Herein, we show the ability to control nonlinear optical nanocrystal orientation and nanostructure orientation at the same time in the Li2O-Nb2O5-SiO2 glass by high repetition rate (100-500 kHz) femtosecond laser direct writing. A self-organized nanostructure with nanoscale phase separation, nonlinear optical nanocrystals embedded in an amorphous network, can be oriented by laser polarization. With the increase of laser power, three modified regimes are revealed. At low laser power, a modified amorphous structure is obtained and has higher HF etching rate than that of the glass substrate. At moderate laser power, polar axes of nanocrystals tend to be perpendicular to laser polarization direction. The range of pulse energy narrows dramatically with the increase of repetition rate. At high laser power, microcrystals are obtained and crystallization is very sensitive to writing mode (the angle between writing direction and laser polarization direction). These findings shed light on the comprehension of ultra-fast laser-matter interaction and provide a new path toward fabricating three-dimensional optical devices.

With the rapid growth of applications requiring laser and optical functional glasses, the optical and mechanical properties of optical functional glass have become more diversified. Furthermore, the uncertainty of glass structure and the continuously adjustable properties of components hinder the rapid research and development of new optical functional glass materials. To eliminate the traditional "trial-and-error" research mode, reduce the cost and cycle of glass material development, and improve the predictability of glass material design and preparation process, the "material genome initiative" was proposed. The material genome initiative combines high-performance computing, data, and experiments to quantitatively and accurately predict the properties of materials using their components, thereby guiding the design and development of new materials. This paper summarizes different theories and current modeling processes of material genetic engineering used in laser and optical functional glasses. These approaches can be divided into physical approaches using the derivation of physical definitions, empirical methods using statistical analysis of experimental data, and theory-empirical approaches that combine theory and experience. Therefore, with respect to laser glass and optical functional glass materials, this paper focuses on the latest progress in material genetic engineering and discusses directions for future development.

Optical fiber constitutes the backbone network of communication in today's world, and has become the underlying framework of human activities. In recent years, the demand for optical fiber transmission bandwidth for the internet of things has increased dramatically, and the function of optical fiber has expanded from a single information transmission to the integration of information transmission and perception. Special silica optical fiber is an important part of achieving this goal. Its research and development have become hot spot. The complex structure and multi-component of specialty fibers pose challenges for their efficient fabrication. This paper summarizes the difficulties, exploration and progress of additive manufacturing technology in the efficient preparation of special silica optical fibers. First, it focuses on how to overcome the ceramicization and collapse of large-scale silica additive manufacturing under the additive manufacturing technology route based on UV curing, and develop suitable additive technology for the preparation of special silica fiber preforms, so that the required special fibers can be drawn. Then, the recent progress in the fabrication of silica fiber preforms using different additive technologies such as direct ink writing and selective laser melting is introduced. Finally, the existing problems and future development trends of additive manufacturing in the manufacture of silica optical fibers are briefly discussed and prospected.

Nd3+ 900 nm laser can be used for pumping Yb3+ laser materials and atmospheric detection. The deep blue laser produced by its frequency doubling has important applications in underwater communications, atomic cooling, biomedicine, laser storage, laser display, and laser processing. However, the realization of Nd3+ 900 nm laser must overcome the problem of Nd3+ 1060 nm transition competition. This article introduces the development history of various Nd3+-doped laser materials 900 nm laser, and briefly summarizes the methods to suppress 1060 nm laser. Combined with the research work of our research group, this article proposes that the key to further increasing the output power of the Nd3+ 900 nm laser is to ensure a lower quenching probability and increase the 900 nm fluorescence branching ratio of the material. By incorporating non-oxygen anion groups into Nd3+ silica glass to adjust the Nd3+ micro-local environment, the Nd3+ 900 nm fluorescence branching ratio is greatly improved. Nd3+-doped fiber with a core-to-clad ratio of 20/125 μm was drawn from the preform with this silica glass as the core. Preliminary master oscillation power amplification results showed that the fiber had a good inhibition effect on amplified spontaneous emission at 1060 nm. This provides a new method for realizing Nd3+ 900 nm high-power laser.

