Submit to Special Issue Submit Abstract to Special Issue Review for Photonics Propose a Special Issue

Journal Menu

Journal Browser

Advanced Lasers and Their Applications, 3rd Edition

Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Related Special Issue
Published Papers

A special issue of Photonics (ISSN 2304-6732). This special issue belongs to the section "Lasers, Light Sources and Sensors".

Deadline for manuscript submissions: 15 December 2026 | Viewed by 5011

Share This Special Issue

Special Issue Editors

Dr. Xinyao Li

E-Mail
Guest Editor

Laboratory of All-Solid-State Light Sources, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
Interests: fiber laser; mode-locking; Q-switching; nonlinear optics

Dr. Chao-Jian He

E-Mail
Guest Editor

Laboratory of All-Solid-State Light Sources, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
Interests: fiber laser; mode-locking; Q-switching
Special Issues, Collections and Topics in MDPI journals

Dr. Song Yang

E-Mail Website
Guest Editor

Laboratory of All-Solid-State Light Sources, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
Interests: nonlinear optics; nano/micro fabrication; laser imaging; optical sensor
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Recent advancements in laser technology have revolutionized various scientific and industrial fields, enabling unprecedented precision, power, and versatility. This Special Issue focuses on cutting-edge developments in laser systems, including ultrafast lasers, high-power lasers, fiber lasers, and novel laser sources, as well as their emerging applications in areas such as biomedical engineering, optical communications, materials processing, quantum technologies, and defense systems. We invite original research articles and reviews that explore innovative designs, novel materials, and transformative applications of advanced lasers.

The goal of this Special Issue is to provide a platform for researchers to share breakthroughs in laser physics, engineering, and interdisciplinary applications. Topics of interest include (but are not limited to):

laser sources;
nonlinear optics;
laser spectroscopy;
laser-based manufacturing;
medical and biophotonic applications;
laser-driven quantum systems.

By bringing together leading experts, we aim to highlight the latest trends, challenges, and future directions in laser technology and its expanding role in modern science and industry.

Dr. Xinyao Li
Dr. Chao-Jian He
Dr. Song Yang
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Photonics is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

fiber laser
all-solid-state laser
semiconductor laser
micro/nano structure fabrication
optical sensor

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

Related Special Issue

Advanced Lasers and Their Applications, 2nd Edition in Photonics (21 articles)

Published Papers (10 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

16 pages, 3332 KB

Open AccessArticle

Temperature-Controlled CO₂ Laser Polishing of Fused Silica Microlens Arrays

by He Li, Enbing Qi, Jun Liu, Shuo Jin, Wenqi Ma and Junjie Zhang

Photonics 2026, 13(5), 454; https://doi.org/10.3390/photonics13050454 - 5 May 2026

Abstract

While fused silica microlens arrays (MLAs) act as crucial components in the fields of infrared optics and laser systems, direct laser writing has been proposed for the fabrication of MLAs. However, the layer-by-layer slicing strategy generally leads to stepped surface textures formed on the microlens surface, resulting in high surface roughness and limited transmittance. This work proposes a temperature-controlled CO₂ laser polishing method for the fabrication and subsequent smoothing of fused silica microlens arrays. Specifically, an infrared temperature measurement system is integrated into a CO₂ laser direct writing platform. Correspondingly, a proportional-integral-derivative algorithm is used to adjust the laser power in real time based on the temperature deviation at the processing spot, thus maintaining the polishing zone in a molten rather than vaporizing state. Furthermore, a finite element model of laser polishing of fused silica coupled with laser heating and fluid flow is developed, which is used to analyze the spatiotemporal evolution of the temperature field, as well as its correlation with the response of the processed surface. Experimental results show that temperature-controlled laser polishing reduces the surface roughness of the fabricated MLAs by 86.8%, while the transmittance in the visible band remains above 90%. This work provides a feasible closed-loop polishing method and a mechanistic analysis model for the laser polishing of fused silica MLAs. Full article

(This article belongs to the Special Issue Advanced Lasers and Their Applications, 3rd Edition)

