Method for reducing laser processing threshold by adopting cerium-doped glass

Abstract

The invention discloses a method for reducing a laser processing threshold by adopting cerium-doped glass. The method comprises the following steps: 1) selecting quartz glass or borosilicate glass as a glass substrate; 2) preparing the glass substrate selected in the step 1), specifically, 2.1) preparing a precursor liquid; (2.2) entering a mold; 2.3) drying treatment; 2.4) heat treatment and sintering; and 3) laser processing. The Ce < 3 + > ions are doped in the glass substrate, and the light absorption characteristic of the Ce < 3 + > ions in a narrow band gap is utilized, so that the problem of low laser energy absorption efficiency caused by the wide band gap characteristic of the traditional glass substrate is effectively improved, and the energy absorption efficiency of the glass substrate to laser is remarkably improved, which means that the energy absorption efficiency of the glass substrate to laser is greatly improved under the same processing effect. The required laser energy can be greatly reduced, the dependence of a laser processing system on a high-power laser is reduced, thermal damage is greatly reduced, the problems of fusion, microcracks, thermal stress and the like caused by traditional high-intensity laser are avoided, and excessive loss of energy is also avoided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of laser processing, and more particularly, to a method for reducing laser processing threshold by using cerium-doped glass. BACKGROUND

[0002] Optical storage technology is a technology that uses a laser to irradiate a medium to change the physical and chemical properties of the medium through the interaction between the laser and the medium, and stores information. The basic physical principle is that after the storage medium is irradiated by a laser, the properties of the medium (such as reflectivity, polarization direction of reflected light, etc.) change, and the different states of the properties of the medium are mapped to different storage data, and the reading of the storage data is achieved by identifying the changes in the properties of the storage unit.

[0003] In the field of laser processing and optical storage, traditional glass substrates (such as fused quartz and borosilicate glass) have excellent optical transmittance, chemical stability and mechanical strength, and are ideal carriers for optical storage media, but they face many challenges in practical applications. First, traditional glass substrates have a wide band gap, for example, the band gap of commonly used fused quartz glass is as high as 8eV~9eV. This characteristic makes it necessary for the glass substrate to achieve energy conversion through multi-photon absorption during laser processing, and the wide band gap results in very low photon absorption efficiency, requiring the absorption of more photons to reach the energy threshold required for effective processing. Ultimately, the laser processing threshold is significantly high, which means that high-power lasers are needed to complete the processing, increasing equipment energy consumption and the complexity of the processing system. High-power lasers and supporting cooling and optical elements are costly, increasing the construction and operation costs of optical storage systems, and high-power lasers can easily cause local overheating of the glass substrate, which can damage the precision of the micro storage unit and make it difficult to meet the requirements of high-density storage for processing precision, ultimately limiting its application in large-scale data storage.

[0004] To solve the problem of high processing threshold of traditional glass substrates, researchers focus on modifying the glass substrate. During the preparation of the glass substrate, rare earth ions with special optical properties are doped, and the characteristic energy level transition characteristics of the rare earth ions are used to improve the absorption efficiency of the glass substrate for laser energy. The band gap of the rare earth ions is narrower, and fewer photons are needed for transition during multi-photon absorption. The rare earth ions provide initial free electrons, which then trigger avalanche ionization to modify the material, thereby reducing the absorption threshold of laser energy and ultimately achieving a reduction in the processing threshold. The core advantage of this scheme is that only a small amount of rare earth elements is needed to change the laser absorption characteristics of the glass substrate, which can seamlessly adapt to the existing application scenarios of optical storage media.

[0005] Currently, the traditional process for adding rare earth elements to glass substrates is the high-temperature melting method. The high temperature of the high-temperature melting method easily causes rare earth ions to agglomerate, reducing the utilization rate of laser energy and resulting in a high laser processing threshold. The high laser processing threshold (energy) easily causes irreversible defects such as melting, microcracks, and thermal stress on the glass substrate, which seriously affects the accuracy and lifespan of the optical storage medium.

[0006] Therefore, doping rare earth ions into glass substrates and effectively suppressing the aggregation of rare earth ions in the glass substrates has become an important research direction for reducing the laser processing threshold of glass substrates. Summary of the Invention

[0007] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a method for reducing the laser processing threshold using cerium-doped glass, by adding Ce to the glass substrate. 3+ Ions, utilizing Ce 3+ The light absorption characteristics of ions in a narrow bandgap significantly improve the energy absorption efficiency of the glass substrate for laser, thereby reducing the laser processing threshold.