Cluster complexes with steady, effective, and broadband emission hold great promise for applications in bioimaging, sensing, optoelectronics, and lighting. The synthesis of such cluster complexes usually depends on solution processing and wet-chemical deposition approaches, which face considerable difficulties. To synthesize all-inorganic tellurium cluster in supercooled melts (e.g., Tellurium cluster-doped borate glass), the tellurium's morphology is fine-tuned by modifying the glass network topology and melting conditions in this paper. The experimental findings reveal that under a reducing atmosphere, integrating glass with a high degree of network polymerization and alumina dispersion effect regulates the size and shape of clusters to stably form near-infrared active D2h-Te4 clusters and achieve high-efficiency ultra-broadband near-infrared luminescence pumped by 808 nm laser in all-inorganic tellurium cluster D2h-Te4 doped borate glass.

In order to achieve stable luminescence quantum efficiency from cesium lead halide perovskite nanocrystals embedded glasses, this work investigated the effects of water quenching and secondary low-temperature thermal treatment on the structure and optical properties of CsPbBr3 nanocrystals embedded glasses. Results show that water quenching of high-temperature heat-treated glass can restrain the growth of CsPbBr3 nanocrystals, and significantly reduce the photoluminescence quantum efficiency. Then, low-temperature thermal treatment can promote the growth, improve the quality of CsPbBr3 nanocrystals, and enhance their photoluminescence quantum efficiency. The research results have certain reference value for the preparation of cesium lead halide perovskite nanocrystals embedded glasses with stable photoluminescence quantum efficiency and the development of optoelectronic functional devices.

The green color-converted materials are the core components of laser projection display. To date, the high-performance narrowband green color-converted materials for high-quality laser display are still in short supply. In this paper, the commercial narrowband green-emissive β-SiAlON∶Eu2+ phosphor together with a kind of low-melting-glass of new composition are co-sintered on a high thermal conductivity sapphire substrate coated by one-dimensional photonic crystal film, forming an integrated phosphor-in-glass film composite. It is demonstrated that the thermal erosion of β-SiAlON∶Eu2+ is insignificant after low temperature co-sintering. The composite material exhibits the internal quantum efficiency of 55%, full width at half maximum of 54 nm, and excellent resistance to thermal quenching (the integral luminescence intensity at 150 ℃ remains about 90% of that at room temperature). It is also found that the one-dimensional photonic crystal film greatly enhances the forward green luminescence up to about 1.5 times. The luminescence saturation takes place under 9 W/mm2 blue laser irradiation with the corresponding luminous flux of 492 lm, and the latent luminescence saturation mechanism is tentatively analyzed. After coupling with red laser diodes, the color gamut reaches 95.6% NTSC.

Rare earth doped chalcogenide glass-ceramics possess advantages for luminescence regulation because of their low phonon energy and sulfide nanocrystals. Here, 80GeS2·20Ga2S3 chalcogenide glasses and glass-ceramics doped with different mole fractions Er3+ ions were prepared and investigated via advanced structure and performance characterization. Effect of rare earth content and crystallization on the up-conversion luminescence of Er3+ ions was discussed accordingly. The results show that the introduction of Er causes the decreasing glass transition temperature and onset temperature of crystallization peak, leading to the presence of stronger diffraction peaks corresponding to Ga2S3 phase in the samples containing more Er3+ ions. The crystallization of Ga2S3 nanocrystals enhances the up-conversion by nearly 5 times, and the optimal luminescence doping mole fraction increases from 0.75% to 1%.

In this paper, Yb3+/Tm3+ co-doped phosphate glass is prepared using a high-temperature melting method, and the effects of Tm3+ mole fraction and Te4+ mole fraction in the glass matrix on the upconversion luminescence properties of the glass are discussed. The absorption spectrum shows that the absorption positions of Yb3+ and Tm3+ ions in the glass do not interfere with each other at the wavelength of 300?1450 nm. The upconversion luminescence properties of the as-prepared glass samples under 980 nm wavelength laser diode pumping are investigated. The results indicate that Yb3+/Tm3+ has upconversion luminescence peaks at 476 nm (1G4→3H6), 650 nm (1G4→3F4), and 793 nm (3H4→3H6), among which the near-infrared luminescence peak at 793 nm is the strongest. The luminescence intensity at 476 nm is the next highest and the lowest at 650 nm. The intensity of the three abovementioned luminescent peaks can be tuned by adjusting the Tm3+ mole fraction and the Te4+ mole fraction in the glass matrix.