► Show Figures

Figure 1

13 pages, 3338 KB

Open AccessArticle

Laser Turning with Advanced Process Monitoring by Optical Microphone

by Julian Zettl, Christian Lutz and Ralf Hellmann

Photonics 2026, 13(5), 448; https://doi.org/10.3390/photonics13050448 - 1 May 2026

Viewed by 197

Abstract

We report on a novel approach for the monitoring of tangential laser turning with ultrashort laser pulses. By using an ultra-sonic sensor consisting of a membrane-free optical microphone, the current state of the ablation process can be analyzed, potentially enabling a real-time automated regulation. With its high sensitivity, bandwidth, and sampling rate, it is an ideal tool for process monitoring. The material ablation caused by focused femtosecond laser pulses produces distinct sound waves, which can be detected by the optical microphone. The diameter reduction of a rotating cylindrical workpiece during the laser turning process with ultrashort laser pulses results in a variation in the acoustic emissions. From this, properties like the state of the machining progress can be inferred. Full article

(This article belongs to the Special Issue Advanced Lasers and Their Applications, 3rd Edition)

► Show Figures

Figure 1

17 pages, 4918 KB

Open AccessArticle

Robust Process Parameter Optimization for Undamaged Laser Cutting of Q235B Double-Layer Narrow-Gap Steel Plates Using Random Forests

by Junzhi Sun, Tianci Zhang, Chenglin Wang, Haosheng Liu, Chongxin Tian, Zhiyan Zhang, Shaoxia Li and Ling Zhang

Photonics 2026, 13(4), 315; https://doi.org/10.3390/photonics13040315 - 25 Mar 2026

Viewed by 424

Abstract

To address the challenge of cutting double-layer narrow-gap steel plates without damaging the lower plate, we conducted systematic laser-cutting experiments and achieved full penetration of the upper plate without damaging the lower plate. Three cutting outcomes were defined: Unpenetrated, Undamaged, and Damaged. A random forest (RF) classifier was developed to predict the cutting outcomes, achieving 100% precision for the Undamaged class on a test split and an overall accuracy of 96.9%. The feature importance analysis indicates that laser power has an importance score of 0.230, confirming it as the most influential feature in the model. The mean regional variation in undamaged probability was computed to guide the progressive expansion of the search window for parameter optimization. The procedure was conducted with the objective of identifying the most robust parameter combinations over the global parameter space at different cutting speeds. The proposed method provides quantitative decision support for robust undamaged cutting under narrow-gap conditions. Full article

(This article belongs to the Special Issue Advanced Lasers and Their Applications, 3rd Edition)

► Show Figures

Figure 1

14 pages, 1363 KB

Open AccessArticle

Comparative Study of PLSR and SVR Using MLP Feature Extraction for Quantitative Analysis of Steel Alloy Elements by Laser-Induced Breakdown Spectroscopy

by Weifeng Chen and Yu Ding

Photonics 2026, 13(2), 186; https://doi.org/10.3390/photonics13020186 - 13 Feb 2026

Cited by 1 | Viewed by 385

Abstract

With the rapid development of the steel industry, the accurate detection of alloy element contents is of great significance for the evaluation of material properties and quality control. This study aims to establish a rapid, stable, and highly accurate quantitative detection method based on handheld LIBS to achieve effective analysis of key elements such as Fe, Cr, Mn, Ni, and Cu. To meet the demand of the steel industry for rapid, stable, and high-accuracy quantification of key alloy elements such as Cr, Mn, Ni, and Cu, this study was carried out on 20 types of standard steel spectral samples. Support Vector Regression (SVR) and Partial Least Squares Regression (PLSR) models were constructed, respectively. The SVR penalty factor C (0.1–10) and loss parameter ε (0.001–1), as well as the PLSR latent variable number Lv (1–20), were optimized using five-fold cross-validation repeated 100 times. Model performance was evaluated using the coefficient of determination (R²), root-mean-square error (RMSE), and mean relative error (MRE). In the comparison of quantitative performance, excellent predictive ability for major elements such as Fe and Cr was achieved by both models; test-set R² values exceeded 0.92, meeting the detection requirements for high-content alloy elements. For low-content Ni, Cu, and Mn, PLSR gives R² values of 0.92, 0.93, and 0.89, while SVR yields 0.85, 0.49, and 0.36, showing clear limitations, especially for Cu and Mn. After introducing Multilayer Perceptron feature extraction, the R² of Ni, Cu, and Mn increases to 0.99, 0.99, and 0.97 for PLSR and to 0.99, 0.93, and 0.94 for SVR, with RMSE and MRE markedly reduced. In summary, the integration of LIBS with MLP feature extraction and PLSR offers both rapid processing capabilities and high precision, significantly improving the quantification of low-concentration elements, and is well-suited for real-time online monitoring in steel production, facilitating quality control and process optimization. Full article