[0008] To achieve the above objectives, according to the present invention, a method for reducing the laser processing threshold using cerium-doped glass is provided, comprising the following steps: 1) Select a glass substrate, wherein the glass substrate is quartz glass or borosilicate glass; 2) Preparation of the glass substrate selected in step 1), as follows: 2.1) Preparation of precursor solution: Based on the selected glass substrate type, prepare a precursor solution containing a silicon source and a cerium source, wherein the precursor solution contains Ce. 3+ ; 2.2) Molding: Place the precursor fluid into the mold; 2.3) Drying treatment: The mold containing the precursor is placed in a vacuum drying oven to dry and obtain a dry gel; 2.4) Heat treatment and sintering: First, the dry gel is heated in a muffle furnace to remove residual ethanol and nitrate. Then, the dry gel is transferred to a tube furnace and sintered in a vacuum environment and reducing atmosphere. Subsequently, it is cooled to room temperature in the tube furnace to obtain a glass substrate. 3) Laser processing: The laser processing system emits laser light to process the glass substrate prepared in step 2) into an optical storage medium.

[0009] Preferably, in step 1), the glass substrate is quartz glass, and the general formula of the quartz glass is aSiO2-xCe. 3+ ; Where a and x are the mole fractions of each component, 0.98≤a<1, 0<x≤0.02, and a+x=1.

[0010] This precise control over composition allows for the production of quartz glass with Ce doping. 3+ After ionization, it can maintain its excellent optical transmittance. Quartz glass itself has extremely high transmittance, which can be improved by controlling Ce. 3+ The amount of ion doping can enhance the absorption capacity of quartz glass for specific wavelengths of laser light without significantly reducing its optical transmittance. An appropriate amount of Ce... 3+ Ions can effectively absorb photons, improving processing efficiency, without causing Ce to deteriorate due to excessive doping levels. 3+ To address defects such as ion aggregation inside the glass, decreased optical uniformity, and reduced light transmittance, Ce... 3+ It is uniformly dispersed in the quartz glass substrate, continuously and efficiently absorbing laser energy, thereby steadily reducing the laser processing threshold.

[0011] By precisely controlling Ce 3+ The amount of ion doping allows for more precise control over the laser processing process. In laser processing, the absorption efficiency of the glass substrate directly affects the processing accuracy and quality. Appropriate amounts of Ce... 3+ Ions enable quartz glass to produce a more uniform heat distribution under laser irradiation, reducing cracks and defects caused by thermal stress concentration. This uniform heat distribution facilitates finer processing features, allowing for the precise formation of tiny memory cells and increased storage density in the manufacture of high-density optical storage media. Furthermore, precise control of the doping level can reduce energy waste during processing, as excessive doping can lead to unnecessary energy absorption and scattering, while appropriate doping ensures efficient energy utilization and improves processing efficiency.

[0012] By setting Ce = 0 < x ≤ 0.02 3+ The doping amount, without affecting the performance of the glass substrate, precisely plays its role in improving laser energy absorption, achieving the dual advantages of "high-performance glass substrate + low processing threshold", and solving the contradiction of reducing the threshold and maintaining the performance of the glass substrate in traditional doping schemes.

[0013] Preferably, in step 2.1), the silicon source is tetraethyl orthosilicate, and the precursor fluid is a mixture of precursor fluid I and precursor fluid II. The precursor solution I is an acidic solution formed by dissolving tetraethyl orthosilicate in ethanol and adjusting the pH value to pH=2~3 with hydrochloric acid, and the molar concentration of tetraethyl orthosilicate in the precursor solution I is 1mol / L~2mol / L; The precursor solution II is a solution formed by dissolving cerium nitrate and oxalic acid in deionized water, and the molar concentration of cerium ions in the precursor solution II is 0.1 mol / L to 0.136 mol / L; The volume V of the precursor fluid IIⅡ The volume V of the precursor fluid I Ⅰ The ratio is: V Ⅱ / V Ⅰ ≤0.15.

[0014] Tetraethyl orthosilicate (TEO), as the core silicon source for preparing glass substrates, needs to undergo a hydrolysis reaction to generate a silanol intermediate, followed by a polycondensation reaction to form a gel (which is then dried into a dry gel and sintered into a glass substrate). Hydrochloric acid is used as a catalyst to accelerate the hydrolysis of TEO in an ethanol system. An acidic environment with a pH of 2-3 significantly increases the hydrolysis rate while preventing uneven silicon source distribution due to excessively slow hydrolysis or localized agglomeration due to excessively rapid hydrolysis, ensuring uniform dispersion of the silicon source in the precursor solution. Uneven hydrolysis of TEO will lead to differences in silicon distribution in the subsequent dry gel and sintered glass substrate, potentially causing Ce2+ degradation. 3+ Localized agglomeration reduces the optical homogeneity of the glass. Adjusting the pH to 2-3 with hydrochloric acid ensures uniform hydrolysis of the silicon source, allowing it to react with Ce-containing compounds. 3+ The components are uniformly mixed in the precursor liquid to avoid Ce2 oxidation caused by uneven silicon source. 3+ The imbalance in distribution ultimately ensures the stable absorption efficiency of laser energy by the glass substrate.