Scintillators that can absorb high-energy photons and convert them into low-energy visible photons are used extensively in fields, including nondestructive inspection, security inspection, and medical imaging. Aiming at the inadequacy of time-consuming and high cost in the preparation process of traditional scintillator crystals, Sn2+-doped borosilicate glasses are synthesized successfully through the traditional melt-quenching approach in this study. The transmission, excitation, and ultraviolet (UV) stimulated emission spectra, X-ray excited luminescence (XEL) spectra, and decay curves of the materials are systematically investigated. The experimental findings that correct heat treatment can efficiently improve the fluorescence intensity of UV and XEL of the sample, and the XEL intensity of the optimal sample reaches 25.1% of that of commercial Bi4Ge3O12 crystal. Furthermore, the transmittance of the sample decreases only moderately under various power X-ray excitation. In addition, it can be restored to the initial level after the thermal treatment again. The synthesized samples endow remarkable fluorescence properties of ultraviolet excitation and X-ray irradiation that have promising potential in X-ray imaging and other fields.

In recent years, narrow-linewidth fiber lasers have attracted extensive attention owing to their application in the fields of beam combination and gravitational wave detection. However, stimulated Brillouin scattering and transverse mode instability seriously limit the power scaling of narrow-linewidth fiber laser. At present, the approaches to improve the power of narrow-linewidth fiber laser mainly focus on the optimization of fiber laser system. In this paper, the research progresses in the ytterbium-doped silica glass fiber for narrow-linewidth fiber laser and amplifier are briefly introduced, and the future development trend of narrow-linewidth fiber laser technology are prospected.

Dy3+-doped, Tb3+-doped and Tb3+/Dy3+ codoped tellurium-germanium-barium (TeO2-GeO2-BaO) glasses are prepared by high temperature melt-quenching method. The total mole fraction of the network formers of both TeO2 and GeO2 is summed up to 66.6 %. The luminescent performances of TeO2-GeO2-BaO glasses are systematically studied by transmittance and photoluminescence spectra. The optimal doping concentration of Dy3+ and Tb3+ ions in TeO2-GeO2-BaO glasses is determined. And the efficient energy transfer process from Dy3+ to Tb3+ ions are observed clearly. The developed TeO2-GeO2-BaO glass is featured with density of over 5.0 g/cm3, decay time of lower 1 ms, and transmittance of reaching 85% in 400-700 nm wavelength regions, which suggest that the investigated TeO2-GeO2-BaO glass is of significance in scintillation application for detection of high-energy rays.

Perovskite quantum dots (QDs) glass has found applications in optoelectronic fields such as solid-state lighting, backlight display, and anti-counterfeiting due to its excellent optical properties and good stability. In this paper, recent progresses in the preparation of perovskite QD doped glasses are introduced, the optical properties of perovskite QDs glasses optimized by glass network structure modulation and metal ion doping are highlighted, and the applications of perovskite QDs glasses in the fields of anti-counterfeiting, optical storage and light illumination are summarized.

This review mainly focuses on the research progress of the preparation of optical functional glass and glass-ceramics by spark plasma sintering technology. Spark plasma sintering is an important technology for achieving rapid densification of powder materials. Using it to prepare optical functional glass and glass-ceramic materials can not only simplify the preparation process, shorten the preparation time, but also expand the research field of optical glass-ceramics. This paper summarizes the glass systems prepared by spark plasma sintering technology. Based on the latest research progress, the effects of different sintering parameters such as temperature, pressure, and sintering holding time on glass shrinkage, final densification, and transparency, as well as the effects of these parameters on other properties of glass materials, are mainly introduced. Finally, the possible development directions in the future are discussed, including digging into the sintering mechanism, reducing or even avoiding carbon contamination, optimizing the preparation process, developing new optical functional composite glass, and exploring new applications.