(This article belongs to the Special Issue Advanced Lasers and Their Applications, 3rd Edition)

► Show Figures

Figure 1

10 pages, 3088 KB

Open AccessArticle

256.5-W Chirped Amplitude-Modulated Fiber Laser for Single-Photon Differential Ranging

by Wenjuan Wu, Shuzhen Zou, Haijuan Yu, Chaojian He and Song Yang

Photonics 2026, 13(2), 150; https://doi.org/10.3390/photonics13020150 - 3 Feb 2026

Viewed by 466

Abstract

High-power chirped amplitude-modulated (CAM) lasers serve as essential sources for the promising high-precision single-photon differential ranging technique. However, the development of high-power CAM lasers is fundamentally constrained by the stimulated Brillouin scattering (SBS) effect and the degradation of the CAM waveform during amplification. In this work, we propose a high-power CAM fiber laser system based on a dual linear frequency modulation (dual-LFM) architecture, wherein LFM signals are applied simultaneously to both the phase modulator and the intensity modulator. The experimental results demonstrate effective suppression of SBS, which enables an approximately eightfold enhancement in average output power—from 32.1 W to 256.5 W—while maintaining well-preserved CAM waveforms and a near-diffraction-limited beam quality (

M^{2}

= 1.073). To the best of our knowledge, this represents the highest output power reported to date for CAM lasers. Significantly, after amplification, the system exhibits a mere ~2% reduction in average modulation depth, attaining a final modulation depth of over 82%, a total harmonic distortion below 7%, and excellent CAM linearity across the 100 MHz to 1 GHz modulation frequency range. Furthermore, the proposed laser system enables single-photon differential ranging with millimeter-level precision over distances exceeding 100 km. This work represents a significant advancement in CAM laser power scaling, with potential applications in advanced precision ranging, quantum technology, and related emerging fields. Full article

(This article belongs to the Special Issue Advanced Lasers and Their Applications, 3rd Edition)

► Show Figures

Figure 1

9 pages, 5546 KB

Open AccessArticle

Dispersion Analysis and Control in a Yb-Doped Fiber Chirped Pulse Amplification System and Second-Harmonic Generation

by Zhengying You, Qian Wang, Yuanyuan Fan, Yifan Zhao, Yan Qi, Boxia Yan, Ning Wen, Zhe Han, Mi Zhou and Yanwei Wang

Photonics 2026, 13(2), 118; https://doi.org/10.3390/photonics13020118 - 27 Jan 2026

Viewed by 510

Abstract

We report a dispersion-controlled Yb-doped fiber chirped pulse amplification (CPA) system incorporating a tunable chirped fiber Bragg grating (CFBG) stretcher and a single-grating transmission compressor for dynamic compensation of power-dependent nonlinear effect. During the pulse amplification, the CFBG introduces adjustable third-order dispersion (TOD). By tuning the initial TOD provided by CFBG from −0.1965 ps³ at 2.37 W to −0.1791 ps³ at 9.65 W, residual TOD is efficiently compensated with the power-dependent nonlinear effect. As a result, by optimizing the dispersion balance at each output power, nearly constant femtosecond pulses with a duration of 250 fs are obtained over the entire power range, confirming effective control of nonlinear and dispersive effects in the amplification. The high-quality 1030 nm pulses enable efficient second-harmonic generation (SHG) in a type-I BBO crystal, producing 3.56 W femtosecond output at around 515 nm with a pulse duration of 190 fs, close to the Fourier transform limit. These results demonstrate a robust approach to generating high-power and temporal coherent ultrafast pulses suitable for precision micromachining and two-photon polymerization. Full article

(This article belongs to the Special Issue Advanced Lasers and Their Applications, 3rd Edition)