[0015] If the pH is not adjusted or deviates from the range of 2-3, the hydrolysis reaction of tetraethyl orthosilicate is prone to getting out of control: too high a pH (neutral or alkaline) will cause the hydrolysis products to rapidly condense, causing the precursor fluid to gel prematurely; too low a pH (strongly acidic) may corrode subsequent process equipment or lead to over-hydrolysis and the generation of impurities. Adjusting the pH to the weakly acidic range of 2-3 with hydrochloric acid can promote hydrolysis while precisely controlling the reaction rate, ensuring that the precursor fluid remains stable and free from precipitation or gelation.

[0016] Oxalic acid can prevent Ce 3+ Premature sedimentation.

[0017] By limiting the molar concentration of silicon source in precursor solution I to 1 mol / L~2 mol / L and the molar concentration of cerium ions in precursor solution II to 0.1 mol / L~0.136 mol / L, and V Ⅱ / V Ⅰ ≤0.15, can precisely control Ce 3+ The final doping amount and distribution uniformity in the glass substrate ensure Ce 3+ By fully leveraging the absorption characteristics in the narrow bandgap, the energy absorption efficiency of the glass substrate for laser is further improved. Compared with the scheme without limiting the concentration and ratio, the laser processing threshold reduction effect is more stable.

[0018] Preferably, in step 2.4), the heating temperature in the muffle furnace is 420°C to 480°C, the heating time is 1 h to 2 h, the sintering temperature in the tube furnace is 1800°C to 1900°C, and the sintering time is 2 h to 4 h.

[0019] The heating temperature is 420°C to 480°C. This temperature range can not only fully volatilize and remove the residual ethanol (organic solvent) and nitrate (cerium nitrate from precursor solution II) in the xerogel, but also avoid the residual impurities caused by too low temperature (affecting the optical uniformity of the glass) or premature sintering and cracking of the xerogel caused by too high temperature (destroying the subsequent forming structure), providing a pure and complete xerogel matrix for the subsequent tube furnace sintering and laying the foundation for the low laser processing threshold of the glass substrate. The sintering temperature of 1800°C to 1900°C in the tube furnace highly matches the melting and sintering characteristics of quartz glass, enabling the full conversion of the xerogel into a dense and transparent quartz glass, avoiding the pores in the glass caused by insufficient sintering temperature (resulting in laser scattering loss); at the same time, this temperature combined with the vacuum-reducing atmosphere in the tube furnace can effectively inhibit Ce 3+ from being oxidized to Ce 4+ at high temperature and losing the light absorption ability in the narrow bandgap, ensuring that Ce 3+ is uniformly dispersed in the quartz glass substrate and steadily plays the role of laser energy absorption, thereby continuously and reliably reducing the laser processing threshold.

[0020] Preferably, the glass substrate is borosilicate glass, and the general formula of the borosilicate glass is: aSiO2 - bB2O3 - cNa2O - dAl2O3 - eBaO - fCaO - xCe 3+ ; where a, b, c, d, e, f, x are the molar fractions of each component, and 0.6 < a < 0.8, 0.1 < b < 0.2, 0.05 < c < 0.15, 0.01 < d < 0.05, 0.005 < e < 0.05, 0.005 < f < 0.05, 0 < x ≤ 0.02, and a + b + c + d + e + f + x = 1.

[0021] By limiting the molar fraction range of each main component in the borosilicate glass, not only the excellent properties of the borosilicate glass itself, such as low thermal expansion coefficient, good chemical stability and easy processability, are retained, but also the optical transmittance required for the glass substrate as an optical storage medium is ensured by the SiO2 ratio of a > 0.6; at the same time, the doping amount of Ce 3+ is limited to 0 < x ≤ 0.02. On the premise of not destroying the main structure of the glass substrate, for Ce 3+Uniform dispersion provides space for the full play of the light absorption characteristics in the narrow bandgap, effectively improving the problem of low laser energy absorption efficiency caused by the wide bandgap of traditional borosilicate glass, and achieving the dual guarantee of the inherent advantages of the glass substrate and the low processing threshold.

