength pumping determines the effective XPM interaction window and thus the fraction of 1030 nm pulse energy involved in XPM-induced modulation. Consequently, spectral flatness is governed by a trade-off between increasing temporal overlap and maintaining sufficient pulse energy for efficient spectral broadening, leading to an optimal pulse-width pairing. These results provide practical guidance for optimizing flat SC generation in dual-wavelength fiber pumping and offer further insight into the coupled nonlinear dynamics in optical fibers.

We present an experimental investigation on hectowatt-level beam self-cleaning and the generation of supercontinuum (SC) by pumping a long multimode double-clad taper passive fiber (MM-DTF) with a high-power, allfiber-structured pulsed laser amplifier. To enhance the output power and beam quality, the coiling diameter of the main amplifier Yb-doped fiber in the pulsed laser amplification system was optimized. When the seed pulse width is 4.8 ns and the repetition rate is 5 MHz, the MM-DTF compatible with the gain fiber is spliced with the amplifier stage to enable a broadband supercontinuum with an output power of 261 W and a spectral range from 800 nm to 2200 nm. At various output powers, the beam quality factor (M2) at 1064 nm was measured, and the Beam Self - Cleaning (BSC) phenomenon was observed. The beam quality factor at the output end of the MM-DTF is improved from 1.75 to 1.29. This result demonstrates a practical route for accessing the high-power and highbeam quality SC in highly multimode MM-DTF.

A 50.9-W all-fiber mid-infrared (MIR) supercontinuum (SC) laser with a conversion efficiency of over 76.7% is demonstrated in a ZBLAN (ZrF4–BaF2–LaF3–AlF3–NaF) fiber. The entire system consists of a broadband thulium-doped fiber amplifier (TDFA) operating at 1.9–2.6 μm and a piece of ZBLAN fiber. The system features an all-fiber architecture, which is achieved by directly splicing the pigtail fiber of the TDFA to the ZBLAN fiber. The system’s stability and reliability were ensured by the utilization of the water-cooled fusion splicing joint between the silica fiber and ZBLAN fiber, and an AlF3 fiber endcap. When the seed pulse repetition rate (PRR) was 3 MHz and the pulse duration was 6 ns, a MIR SC laser with an average power of 50.9 W and a spectral range of 1.9–3.6 μm was obtained, with a corresponding power conversion efficiency (from the TDFA output to the SC laser output) of 76.7%. By adjusting the pulse duration to 4 ns, the generated SC laser exhibited a spectral range of 1.9–3.7 μm and an average power of 50.1 W, corresponding to a power conversion efficiency of 75.1%. Such a supercontinuum (SC) laser paves the way for the application of high-power SC lasers in a wide range of fields.

Microwave sources are widely employed in communication, radar, and directed energy systems. However, conventional microwave sources based on electronic techniques often struggle to balance multi-parameter tunability and high output power, thereby limiting their application scope. To overcome this limitation, this study integrates optoelectronic approaches into microwave source systems, leveraging the broad bandwidth of lasers and the high power-handling capabilities of wide-bandgap semiconductors. In the proposed optoelectronic microwave source (OEMS), fast-response silicon carbide (SiC) enables precise control of carrier lifetime across the 10–100 ps range, while the device demonstrates a high-power capacity of 55 MW. The OEMS delivers a broadband photoelectric response across the P–L band, with peak-to-peak output power exceeding 1 MW over the 0.25–1.3 GHz frequency range and a relative bandwidth of 135%. This represents the highest reported performance to date in terms of combined output power and bandwidth. Additionally, it exhibits low timing jitter and achieves a power-combining efficiency of 98.62% in a 2×2 array configuration. These results highlight the system's strong potential for further development across the frequency, energy, and spatial domains.