The mid-infrared band contains extremely important atmospheric infrared windows and the fingerprint regions of many important molecules. The light sources and optical devices in this band have important applications in the fields of optoelectronic countermeasures, environmental monitoring, biological sensing, and medical diagnosis. As a key component of all-fiber mid-infrared lasers, mid-infrared glass fiber gratings have become a recent research hotspot. Fluoride fiber gratings, chalcogenide fiber gratings, and tellurite fiber gratings are the most widely used mid-infrared glass fiber gratings. This paper gives a comprehensive and systematic overview of the performance characteristics, fabrication process, research status, and application fields of the three kinds of fiber gratings, and analyzes the advantages and limitations of the current mid-infrared glass fiber gratings. It provides a reference for further improving the performance of mid-infrared fiber lasers and expanding the application field of mid-infrared fiber gratings.

Visible fiber lasers with visible wavelengths ranging from 380-780 nm have been widely used in lighting, display, medical treatment, astronomy, and other applications. Traditional visible light fiber lasers rely on rare earth ion upconversion to produce visible light laser output, and their efficiency is low. Blue light semiconductor lasers (LD)-pumped rare earth doped gain fibers have recently become the primary approach for generating visible light laser output due to the rapid development of blue light LD. This study introduces the generation methods, the characteristics of blue LD-pumped visible laser, and the recent research progress of blue LD-pumped rare earth ion doped visible fiber laser. Furthermore, it summarizes its application in frequency doubling ultraviolet lasers and the prospects for developing visible light fiber lasers.

Rare earth ion-doped tellurite glasses and optical fibers have significant advantages such as fluorescence properties, good thermal stability against crystallization, low transition temperature, high nonlinearity, high refractive index and strong penetration. With the deepening of the research on tellurite glass, fluorescence sensors based on rare earth ion-doped tellurite glass and optical fibers have attracted much attention in the sensing field due to their fast response, strong anti-electromagnetic interference, high resolution, and good stability. In this paper, the preparation method, characteristics, working principle and application in the field of sensing of rare earth ion-doped tellurite glass and optical fiber are reviewed, three aspects of temperature sensing, pressure sensing and concentration sensing are introduced and the prospect of its sensing applications are prospected.

Fluoride ZBLAN glass fiber has crucial application values in the military, communication, medical and other fields, and the fabrication of ultra-low loss fibers has become a strategic key technology in great power competition. However, the ZBLAN glass crystallization is easy to occur during the melting and cooling process, and the multiple crystallization areas in the fiber will cause the scattering of light transmission, resulting in an actual loss of glass fiber that is 2-3 orders of magnitude higher than the theoretical loss, severely limiting its application value. Therefore, preparing ultra-low loss ZBLAN glass fibers has become a major challenge in optical fibers. The microgravity environment in space can inhibit the convection of melt components caused by gravity, greatly reducing the rate of melt nucleation and crystallite growth and the degree of crystallization during the solidification of ZBLAN glass materials, thereby reducing the optical loss of the material. The National Aeronautics and Space Administration has already conducted several optical fiber manufacturing technology experiments on the international space station. With the completion and operation of China's space station, it is preliminarily feasible to manufacture space fluoride fiber in microgravity. This paper summarizes the main research progress on domestic and overseas space optical fiber manufacturing, introduces the influence of the microgravity environment on the manufacturing of ultra-low lossfluoride fiber and discusses the feasibility of “made in orbit-used on ground”of special optical fibers. This research provides a technical reference for improving the Chinese space manufacturing level and expanding the application field of space science and technology.

As a special infrared optical glass, chalcogenide glass shows great advantages in the application of photonic devices in the mid-infrared band. Laser-induced periodic surface structures, whose periods are close to or less than the incident laser wavelength, have broad application prospects in fabricating micro-optical infrared devices that exceed the diffraction limit. This study investigates the evolution process of the periodic structure induced by femtosecond laser on As2S3 glass with a pulse number using two processing methods, single point and laser direct writing. First, the formation mechanism of two different periodic structures (low and high spatial frequencies) formed under low and high pulse numbers was analyzed. Then, a large-area periodic structure was fabricated on the surface of As2S3 glass using femtosecond laser direct writing technology, and the optical color properties of the periodic structure were tested and explored.

Rare-earth ions with unique stepped energy levels have attracted considerable attention in the field of upconversion luminescence. Rare-earth-doped ultraviolet upconversion materials are effective in realizing ultraviolet short-wavelength compact lasers. However, substantial energy loss occurs in the ultraviolet upconversion process of rare-earth ions, resulting in extremely low ultraviolet upconversion efficiency. Therefore, manufacturing high-power ultraviolet upconversion lasers is difficult, and the practical application of ultraviolet upconversion lasers is limited. By reducing the matrix phonon energy, regulating the matrix microstructure, improving the pumping mode, and adjusting the laser resonator morphology, energy transfer during ultraviolet upconversion can be effectively regulated and the efficiency of ultraviolet upconversion laser can be improved. In this study, the principle of upconversion luminescence, composition of ultraviolet upconversion materials, strategies for enhancing ultraviolet upconversion luminescence, and recent advances in ultraviolet upconversion lasers are reviewed.

Fiber lasers are widely used in industrial processing, military defense, and other fields. The energy distribution of the laser output in fiber lasers is Gaussian-like distribution. This nonuniform energy distribution within the spot diameter affects the consistency of the processing effect at different positions along the spot diameter when applied to lithography, welding, etc. Therefore, homogenizing and shaping Gaussian-like beams in practical applications is greatly significant. Compared with the beam shaping method of the traditional spatial structure, using the all-fiber structure in beam shaping provides a simple structure and good compactness for the fiber lasers. By summarizing the research progress of various scholars over the years, the homogenization and shaping technology of the all-fiber structure is classified into two categories: increasing the components of the high-order mode in the output laser and directly changing the energy distribution of the fundamental mode. In this paper, we present the research status of all-fiber structure beam homogenization and shaping technology and discuss prospects of future development in all-fiber structure beam shaping technology.

This study successfully prepares a transparent KLu2F7∶Er3+/Yb3+ nano-composite glass ceramics using a high melt quenching method. X-ray diffraction was used to characterize the types of nanocrystals precipitated from the glass, and the highest crystallinity was up to 28%. A spectrophotometer was used to verify the optical transmittance of the prepared glass ceramics (approximately 89%). Under 980 nm laser pumping, the upconversion luminescence of the glass ceramic sample was increased by 847 times, and it was found that both the upconversion green and red light belongs to a two-photon process. The fluorescence temperature measurement performance of thermal coupling energy levels 2H11/2 and 4S1/2 of Er3+ was studied using the fluorescence intensity ratio technique in the range of 313-553 K, with the corresponding absolute and relative temperature sensitivity reaching 11.03×10-4 K-1 and 738.45 T-2·K-1, respectively. The results provide a data reference for exploring the properties of fluoride-based glass ceramics in the field of high-temperature sensing.

Temperature is a common physical quantity that significantly affects agricultural production, industrial manufacturing, scientific research, and human life. Therefore, accurate temperature detection is crucial. Conventional temperaturesensors are widely used; however, they are easily affected by environmental factors, particularly conditions of high voltage and strong electric and magnetic fields, which can cause problems such as reduced accuracy and high error. By contrast, optical fiber sensing technology enables sensing in harsh environments and can address the limitations of conventional temperature sensors. Optical fiber fluorescence temperature sensing technology combines optical fiber and fluorescent sensing technologies. It uses optical fibers for light transmission and the temperature-sensitive characteristics of fluorescent material to achieve temperature sensing capability. Moreover, it enables temperature detection in various conditions, including harsh environments, and offers advantages such as strong anti-interference, rapid response, good repeatability, and high sensitivity. This paper reviews optical-fiber probe preparation methods such as doping, coating and deposition, encapsulation, and special optical-fiber splicing methods. In addition, temperature-measurement signal processing methods such as fluorescence intensity, fluorescence intensity ratio, fluorescence lifetime, and fluorescence emission peak wavelength shift methods are discussed. Finally, we list and analyze the advancements in optical fiber temperature probes and present an outlook for future development.