[0022] The limitation of 0 < x ≤ 0.02 strictly controls the doping upper limit of Ce 3+ in borosilicate glass. At the same time, by regulating the ratio of fluxes such as Na2O and Al2O3 to network modifiers (0.05 < c < 0.15, 0.01 < d < 0.05), the compactness and uniformity of the glass network structure are optimized, effectively avoiding the Ce 3+ agglomeration and glass phase separation problems caused by too high ion concentration or imbalance of glass substrate components in the traditional rare earth doping process. The uniform dispersion of Ce 3+ ensures the stable absorption efficiency of laser energy, and further makes the reduction effect of the laser processing threshold more reliable, avoiding the fluctuation of the processing threshold caused by uneven doping.

[0023] Preferably, in step 2.1), the precursor solution is formed by mixing precursor solution A, precursor solution B, precursor solution C and precursor D, and: The precursor solution A is an acidic solution formed by dissolving tetraethyl orthosilicate in an ethanol solution and adjusting the pH value to pH = 2 - 3 with hydrochloric acid. In the precursor solution A, the molar concentration of tetraethyl orthosilicate is 1.352 mol / L - 1.672 mol / L; The precursor solution B is formed by dissolving an aluminum source in ethanol and adding hydrochloric acid to prevent the precipitation of the aluminum source. In the precursor solution B, the molar concentration of the aluminum source is 0.713 mol / L - 0.875 mol / L; The precursor solution C is formed by dissolving a boron source in ethanol. In the precursor solution C, the molar concentration of the boron source is 1.426 mol / L - 1.713 mol / L; The precursor solution D is formed by dissolving sodium nitrate, barium nitrate, calcium nitrate, cerium nitrate and oxalic acid in an ethanol solution. In the precursor solution D, the concentration of nitrate ions is 0.9 mol / L - 1.2 mol / L; the molar concentration of cerium ions is not more than 0.085 mol / L; The volume ratio of precursor solution B, precursor solution D, precursor solution C to precursor solution A is 1:(3.7 - 4):2.5:5.8.

[0024] By controlling the concentration of tetraethyl orthosilicate, the content of silicon dioxide in the glass substrate can be ensured to be stable, maintaining the basic structure and optical properties of the glass; by controlling the concentration of other metal ions, the chemical instability of the glass substrate caused by excessive impurities can be avoided.

[0025] By incorporating the silicon, aluminum, boron, nitrate, and cerium sources required for borosilicate glass into four independent precursor liquids, chemical reactions caused by direct contact between different components in the initial preparation stage can be effectively avoided (such as premature precipitation of aluminum and boron sources, and imbalance of complexation between cerium sources and other metal ions). Simultaneously, each precursor liquid has a specific process defined for it. For example, precursor liquid B uses hydrochloric acid to prevent aluminum source precipitation, and precursor liquid A uses hydrochloric acid to adjust the pH to 2-3 to promote silicon source hydrolysis, ensuring the stability of components within a single system. Furthermore, the volume ratio of these four independent precursor liquids is carefully mixed to further prevent gelation or stratification of the precursor liquids due to ratio fluctuations, providing a uniform and stable raw material basis for subsequent sintering.

[0026] The volume ratios of the four precursor fluids and the molar concentration ranges of each component ensure Ce 3+ The cerium ion agglomeration and glass phase separation problems that easily occur in traditional multi-component doping can be uniformly dispersed with the borosilicate glass bulk component, thus avoiding the problems of cerium ion agglomeration and glass phase separation that are prone to occur in traditional multi-component doping. 3+ It can fully utilize the light absorption characteristics in the narrow bandgap, steadily improve the laser energy absorption efficiency, and thus reliably reduce the optical inhomogeneity and structural defects of the glass substrate, thereby lowering the laser processing threshold.

[0027] Preferably, in step 2.4), the heating temperature in the muffle furnace is 200℃~300℃ and the heating time is 1h~2h, and the sintering temperature in the tube furnace is 400℃~480℃ and the sintering time is 2h~4h.

[0028] The muffle furnace heating temperature is 200℃~300℃. This range is highly compatible with the composition characteristics of the borosilicate glass precursor liquid (composed of a mixture of precursor liquids A / B / C / D). This range can fully volatilize and remove residual ethanol and nitrate ions in the dry gel, while avoiding the problem of impurities remaining due to excessively low temperatures (affecting the optical uniformity of the glass and increasing laser scattering loss) or premature shrinkage and cracking of the dry gel due to excessively high temperatures (such as exceeding 300℃) (damaging the integrity of the matrix for subsequent sintering). This provides a pure and complete dry gel matrix for tube furnace sintering.