► Show Figures

Figure 1

14 pages, 2404 KB

Open AccessArticle

Red-Pitaya-Based Frequency Stabilization of 1560-nm Fiber Laser to 780-nm Rubidium Atomic Transition via Single-Pass Frequency Doubling

by Yirong Wei, Ziwen Wang, Yuewei Wang, Yuhui Yang, Tao Wang, Rui Chang and Junmin Wang

Photonics 2026, 13(1), 57; https://doi.org/10.3390/photonics13010057 - 7 Jan 2026

Viewed by 824

Abstract

The single-step Rydberg excitation of cesium atoms requires a 319 nm ultraviolet laser with a narrow laser linewidth, high frequency stability, and high output power. To meet these requirements, in this work, we construct a high-power, single-frequency UV laser system at this wavelength. In this system, the frequency stabilization of the 1560.492 nm seed laser is critical to the performance of the ultraviolet laser. We employ nonlinear frequency conversion technology, the 1560.492 nm laser is frequency-doubled to 780.246 nm via a single pass through a PPLN crystal, and function integration is realized based on the modular parameter adjustment interface provided by the PyRPL software. Subsequently, the 1560.492 nm laser is stabilized to the

D_{2}

hyperfine transition line of Rb-87 atoms using polarization spectroscopy (PS) and radio-frequency-modulated saturation absorption spectroscopy (RF-SAS). A comparative study of these two techniques shows that RF-SAS achieves superior stabilization performance, with the residual frequency fluctuation of the frequency-doubled laser being 1.07 MHz over 30 min. According to frequency doubling theory, the actual residual frequency fluctuation of the 1560.492 nm fundamental-frequency laser can be calculated as 0.535 MHz. Compared with our earlier scheme that utilized an ultra-low-expansion (ULE) optical cavity as a frequency reference, the present scheme eliminates the long-term drift induced by environmental factors. In contrast to frequency stabilization relying on discrete instruments, this integrated scheme significantly reduces the cost, simplifies the system architecture, saves space, and greatly enhances the flexibility and controllability of the system. It therefore provides a reliable and cost-effective solution to ensure the portability and practicability of high-performance UV laser sources. This high-precision frequency stabilization scheme directly guarantees the performance of the 319 nm UV laser, suppressing its linewidth below 10 kHz. Thus, it fully meets the stringent laser linewidth and frequency stability requirements for the single-step Rydberg excitation of cesium atoms and provides a reliable light source foundation for subsequent precision spectroscopic measurements. Full article

(This article belongs to the Special Issue Advanced Lasers and Their Applications, 3rd Edition)

► Show Figures

Figure 1

10 pages, 1788 KB

Open AccessArticle

Toward Octave-Spanning Mid-Infrared Supercontinuum Laser Generation Using Cascaded Germania-Doped Fiber and Fluorotellurite Fiber

by Xuan Wang, Yahui Zhang, Chuanfei Yao, Linjing Yang, Yunhao Zhu and Pingxue Li

Photonics 2026, 13(1), 50; https://doi.org/10.3390/photonics13010050 - 5 Jan 2026

Viewed by 395

Abstract

Mid-infrared (MIR) supercontinuum (SC) sources are critical for spectroscopy, biomedical imaging, and environmental monitoring. However, conventional generation methods based on free-space experiments using optical parametric amplifiers (OPAs) and difference frequency generation (DFG) lasers suffer from narrow bandwidth and low power distribution in the MIR region. This paper presents a cascaded pumping technique using two soft-glass fibers. A picosecond thulium-doped fiber amplifier (TDFA) pumps a Germania-doped fiber (GDF) to generate an intermediate broadband spectrum, which then pumps a fluorotellurite fiber (TBY) with higher nonlinearity and a wider transmission window. Using this configuration, we achieved an Octave-Spanning SC generation covering 1–4 μm with 7.20 W output power. Notably, 32.8% of total power lies above 3.0 μm, with 11.2% beyond 3.5 μm, demonstrating excellent long-wavelength performance. In addition, we applied numerical simulation methods to investigate SC generation in GDF and TBY by solving the nonlinear Schrödinger equation. The close match between simulated and experimental results facilitates theoretical examination of how SC broadening occurs. This cascaded approach offers a feasible solution in terms of spectral band matching, material compatibility, and system integration potential. Full article