GHz burst-mode lasers can offer critical support for many frontier applications. Unfortunately, at present, the generation of all-fiber GHz burst-mode lasers is extremely dependent on external modulation, thus requiring multistage fiber pre-amplifiers to compensate for great power attenuation. Here we demonstrate a simple and efficient method, which actively establishes the combined operation of controllable Q-switching and GHz harmonic mode-locking by performing burst-rectangular intensity modulation in all-fiber polarization-maintaining ring cavity, to directly generate all-fiber GHz burst-mode lasers with flexible temporal tunability. Each burst envelope can contain thousands of sub-pulses with about 17-ps width and 2.35169-GHz repetition rate. More than 20-mW average output power can be achieved with only 400-mW pump power.

We propose a linear polarization and high energy dissipative soliton resonance (DSR) in an all-polarizationmaintaining (all-PM) holmium-doped fiber laser system based on the nonlinear amplifying loop mirror (NALM) for the first time. The fiber laser system includes an all-PM mode-locked seed laser and an all-PM threestage fiber amplifier. In the all-PM seed laser, a segment of polarization-maintaining dispersion compensation fiber (PM-DCF) is utilized to increase intracavity nonlinearity and compensate intracavity dispersion. A selfstarted DSR pulse operating at 2071.9 nm is obtained with a repetition rate of 7.081 MHz and a pulse width of 5.8 ns. The maximum average power is 102.4 mW, corresponding to a pulse energy of 14.5 nJ. To further enhance the pulse energy and output power of the DSR laser system, a three-stage all-PM amplification system is designed. The average pulse power increases to 14.9 W and the pulse energy increases to 2.1 mu J, which represents the highest average power and pulse energy of the all-PM holmium-doped DSR mode-locked fiber laser system. The all-PM holmium-doped DSR laser system demonstrates significant potential for applications in the field of ZGP-OPO systems.

We demonstrate a burst-mode fiber laser system based on an active fiber loop (AFL) to generate high power GHz tunable burst-mode fiber laser. By flexibly adjusting the delay time in the AFL, the intra-burst repetition rate is continuously tunable from 0.89 to 2.25 GHz. The width and shape of the burst-mode envelope can be adjusted by acousto-optic modulator (AOM) and amplifier gain in the AFL, respectively. The repetition rate of the burst-mode fiber laser is 10 MHz. Amplified by a cascaded fiber amplifier, the burst-mode fiber laser achieves the output of 215.4 W at 6 ns of the burst duration. The laser system provides a new scheme for realizing high power GHz tunable burst-mode fiber laser output.

The pumping mechanism based on the cross-phase modulation (XPM) effect can achieve a flat broadband super- continuum (SC) output. In this paper, we demonstrate a novel, to the best of our knowledge, scheme for SC generation from a large mode area (LMA) erbium-ytterbium co-doped fiber (EYDF) amplifier based on this XPM effect by utilizing both the gain and dispersion characteristics of the EYDF, achieving a hundred-watt-level flat broadband SC output. The scheme consists of two pulsed lasers with synchronized trigger signal and a LMA-EYDF amplifier. In order to enhance the XPM effect effectively, the central wavelengths of two pulsed lasers are selected as 1030 nm and 1535 nm according to the calculated group velocity curve of the passive fiber in the EYDF amplifier. The output powers of 1030 nm and 1535 nm pulses are scaled to 58 W and 131 W after the EYDF, where the dual-wavelength is first amplified and the output power is the highest level in the mu m/1.5 mu m dual-wavelength lasers reported so far. After the dual-wavelength lasers undergo the nonlinear accumulation in the EYDF amplifier, the final SC with a spectrum spanning the 770 nm-2055 nm at -10 dB level excluding the residual pump peak is achieved and an output power of 104 W is obtained. This is the widest spectral bandwidth at -10 dB level and the highest output power in the reported SC generation from an EYDF amplifier. This work provides common platform to generate a high-power flat broadband SC independent of fiber design, further promoting the development of LMA fiber-based SC sources. (c) 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

Burst-mode fiber laser has the advantages of rich and adjustable time-domain parameters, and has unique advantages and wide applications in the fields such as material processing, LiDAR, high-speed detection imaging, and microwave photonics. Since the concept of burst-mode fiber laser is proposed, some methods for generating burst-mode fiber laser have emerged, which have promoted the development of burst-mode fiber laser technology. In this paper, the concept of burst-mode fiber laser is first introduced. Second, starts from the method principle of burst-mode fiber laser generation, the generation methods of 1 mu m band burst-mode fiber laser, such as combination of high frequency pulse and active modulation, direct generation, and pulse stacking are introduced, and the advantages, disadvantages, and research status of different methods are emphasize summarized. Then, the typical applications of burst-mode fiber laser are introduced. Finally, the future development trend of burst-mode fiber laser technology is comprehensive analyzed.

Pulsed fiber amplifiers are essential components of high-power pulsed fiber laser systems. To the best of our knowledge, we first propose a type of positive-feedback pulsed fiber amplifier to efficiently amplify weak laser pulses. Positive-feedback mechanism is actively established by the backward time-shifted superposition of seed pulses and feedback pulses. Since the greatly enhanced net input pulses can consume more excited particles to promote excited radiation and suppress spontaneous radiation, our positive-feedback pulsed fiber amplifier achieves a unique near-exponential growth in power curve, higher single-stage gain (17.4 dB, increase of 5.1 dB), and higher pump-to-signal conversion efficiency (19.1 %, increase of 14.6 %) than conventional pulsed fiber amplifiers.

Nanosecond pulsed lasers with flexible temporal designs have presented encouragingly excellent characteristics in particular applications. Unfortunately, even the currently optimal temporal shaping schemes based on iterative correction of optimization algorithms still suffer from extremely low shaping efficiency in nanosecond pulsed fiber master oscillator power amplifier (MOPA) systems. Users are forced to make trade-offs between iteration cost and shaping precision. Through theoretical analysis and experimental verification, we reveal that pulse misjudgment caused by backward pulse energy transfer and poor performance of optimization algorithms are key factors limiting shaping efficiency, and we propose an ultra-efficient temporal shaping scheme based on innovative pulse fitting method and adaptive ratio algorithm. In a nanosecond pulsed fiber MOPA system with over 40-dB gain, we have achieved high-precision arbitrary temporal designs (close to systematic measurement error (similar to 0.5%)) with very few iterations (similar to 10), which is a remarkable progress in terms of shaping efficiency and shaping precision.

In this letter, high power all-fiber short wavelength infrared supercontinuum (SWIR SC) is demonstrated, which is realized in the amplification process of 2 mu m noise-like pulse (NLP). A figure-8 configuration, based on nonlinear amplifying loop mirror (NALM), is set to obtain stable NLP seeds with repetition frequency of 6.31 MHz, pulse widths of 5.21 ns and maximum output power of 162.1 mW. Dual-stage Tm-doped fiber amplifiers (TDFAs) are introduced in the system to achieve efficient power amplification and spectrum broadening. The influences of pre-amplifier power on main output SC characteristics have also been studied, and results demonstrate that high pre-amplifier power leads to high SC output power and broad spectra with power slope efficiency decreasing. A maximum output power of 150 W is obtained with 34.34 % slope efficiency at last, which is the highest SWIR SC power amplified by NLP, to the best of our knowledge. The corresponding SC spectrum with 20 dB spectral bandwidth of 437 nm spans from similar to 1966 nm to similar to 2403 nm. Our research demonstrates that NLP-based SWIR SC has advantages of relatively simple structure and high output power.

Phosphorus-doped fiber has great advantages in supercontinuum (SC) generation because it can narrow the gap between Raman-related peaks and valleys owing to its special Raman gain. In this paper, a random fiber laser (RFL) structure and a main oscillator power amplifier (MOPA) structure are used to pump a self-made phosphorus-doped fiber. The results show that the output spectrum of the latter structure is more favorable in spectral flatness improvement. The 15 dB bandwidth covers from 690 nm to 2320 nm and the output power is 15.1 W. In the range of 1076 -2010 nm, the spectral intensity fluctuates within 3 dB. To the best of our knowledge, the spectral range and flatness are the best among SC generation based on phosphorus-doped fiber methods, which provide a solution for improving the spectral characteristics of the SC