[0029] The sintering temperature of 400℃~480℃ in the tube furnace can achieve a complete transformation of dry gel into dense, transparent borosilicate glass, avoiding the internal porosity of the glass due to insufficient sintering temperature (causing laser energy scattering loss), or the excessive melting and deformation of the glass and component volatilization due to excessively high temperature (such as exceeding 480℃). At the same time, this temperature, combined with the vacuum-reducing atmosphere of the tube furnace, can effectively suppress Ce. 3+ It is oxidized to Ce at high temperature. 4+ This results in the loss of light absorption capability in narrow band gaps, ensuring Ce 3+ It is uniformly dispersed in a borosilicate glass substrate and stably exerts its laser energy absorption effect, thereby continuously and reliably reducing the laser processing threshold.

[0030] Preferably, in step 2.3), the thickness of the dry gel is 2mm to 3mm.

[0031] The limited dry gel thickness of 2mm to 3mm ensures that the precursor liquid is fully spread on the mold surface, forming a uniform dry gel without any missed areas or localized accumulation. It also prevents defects such as cracking and delamination caused by an excessively thin dry gel (less than 2mm) or an excessively thick dry gel (greater than 3mm) leading to significant differences in the evaporation rates of moisture / solvent between the inside and outside of the mold during drying. A complete and uniform dry gel is fundamental for subsequent heat treatment and sintering to form a high-quality glass substrate, effectively reducing laser scattering loss caused by defects in the glass substrate.

[0032] Within a dry gel thickness range of 2mm to 3mm, Ce in the precursor fluid 3+ It can be uniformly dispersed in the dry gel, and after subsequent drying and sintering, Ce 3+ It can be uniformly integrated into the glass substrate, avoiding localized Ce buildup caused by uneven dry gel thickness. 3+ The problem lies in concentrations that are too high (causing ion aggregation) or too low (failing to fully utilize photon absorption). 3+ The uniform distribution of the laser energy ensures a stable and consistent absorption efficiency, thereby making the reduction of the laser processing threshold more reliable and avoiding fluctuations in processing quality caused by uneven absorption.

[0033] Preferably, in step 2.3), the vacuum drying temperature is 35℃~50℃, and the vacuum drying time is 4h~6h.

[0034] By precisely controlling the vacuum drying temperature, it is possible to ensure uniform curing of the degel during the drying process, avoiding cracking or peeling caused by uneven drying. In the preparation of glass substrates, the uniformity of the degel is crucial for subsequent heat treatment and laser processing. By controlling the vacuum drying temperature within the range of 35℃ to 50℃, it is ensured that the degel will not experience thermal stress due to excessively high temperatures, nor will it be incompletely dried due to excessively low temperatures. This precise control not only improves the quality of the degel but also provides a solid foundation for subsequent heat treatment and laser processing.

[0035] By precisely controlling the vacuum drying temperature, the solvents (ethanol, water) in the dry gel can be efficiently removed through gentle heating and a vacuum environment, avoiding the formation of bubbles and pores (causing laser scattering loss) during subsequent sintering due to solvent residue. It also avoids the problems of low drying efficiency and solvent residue caused by excessively low temperature (such as below 35°C) or excessively high temperature (such as above 50°C) causing excessive differences in solvent evaporation rates inside and outside the dry gel, which can lead to structural defects such as cracking and delamination of the dry gel.

[0036] Preferably, in step 3), the laser processing system includes a laser and, sequentially arranged along the optical path of the laser emitted by the laser, an energy control module, a polarization control module, a reflector, an objective lens, and a three-dimensional displacement stage. The energy control module is used to regulate the output energy of the laser, the polarization control module is used to regulate the polarization state of the laser, the reflector is used to reflect the laser to the objective lens, the three-dimensional displacement stage is used to support the glass substrate and adjust the processing area of ​​the glass substrate, and the objective lens is used to focus the laser onto the glass substrate.

[0037] The energy control module can specifically adjust the output energy of the laser to adapt it to cerium-doped glass substrates (quartz glass or borosilicate glass). 3+ The improved laser energy absorption efficiency after doping allows for processing without requiring excessively high power output, avoiding energy waste and precisely matching the reduced processing threshold of the cerium-doped glass. Simultaneously, the polarization control module regulates the laser polarization state. The synergistic effect of these two mechanisms ensures that laser energy is efficiently applied to the processing area of ​​the glass substrate, fully realizing the technological benefits of the reduced processing threshold from the cerium-doped glass and avoiding the problem of artificially high processing thresholds caused by uncontrollable parameters in traditional laser systems.