(This article belongs to the Special Issue Advanced Lasers and Their Applications, 3rd Edition)

► Show Figures

Figure 1

10 pages, 1745 KB

Open AccessArticle

Multi-Band FMCW Signal Generator with a Tunable Sweep-Frequency Bandwidth and Inter-Band Interval

by Md Mamun-Ur-Rashid, Qiupin Wang, Xin Tong, Pu Ou, Guangqiong Xia and Zhengmao Wu

Photonics 2026, 13(1), 48; https://doi.org/10.3390/photonics13010048 - 5 Jan 2026

Viewed by 505

Abstract

In this work, we experimentally demonstrate a scheme for generating a multi-band FMCW signal with a tunable sweep bandwidth and inter-band interval. For such a scheme, an original FMCW signal is first acquired by directly current-modulating a master distributed feedback semiconductor laser (DFB-SCL) using a pre-distorted triangular waveform. Then, the original FMCW signal is injected into a slave DFB-SCL, in which a multi-band FMCW signal is generated via the four-wave mixing (FWM) effect. The experiment results show that, under appropriate injection parameters, a tri-band FMCW signal can be obtained, which is composed of a regenerated original FMCW signal (named as main band) and two newly generated FMCW signals originating from idler waves (named as upper band and lower band, respectively). Under the optical injection with negative frequency detuning, the sweep-frequency bandwidth for upper band is the same as that of the original FMCW signal, and the sweep-frequency bandwidth for lower band is twice that of the original FMCW signal. Meanwhile, the interval between the central frequencies of two adjacent bands depends on the frequency detuning between two DFB-SCLs operating at free-running. By adjusting the sweep-frequency bandwidth of the original FMCW signal and the temperature of the slave DFB-SCL, the sweep-frequency bandwidth of each band and the interval between two adjacent bands of the generated FMCW signal can be tuned. For demonstration of a proof of concept, we inspect the case that the original FMCW signal with a sweep-frequency bandwidth varied within 3 GHz~7 GHz and the frequency detuning varied within 44 GHz~59 GHz. The corresponding results demonstrate that each band with the different sweep-frequency bandwidth possesses high linearity of R² > 0.990 under the frequency detuning fixing at 59 GHz. Such a scheme offers a simplified architecture for generating multi-band FMCW signals with a tunable sweep-frequency bandwidth and inter-band interval. Full article

(This article belongs to the Special Issue Advanced Lasers and Their Applications, 3rd Edition)

► Show Figures

Figure 1

10 pages, 970 KB

Open AccessArticle

Full Bandwidth Time-Domain Intensity Statistical Characteristics of Raman Random Fiber Laser Based on a Temporal Dynamics Controllable Pump

by Zhitao Leng, Mengqiu Fan and Han Wu

Photonics 2025, 12(11), 1108; https://doi.org/10.3390/photonics12111108 - 10 Nov 2025

Viewed by 573

Abstract

The temporal dynamics and statistical characteristics of Raman random fiber lasers are of great significance for studying their physical properties and applications. In this paper, the effect of pump dynamics on the temporal intensity statistical properties of Raman random fiber lasers is experimentally studied under full bandwidth measurements. The measured intensity probability density function (PDF) of the Raman random fiber laser pumped by an ytterbium-doped random fiber laser (YRFL) deviates inward from the exponential distribution. We further use the spectrally filtered YRFL with different temporal dynamics properties as the Raman pump, and the results reveal that the PDF of the Raman random fiber laser deviates outward from the exponential distribution, and the probability of extreme values increases by using a filtered YRFL pump with larger temporal intensity fluctuations. This work provides experimental evidence of the important role of pump properties on the statistics of a random Raman fiber laser, which could be crucial to tailoring the dynamics of random fiber lasers for various applications such as frequency doubling, supercontinuum generation, and laser inertial confinement fusion. Full article

(This article belongs to the Special Issue Advanced Lasers and Their Applications, 3rd Edition)

► Show Figures

Journal Menu

Journal Browser

Advanced Lasers and Their Applications, 3rd Edition

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Related Special Issue

Published Papers (10 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI