Beam quality, serving as a crucial parameter for assessing laser divergence angle and mode purity, plays a significant role in the control and application of laser. The diamond Raman laser (DRL) combines the beam cleanup effect of stimulated Raman scattering with the excellent optical and thermal properties of the diamond crystal, demonstrating significant advantages in the generation of high-power lasers with high beam quality. In cascaded Raman conversion, the matching effectiveness among multiple modes within the resonator directly impacts the output beam quality and the cascaded conversion efficiency. In this work, a cascaded diamond Raman oscillator was pumped by a 1 & micro;m pump source with low beam quality. The beam quality and conversion efficiency of the cascaded Raman laser were investigated under different mode matching conditions. In the experiment, within a large cavity length adjustment range of 13 mm, the mode matching factor between the pump and the first Raman laser varied by nearly 0.5. Despite this, a 1.5 & micro;m second-order DRL output was achieved, with beam quality improved by a factor of 4.5 compared to the pump. The experimental results demonstrate that the DRL possesses a large mode matching acceptance range and high flexibility in resonator design for improving laser beam quality, further verifying the advantages of DRLs in achieving high-power, high beam-quality laser output with broad wavelength extensibility.

ditelluride (MoTe2), a novel transition metal chalcogenide, exhibits considerable potential for applications in optoelectronic devices. In this article, 1T' and 2H phases of MoTe2 were fabricated into saturable absorbers utilizing the liquid-phase exfoliation technique. The nonlinear saturable absorption characteristics of the 1T' &2H MoTe2 saturable absorbers were evaluated through the open-aperture Z-scan method. Furthermore, passively Q-switched Nd:YAG lasers were developed based on the 1T' &2H MoTe2 saturable absorbers. The results indicate that the 1T' phase of MoTe2 demonstrates superior performance compared to the 2H phase in terms of producing lasers with narrow pulse widths and high repetition rates.

We report a periodically tunable continuous-wave intracavity diamond Raman laser employing a rotating quartz birefringent filter (BRF). Experimental results reveal a counter-intuitive phenomenon where the insertion of a lossy BRF leads to higher Stokes output power compared to the free-running regime. This power enhancement is primarily attributed to the significant spectral narrowing of the fundamental field, which increases the effective Raman gain and overcompensates for the additional insertion losses. By utilizing BRFs with thicknesses of 0.5 and 1 mm, the system achieved stable tuning ranges of approximately 0.24 and 0.3 nm, respectively, with maximum Stokes output powers of 1.24 and 1.05 W. It should be noted that although the absolute wavelength span observed at extreme BRF rotation angles can extend to 2.06 and 1.77 nm, respectively, this is primarily due to intermittent outliers. Both the output wavelength and power exhibit a strict 180° periodicity relative to the BRF rotation angle.

Hyperspectral images (HSIs) provide rich spectral information across hundreds of contiguous bands, enabling fine-grained classification of ground objects. While traditional pixel-wise classification approaches rely mainly on spectral signatures, they often neglect spatial contextual relationships, limiting their discriminative capacity in complex scenes. Recent spectral-spatial classification methods attempt to incorporate spatial information, the majority of them treat spectral and spatial features sequentially, typically performing spectral analysis first, followed by post hoc spatial filtering, thus failing to achieve true spectral −spatial joint modeling. To address this limitation, this paper proposes a novel spectral-spatial classification framework, named superpixel-level spectral similarity metric (SLSSM), which moves beyond pixel-wise modeling by utilizing superpixels as the fundamental classification units, enabling intrinsic integration of spectral and spatial information. Specifically, the proposed method begins with domain transformation recursive filtering (DTRF) and maximum noise fraction (MNF) transformation to preserve edge structures and improve spectral discriminability, while entropy rate superpixel segmentation (ERS) ensures spatially consistent region formation. Classification is then performed by computing spectral similarity between representative pixels within each superpixel and labeled samples, addressing intra-class variability. The class with the highest similarity score is then assigned to all pixels within the corresponding superpixel. Experimental results on three publicly available HSI datasets demonstrate that SLSSM outperforms several state-of-the-art methods including both classical approaches and representative deep learning models. Notably, the proposed method exhibits strong robustness under limited training data, highlighting its practical applicability in real-world remote sensing scenarios where labeled samples are scarce. The source code will be publicly released upon acceptance at https://yuleiwang1.github.io/.

Stimulated Brillouin Scattering (SBS) is one of the important methods for obtaining high-energy pulsed lasers. Its pulse compression characteristics enable the generation of high-peak-power, narrow-pulse-width lasers while maintaining good beam quality, making it promising for applications in fields such as ranging and medical treatment. Based on the stimulated Brillouin scattering (SBS) pulse compression effect, this paper theoretically calculates and simulates the SBS pulse compression performance under different pump pulse widths using liquid FC-770 as the SBS medium. Guided by these calculations, experiments were conducted using a laser with adjustable pulse width as the pump source to compare the influence of different pump pulse widths on pulse compression.This study obtained the variation patterns of output pulse width and energy conversion efficiency with pump energy under different pump pulse widths. This research provides valuable guidance for understanding the pulse compression behavior of SBS and the design of related structures.

Stimulated Brillouin scattering (SBS) enables multi-frequency, high coherent laser emission due to its narrow gain bandwidth and cascaded phase matching. Using a free-space Brillouin oscillator, we systematically study its phase-matching conditions. Experimentally, intracavity Raman scattering is excited by a single-frequency laser to generate SBS. Precise control over the resonance condition between cavity modes and the Brillouin frequency shift allows accurate order control of the cascaded Brillouin laser, demonstrating continuous tuning from the 1st to 5th single-frequency order at 1.2 mu m. Furthermore, by extending the Raman conversion to the 1.5 mu m region, we realize spectral expansion of the multi-frequency, highly coherent laser source.

An 819.710-nm Ti:sapphire laser delivering high pulse energy, sub-pm linewidth, and superior beam quality is reported in this study. Under a 532-nm pump with 826-mJ pulse energy, 100-mu s pulse duration (PD), and 5-Hz repetition rate, the developed laser achieved the highest output pulse energy of 133.5 mJ with a PD of 98 mu s and an optical-to-optical conversion efficiency of 16.1 %. We believe this represents the record 819.710-nm Ti:sapphire laser pulse energy with a PD on the hundred-microsecond level. Its narrow linewidth of 0.8 pm. was realized by incorporating an etalon and a birefringent filter in the cavity. The laser's beam quality factor (M-2) measured 1.315. This laser, in combination with a 589-nm source, could generate polychromatic laser guide stars in the mesospheric sodium layer for tip-tilt correction, thereby facilitating near-diffraction-limited imagery on large ground-based telescopes.

While high-strength steels are crucial for critical structural applications, they frequently suffer from the synergistic threats of wear, corrosion, and fatigue. Although laser shock peening (LSP) is widely utilized for its ability to generate deep compressive residual stresses, achieving precise localized treatment on complex micro-scale structures remains a fundamental challenge for conventional LSP. To overcome this limitation, this study developed a micro-region LSP (mrLSP) strategy to enable precise surface strengthening of CH1900A martensitic steel. To mitigate the detrimental influence of rarefaction waves, a laser system characterized by high beam quality and a small spot size was employed in conjunction with an equilateral triangular scanning strategy. When the induced peak pressure was restricted to approximately 2 to 2.5 times the Hugoniot elastic limit (σHEL) under the optimal peak power density, the treated CH1900A martensitic steel exhibited a 43% reduction in corrosion current density, a 69% decrease in wear rate, and a 19% increase in yield strength. The microstructural evolution was elucidated, demonstrating that the strengthening mechanism stems from the combined contributions of a gradient compressive residual stress field, high density dislocation, and grain refinement. Furthermore, mechanistic analysis revealed that pitting corrosion initiated at carbide precipitates with subsequent crack propagation along grain boundaries, whereas the wear behavior was dominated by abrasive and oxidative mechanisms. The quantitative contributions of various mechanisms to the overall properties were evaluated, revealing further grain refinement as the primary pathway for performance enhancement. This study establishes a robust theoretical and technical framework for the precise surface treatment of complex structural components.

Salient object detection (SOD) in optical remote sensing images (ORSIs) often encounters challenges, including complex target structures, strong background interference and the difficulty of accurately capturing edge infor mation. To address these issues, a novel salient object detection network named EAFBSNet is proposed, which integrates edge-awareness and foreground-background separation mechanisms aimed at improving detection ac curacy and preserving the edge details of salient targets. EAFBSNet consists of three core modules: (1) Graph Edge Perception Module (GEPM) employs a self-attention mechanism to model the spatial relationships between targets and the background, facilitating precise extraction of object edge information while adaptively filter ing out irrelevant background noise; (2) Multi-scale Context Fusion Module (MCFM) performs deep integration of encoder features alongside edge features while leveraging multi-scale contextual information to enhance the model's adaptability to salient objects at varying scales; (3) Foreground-Background Separation Cascade Decoder (FBSCD) models feature streams associated with foregrounds and backgrounds through multi-level feature inter action combined with a guided attention enhancement mechanism. Experimental results on multiple publicly available remote sensing datasets demonstrate that EAFBSNet achieves significant improvements in performance within the ORSI-SOD task. Notably, it excels in detail preservation under challenging scenarios, such as complex background interference and blurred object boundaries.

To overcome the insufficient long-term stability of conventional Raman lasers, we demonstrate a single-frequency diamond Raman laser enabled by a pump-wavelength locking strategy. A three-mirror V-shaped cavity pumped by a 1064 nm fiber laser (6 kHz linewidth) provides single-longitudinal-mode (SLM) output at 1240 nm using Pound-Drever-Hall (PDH) stabilization. We further find that eliminating active temperature control of the diamond crystal suppresses rapid thermal perturbations and improves short-term stability. To compensate thermally induced slow cavity-length drifts, we implement a dual-loop feedback architecture that employs a fast PID loop acting on the pump wavelength and a slow PID loop driving a cavity piezoelectric transducer (PZT). Specifically, the fast loop tunes the pump wavelength via laser-current modulation, while the slow loop stabilizes the cavity length by regulating the PZT voltage. With 22 W pump power, the system produces 2.5 W SLM output with a linewidth of ∼2.9 kHz. The locked Raman laser exhibits an output power instability below 1.59% and a wavelength drift below 87 MHz, demonstrating markedly improved long-term operational stability. Unlike mainstream cavity-length locking techniques, our approach exploits the PDH error signal to directly lock the pump wavelength, providing a high-performance and wavelength-scalable route to highly stable single-frequency laser sources.

Single-frequency continuous-wave lasers are critically important for advanced applications in quantum information science, high-precision metrology, and lidar systems. These applications demand laser sources that combine a narrow linewidth, low amplitude and frequency noise, and high temporal coherence. A significant challenge in the field is scaling the output power of such lasers while simultaneously preserving their superior spectral purity and high stability. Conventional techniques for achieving single-frequency operation often face limitations in power scaling due to thermal effects and nonlinearities. This research demonstrates a high-power, single-frequency Nd:YVO4 laser system utilizing the seed injection-locking technique. A stable, narrow-linewidth fiber laser operating at 1 064 nm serves as the master oscillator. The slave laser is configured as an "8"-shaped ring resonator, which is pumped by an 888 nm diode laser. A composite Nd:YVO4 crystal is used as the gain medium to mitigate thermal lensing effects. Active frequency stabilization is implemented using the Pound-Drever-Hall (PDH) method. An error signal, derived from the cavity transmission, feeds back to a piezoelectric transducer to control the slave cavity length, thus locking it to the seed laser frequency. Under optimal injection-locking conditions and at a pump power of 38.12 W, the laser delivers a maximum output power of 13.5 W in a single longitudinal mode. The linewidth of the amplified output is measured to be 7.0 kHz. This represents only a minor broadening compared to the 5.6 kHz linewidth of the original seed laser. The system exhibits excellent power stability, with a root-mean-square power instability of less than 0.18% over a continuous 60-minute period. Furthermore, the frequency stability is significantly enhanced through injection locking. The long-term wavelength drift is reduced to 132.4 MHz, a substantial improvement over the 300 MHz drift observed for the free-running seed laser. A detailed frequency noise characterization reveals effective suppression of noise at low Fourier frequencies (1 similar to 100 Hz) in the locked state compared to the free-running slave laser. A slight increase in noise is observed at higher frequency offsets, which is attributed to residual mechanical vibrations from the locking actuator. These results confirm that the seed injection-locking technique successfully amplifies the optical power while maintaining the spectral characteristics of the seed. Crucially, this high stability is achieved without the need for active frequency stabilization of the seed laser itself. This work contributes by achieving a compelling combination of high power (13.5 W), narrow linewidth (7.0 kHz), and high stability at the important 1 064 nm wavelength. A key finding is that this high stability is accomplished without requiring active stabilization of the seed laser itself. The results robustly demonstrate that the seed injection-locking technique is a highly effective method for amplifying optical power while simultaneously preserving and even enhancing the frequency stability and spectral characteristics of the original seed source. In conclusion, this research successfully realizes a high-power, narrow-linewidth, low-noise single-frequency Nd:YVO4 laser. The system exhibits outstanding power and frequency stability, making it suitable for demanding applications. The approach provides a viable and practical pathway for developing high-performance single-frequency lasers. Future work will focus on refining the feedback control system to achieve even lower frequency noise. Additionally, the integration of intracavity nonlinear frequency conversion techniques, such as second harmonic generation, could be implemented to produce high-power, single-frequency radiation at other strategically important wavelengths, further expanding the utility of this laser architecture.

Narrow-linewidth solid-state laser sources play an indispensable role in fields such as precision spectroscopy, quantum information processing, high-resolution sensing, and advanced manufacturing. Traditional narrow-linewidth laser technologies are often limited by thermal effects in gain medium, restricted wavelength tuning ranges, and system complexity. In recent years, solid-state Raman lasers based on the gain mechanism of Stimulated Raman Scattering, particularly those using single-crystal diamond as the gain medium, have emerged as highly promising solutions for achieving high-power, high-beam-quality, narrow-linewidth output, garnering significant international research attention. This article systematically reviews and discusses the latest research progress in narrow-linewidth solid-state diamond Raman lasers. It begins by examining the underlying physical mechanisms, highlighting the intrinsic properties of the SRS process such as the absence of spatial hole burning and its spectral cleansing effect, which lay the physical foundation for obtaining narrow-linewidth output directly. Among numerous Raman gain medium, diamond stands out due to its nearly extreme physical properties: its extremely high thermal conductivity (over 2 000 W.m(-1).K-1) enables effective management of heat generated under high-power pumping, its broad transmission range from 225 nm to the mid-infrared enables wavelength extension, its large Raman shift of 1 332.3 cm(-1) facilitates generation of special bands like eye-safe wavelengths, and its high Raman gain coefficient (similar to 10 cm/GW) ensures efficient conversion. These characteristics make diamond an almost ideal gain medium for achieving high-power, narrow-linewidth lasers, especially in scenarios with stringent thermal management requirements. This article focuses on discussing five main technical solutions for achieving narrow linewidth output, and compares their respective advantages and challenges. Firstly, by utilizing the gain characteristic of SRS without spatial hole burning, and through ingenious design of the resonator structure (such as V-shaped cavity), parasitic stimulated Brillouin scattering is suppressed, thereby achieving single longitudinal mode operation without the need to introduce additional frequency-selecting components. This method is simple in structure and easy to implement, and has successfully achieved continuous wave output with a linewidth as low as 105 kHz, as well as pulsed single-frequency output within the tens of megahertz range. Secondly, combining SRS with intracavity frequency doubling/sum-frequency generation, leveraging the inherent harmonic self-suppression effect and strong mode selectivity of nonlinear frequency conversion processes. This scheme not only extends the output wavelength into the visible spectrum but also further narrows and stabilizes the linewidth. It has yielded high-performance single-frequency output with linewidths below 10 MHz and powers of tens of watts at critical wavelengths such as 589 nm for sodium guide star lasers and 620 nm for yellow-red light, demonstrating excellent overall performance. Thirdly, employing frequency-selective elements like F-P etalons, inserted into either the fundamental or Raman cavity to finely filter the oscillating spectrum. This method offers direct and flexible linewidth control and is a common means of obtaining stable, narrow-linewidth output, though it typically introduces additional insertion loss and is sensitive to environmental temperature drift. Fourthly, by combining the advantages of the F-P etalon and the birefringent filter, the F-P etalon can perform fine frequency selection, while the birefringent filter has high stability, to achieve output with narrow linewidth, high stability, and certain tunability. Fifthly, the introduction of seed injection technology enables extremely narrow linewidth and precise frequency locking by injecting external narrow-linewidth seed laser, but the system complexity and cost increase significantly. This article elaborates on the principles, key breakthroughs, and achieved performance indicators of each technical solution through rich experimental cases and data. Despite the significant performance advantages of diamond, its high material and processing costs remain a major constraint on its widespread application. Traditional Raman crystals such as KGW, BaWO4, and YVO4, with their mature manufacturing processes and lower costs, maintain their competitiveness in specific low and medium power applications. Future research will focus on multiple dimensions: continuing to explore new mechanisms and structures to further compress linewidths to the kHz level and beyond, meeting the extreme demands of applications like quantum precision measurement; overcoming challenges in thermal management and nonlinear effect suppression at high powers to enable continuous power scaling; developing wider-range, faster wavelength tuning technologies to cover broader application spectra; and promoting system development towards modularization, integration, and intelligence. With the continuous advancement and potential cost reduction of Chemical Vapor Deposition techniques for producing high-quality single-crystal diamond, diamond solid-state Raman lasers are poised to play an increasingly important role in high-end scientific research, defense technology, and industrial manufacturing, propelling related technologies to new heights.

We present a continuous-wave intracavity Raman laser employing diamond crystals with different birefringence strengths and fast-axis orientations as the Raman medium. The results show that the birefringence properties of the diamond significantly influence the output power, beam quality, and polarization characteristics of the laser. A diamond crystal with lower birefringence enabled nearly diffraction-limited beam quality with a beam quality factor of M2 = 1.04. When the fast axis was oriented closer to the (1 1 1) crystallographic direction and the birefringence was weaker, the Raman laser achieved superior output performance, with a maximum output power of 1.5 W. Furthermore, by introducing a half-wave plate inside the cavity, the Stokes polarization direction was maintained within 90 degrees-100 degrees, and the output power exhibited a symmetric distribution with respect to the waveplate angle.

We propose a multifunctional terahertz (THz) metasurface based on a multilayer vanadium dioxide (VO 2 ) hybrid structure that achieves high-contrast switching between a perfect absorber and an off-axis vortex beam generator. In the metallic state, the metasurface operates as a high-performance absorber, exhibiting a near-perfect absorption exceeding 99% at 2.3 THz, with a fractional bandwidth of 43%. Conversely, in the insulating state, the structure acts as a precise geometric phase modulator; it successfully generates well-defined deflected vortex beams with customizable topological charges across multiple frequency channels (1.25, 2.1, and 3 THz). This integrated THz platform promises advancements in advanced communication, dynamic beam steering, and electromagnetic camouflage.

Stress in diamond crystals is a critical factor affecting Raman gain and the polarization state of the output Stokes. This study systematically investigates the multi-field coupling among residual-stress-induced birefringence in diamond, initial pump ellipticity, and stimulated Brillouin scattering (SBS). By combining theoretical simulations, division-of-focal-plane polarization imaging, and Raman laser experiments, we elucidate the mechanisms responsible for the stepwise evolution of the Stokes polarization direction. In high-stress regions, birefringence-induced phase distortion dominates the polarization dynamics, leading to abrupt polarization switching. In low-stress regions, SBS acts as a parasitic loss channel that forces polarization-mode transitions and limits power scaling. The results further confirm that even slight pump polarization perturbations can degrade the Raman output polarization state, reduce the effective gain, and increase the laser threshold. These theoretical and experimental findings provide practical guidance for overcoming performance bottlenecks in diamond Raman lasers, screening high-quality crystals, and developing efficient coherent light sources with precisely controllable polarization states.

Infrared small target detection is focused on accurately identifying tiny targets with low signal-to-noise ratio against complex backgrounds, representing a critical challenge in the field of infrared image processing. Existing approaches frequently fail to retain small target information during global semantic extraction and struggle with preserving detailed features and achieving effective feature fusion. To address these limitations, this article proposes a morphology-edge enhanced triple-cascaded network (MEETNet) for infrared small target detection. The network employs a triple-cascaded architecture that maintains high resolution and enhances information interaction between different stages, facilitating effective multilevel feature fusion while safeguarding deep small-target characteristics. MEETNet integrates an edge-detail enhanced module (EDEM) and a detail-aware multi-scale fusion module (DMSFM). These modules introduce edge-detail enhanced features that amalgamate contrast and edge information, thereby amplifying target saliency and improving edge representation. Specifically, EDEM augments target contrast and edge structures by integrating edge-detail-enhanced features with shallow details. This integration improves the discriminability capacity of shallow features for detecting small targets. Moreover, DMSFM implements a multireceptive field mechanism to merge target details with deep semantic insights, enabling the capture of more distinctive global contextual features. Experimental evaluations conducted using two public datasets—NUAA-SIRST and NUDT-SIRST—demonstrate that the proposed MEETNet surpasses existing state-of-the-art methods for infrared small target detection in terms of detection accuracy.

We propose and experimentally demonstrate a high-efficiency cascaded Raman structured-light laser based on a Ba(NO3)2 crystal. By combining a non-collinear V-shaped resonator with large-mode-area pumping and mode-size matching to high-order Stokes eigenmodes, the spatial overlap between the pump and target Stokes fields is improved, enabling enhanced Raman gain extraction and efficient cascaded conversion of high-order structured modes. High-quality one-dimensional Hermite-Gaussian (HG) modes up to the 20th order and two-dimensional HG modes are generated, together with direct intracavity generation of a first-order Laguerre-Gaussian (LG) mode and extracavity conversion to higher-order LG modes. At the second-Stokes wavelength of 1369 nm, the HG modes achieve a maximum pulse energy of 0.55 mJ with a conversion efficiency above 35%, while the directly generated LG mode reaches 0.64 mJ with a maximum conversion efficiency of 42%. The structured Raman output also preserves pulse compression, with durations 1-2 ns shorter than those of the pump. This work provides an effective route for high-efficiency wavelength extension of high-energy structured light.

High-precision, non-contact surface inspection is essential for semiconductor manufacturing and micro-electromechanical systems (MEMS). However, the measurement accuracy of white-light interferometry (WLI) is often degraded by the batwing effect around step edges, leading to systematic deviations in practical metrology. This paper proposes a novel edge-guided CEEMDAN-wavelet fusion denoising strategy that specifically targets batwing-induced distortions in coherent interference signals. By integrating Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) and adaptive wavelet thresholding under edge guidance, the method suppresses the batwing effect and random noise while preserving the integrity of steep edge structures that are critical for dimensional control. Experiments conducted on VLSI standard step height samples, gratings, and silicon wafers demonstrate nanometric measurement accuracy under realistic conditions: the measured step height reaches 1.808 +/- 0.0106 mu m (relative error 0.444 %), and the absolute error in grating height is only 0.007 mu m (relative error 0.4 %). For silicon wafers, the reconstructed surface roughness parameters obtained using the proposed method are significantly closer to those measured by a commercial profiler than those derived from conventional median and mean filtering, indicating improved reliability in process monitoring and surface quality assessment. These results show that the proposed WLI signal-processing scheme can substantially enhance the accuracy and robustness of topography reconstruction, highlighting its strong potential for deployment in both in-line and off-line high-precision surface inspection in semiconductor and MEMS manufacturing.

The single-cavity dual-repetition-frequency self-mode-locked Tm,Ho:YLF laser is first demonstrated. Combining the natural birefringence characteristic and the soft-hole Kerr lens effect of gain medium itself, the orthogonally polarized dual-repetition-frequency self-mode-locked Tm,Ho:YLF laser with a single cavity was successfully realized. For the π-polarized and σ-polarized pulse lasers, the balanced average output powers of 282 mW and 298 mW were attained at an absorbed pump power of 2.16 W, the pulse repetition frequencies were 1.7148 GHz and 1.7173 GHz, and the output wavelengths were 2065.3 nm and 2063.8 nm. To the best of our knowledge, this is the first single-cavity dual-repetition-frequency self-mode-locked solid-state laser in the 2 µm waveband.

Stimulated Brillouin scattering (SBS) is an effective method for obtaining high-brightness and high-beam-quality lasers. The research work on SBS has made great progress, but it is basically limited to the independent study of steady state and transient state, and there is a lack of ways to accurately characterize and predict the evolution law of SBS output characteristics in the complete time range (from steady state to transient continuous change process). We use the concept of redundant gain Gf to quantitatively characterize the output characteristics of the steady-transient SBS pulse compression process, and establish bidirectional mapping relationships of pump intensity and energy reflectivity, pump pulse width, and compression ratio. The accurate prediction of the output characteristics of SBS under arbitrary conditions during the steady-transient continuous change process is realized, and it is verified experimentally. In addition, the evolution law of energy distribution in the time domain in steady-transient SBS pulse compression is investigated by using the SBS frequency detuning effect. Essential differences in the compression mechanism and physical processes of steady-transient SBS are elucidated. The energy reflectivity of the whole system is nearly 40%, and the effective compression ratio is ∼ 96.