[0038] The optical path design of the reflector and objective lens can accurately reflect and focus the laser onto the glass substrate, ensuring the positioning accuracy of the laser action point and meeting the high precision requirements of optical storage media for micro-processed structures (such as optical storage units); the three-dimensional displacement stage can flexibly support the glass substrate and adjust the processing area to achieve stable processing of large areas and multiple positions, avoiding positional deviations caused by manual adjustment.

[0039] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1) The method of reducing the laser processing threshold using cerium-doped glass in this invention involves doping Ce into the glass substrate. 3+ Ions, utilizing Ce 3+ The narrow bandgap light absorption characteristics of ions effectively improve the low laser energy absorption efficiency of traditional glass substrates (such as quartz glass and borosilicate glass) caused by their wide bandgap characteristics, significantly increasing the energy absorption efficiency of the glass substrate for lasers. This means that the required laser energy can be greatly reduced to achieve the same processing effect, thereby reducing the dependence of laser processing systems on high-power lasers.

[0040] 2) The method of lowering the laser processing threshold using cerium-doped glass in this invention, through precise control of steps such as the preparation, drying, and heat treatment of the precursor fluid, enables the use of cerium-doped glass to lower the laser processing threshold. 3+ Ions are more evenly distributed and bound within the glass substrate. Uniformly distributed Ce 3+Ions not only help improve the absorption efficiency of laser energy by the glass substrate, but also maintain its good optical homogeneity and transparency. During laser processing, laser energy can act more uniformly on the glass substrate, reducing processing defects caused by inhomogeneities in the substrate's optical properties, such as uneven thermal expansion and phase transitions in the processing area, thereby improving processing accuracy. This is crucial for manufacturing high-density, high-precision optical storage media, effectively improving their quality and performance.

[0041] 3) The method of lowering the laser processing threshold using cerium-doped glass in this invention allows for the use of lower-power lasers, reducing the need for complex optical components, cooling systems, and power supply systems. High-power lasers typically require large cooling systems to ensure stable operation, while low-power lasers can use relatively simple and small cooling systems. Furthermore, low-power lasers have lower precision requirements for optical components, allowing the use of lower-cost and simpler optical components to construct the laser processing system. This not only reduces the construction cost of the laser processing system but also simplifies its structure, improves its reliability and stability, and facilitates maintenance and operation. For small optical storage media processing enterprises or laboratories, the simplified laser processing system is easier to build and use, lowers the technical threshold, and promotes the widespread adoption and application of laser processing technology in the field of optical storage.

[0042] 4) The method of using cerium-doped glass to reduce the laser processing threshold in this invention reduces heat input at the source and avoids excessive heat accumulation by lowering the laser processing threshold; through precise control of the preparation process, the cerium-doped glass... 3+ It can be uniformly dispersed within the glass substrate, and the laser energy is absorbed synchronously throughout the glass substrate, resulting in a smoother heat distribution and no significant thermal gradient differences, thus suppressing thermal damage at the microscopic level. The low energy input only adapts the glass substrate to the optical storage requirements, preventing melting and deformation; the smooth heat distribution ensures more uniform thermal expansion and contraction of the glass substrate, eliminating stress concentration and the possibility of microcracks; simultaneously, the heat effect is limited to the processing point, leaving the surrounding glass substrate unaffected, resulting in no residual thermal stress after processing, ensuring the precision and long-term stability of the optical storage medium. Attached Figure Description

[0043] Figure 1 This is a process flow diagram of the method for reducing the laser processing threshold using cerium-doped glass according to the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0045] Example 1 The method for reducing the laser processing threshold using cerium-doped glass includes the following steps: 1) Select a glass substrate, wherein the glass substrate is quartz glass, and the general formula of the quartz glass is aSiO2-xCe. 3+ Where a and x are the mole fractions of each component, a = 0.999 and x = 0.001.

[0046] 2) Preparation of the glass substrate selected in step 1), as follows: 2.1) Preparation of precursor solution: Based on the selected glass substrate type, prepare a precursor solution containing a silicon source and a cerium source, wherein the precursor solution contains Ce. 3+ The silicon source is tetraethyl orthosilicate, and the precursor fluid is a mixture of precursor fluid I and precursor fluid II. The precursor solution I is an acidic solution formed by dissolving tetraethyl orthosilicate in ethanol and adjusting the pH value to pH=2 with hydrochloric acid, and the molar concentration of the silicon source in the precursor solution I is 2 mol / L; The precursor solution II is a solution formed by dissolving cerium nitrate and oxalic acid in deionized water, and the molar concentration of cerium ions in the precursor solution II is 0.1 mol / L; The volume V of the precursor fluid II Ⅱ The volume V of the precursor fluid I Ⅰ The ratio is: V Ⅱ / V Ⅰ =0.002.

[0047] 2.2) Placement into mold: Take the precursor fluid and place it into the mold.

[0048] 2.3) Drying treatment: The mold containing the dry gel is placed in a vacuum drying oven and dried at a temperature of 35°C for 6 hours to obtain the dry gel, which has a thickness of 2 mm.

[0049] 2.4) Heat treatment and sintering: The dry gel is first heated in a muffle furnace to remove residual ethanol and nitrate. Then the dry gel is transferred to a tube furnace and sintered in a vacuum environment and reducing atmosphere. Subsequently, it is cooled to room temperature in the tube furnace to obtain a glass substrate. The heating temperature in the muffle furnace is 420℃ and the heating time is 1h. The sintering temperature in the tube furnace is 1800℃ and the sintering time is 4h.

[0050] 3) Laser processing: The laser processing system uses a near-infrared femtosecond laser to laser process the glass substrate prepared in step 2) into an optical storage medium.

[0051] In step 3), the laser processing system includes a femtosecond laser and, along the optical path of the near-infrared femtosecond laser emitting a wavelength of 1030 nm, an energy control module, a polarization control module, a reflector, an objective lens, and a three-dimensional displacement stage arranged sequentially. The energy control module is used to regulate the output energy of the near-infrared femtosecond laser, the polarization control module is used to regulate the polarization state of the near-infrared femtosecond laser, the reflector is used to reflect the near-infrared femtosecond laser to the objective lens, the three-dimensional displacement stage is used to support the glass substrate and adjust the processing area of ​​the glass substrate, and the objective lens is used to focus the near-infrared femtosecond laser onto the glass substrate. The numerical aperture of the objective lens is 0.65 NA.

[0052] Example 2 The method for reducing the laser processing threshold using cerium-doped glass includes the following steps: 1) Select a glass substrate, wherein the glass substrate is quartz glass, and the general formula of the quartz glass is aSiO2-xCe. 3+ Where a and x are the mole fractions of each component, a = 0.99 and x = 0.01.

[0053] 2) Preparation of the glass substrate selected in step 1), as follows: 2.1) Preparation of precursor solution: Based on the selected glass substrate type, prepare a precursor solution containing a silicon source and a cerium source, wherein the precursor solution contains Ce. 3+ The silicon source is tetraethyl orthosilicate, and the precursor fluid is a mixture of precursor fluid I and precursor fluid II. The precursor solution I is an acidic solution formed by dissolving tetraethyl orthosilicate in ethanol and adjusting the pH value to pH=3 with hydrochloric acid, and the molar concentration of the silicon source in the precursor solution I is 1.5 mol / L; The precursor solution II is a solution formed by dissolving cerium nitrate and oxalic acid in deionized water, and the molar concentration of cerium ions in the precursor solution II is 0.101 mol / L; The volume V of the precursor fluid II Ⅱ The volume V of the precursor fluid IⅠ The ratio is: V Ⅱ / V Ⅰ =0.15.

[0054] 2.2) Placement into mold: Take the precursor fluid and place it into the mold.

[0055] 2.3) Drying treatment: The mold containing the dry gel is placed in a vacuum drying oven and dried at a temperature of 40°C for 5 hours to obtain the dry gel with a thickness of 2.5 mm.

[0056] 2.4) Heat treatment and sintering: The dry gel is first heated in a muffle furnace to remove residual ethanol and nitrate. Then the dry gel is transferred to a tube furnace and sintered in a vacuum environment and reducing atmosphere. Subsequently, it is cooled to room temperature in the tube furnace to obtain a glass substrate. The heating temperature in the muffle furnace is 450℃ and the heating time is 1.5h. The sintering temperature in the tube furnace is 1700℃ and the sintering time is 3h.

[0057] 3) Laser processing: The laser processing system uses a near-infrared femtosecond laser to laser process the glass substrate prepared in step 2) into an optical storage medium.

[0058] In step 3), the laser processing system includes a femtosecond laser and, along the optical path of the near-infrared femtosecond laser emitting a wavelength of 1030 nm, an energy control module, a polarization control module, a reflector, an objective lens, and a three-dimensional displacement stage arranged sequentially. The energy control module is used to regulate the output energy of the near-infrared femtosecond laser, the polarization control module is used to regulate the polarization state of the near-infrared femtosecond laser, the reflector is used to reflect the near-infrared femtosecond laser to the objective lens, the three-dimensional displacement stage is used to support the glass substrate and adjust the processing area of ​​the glass substrate, and the objective lens is used to focus the near-infrared femtosecond laser onto the glass substrate. The numerical aperture of the objective lens is 0.65 NA.

[0059] Example 3 The method for reducing the laser processing threshold using cerium-doped glass includes the following steps: 1) Select a glass substrate, wherein the glass substrate is quartz glass, and the general formula of the quartz glass is aSiO2-xCe. 3+ Where a and x are the mole fractions of each component, a = 0.98 and x = 0.02.

[0060] 2) Preparation of the glass substrate selected in step 1), as follows: 2.1) Preparation of precursor solution: Based on the selected glass substrate type, prepare a precursor solution containing a silicon source and a cerium source, wherein the precursor solution contains Ce. 3+The silicon source is tetraethyl orthosilicate, and the precursor fluid is a mixture of precursor fluid I and precursor fluid II. The precursor solution I is an acidic solution formed by dissolving tetraethyl orthosilicate in ethanol and adjusting the pH value to pH=2.8 with hydrochloric acid, and the molar concentration of the silicon source in the precursor solution I is 1 mol / L; The precursor solution II is a solution formed by dissolving cerium nitrate and oxalic acid in deionized water, and the molar concentration of cerium ions in the precursor solution II is 0.136 mol / L. The volume V of the precursor fluid II Ⅱ The volume V of the precursor fluid I Ⅰ The ratio is: V Ⅱ / V Ⅰ =0.15.

[0061] 2.2) Placement into mold: Take the precursor fluid and place it into the mold.

[0062] 2.3) Drying treatment: The mold containing the dry gel is placed in a vacuum drying oven and dried at a temperature of 50°C for 4 hours to obtain the dry gel, which has a thickness of 3 mm.

[0063] 2.4) Heat treatment and sintering: The dry gel is first heated in a muffle furnace to remove residual ethanol and nitrate. Then the dry gel is transferred to a tube furnace and sintered in a vacuum environment and reducing atmosphere. Subsequently, it is cooled to room temperature in the tube furnace to obtain a glass substrate. The heating temperature in the muffle furnace is 480℃ and the heating time is 2h. The sintering temperature in the tube furnace is 1900℃ and the sintering time is 2h.

[0064] 3) Laser processing: The laser processing system uses a near-infrared femtosecond laser to laser process the glass substrate prepared in step 2) into an optical storage medium.

[0065] In step 3), the laser processing system includes a femtosecond laser and, along the optical path of the near-infrared femtosecond laser emitting a wavelength of 1030 nm, an energy control module, a polarization control module, a reflector, an objective lens, and a three-dimensional displacement stage arranged sequentially. The energy control module is used to regulate the output energy of the near-infrared femtosecond laser, the polarization control module is used to regulate the polarization state of the near-infrared femtosecond laser, the reflector is used to reflect the near-infrared femtosecond laser to the objective lens, the three-dimensional displacement stage is used to support the glass substrate and adjust the processing area of ​​the glass substrate, and the objective lens is used to focus the near-infrared femtosecond laser onto the glass substrate. The numerical aperture of the objective lens is 0.65 NA.

[0066] Example 4 The method for reducing the laser processing threshold using cerium-doped glass includes the following steps: 1) Select a glass substrate, wherein the glass substrate is borosilicate glass, and the general formula of the borosilicate glass is: aSiO2-bB2O3-cNa2O-dAl2O3-eBaO-fCaO-xCe 3+ Where a, b, c, d, e, f, and x are the mole fractions of each component, and a = 0.679, b = 0.15, c = 0.1, d = 0.03, e = 0.02, f = 0.02, and x = 0.001.

[0067] 2) Preparation of the glass substrate selected in step 1), as follows: 2.1) Preparation of precursor solution: Based on the selected glass substrate type, prepare a precursor solution containing a silicon source and a cerium source, wherein the precursor solution contains Ce. 3+ The precursor fluid is composed of precursor fluid A, precursor fluid B, precursor fluid C, and precursor D, and: The precursor fluid A is an acidic solution formed by dissolving tetraethyl orthosilicate in an ethanol solution and adjusting the pH value to pH=2 with hydrochloric acid. The molar concentration of tetraethyl orthosilicate in the precursor fluid A is 1.672 mol / L. The precursor solution B is formed by dissolving an aluminum source in ethanol and adding hydrochloric acid to prevent the aluminum source from precipitating. In the precursor solution B, the molar concentration of the aluminum source is 0.875 mol / L; the aluminum source is aluminum isopropoxide. The precursor solution C is formed by dissolving a boron source in ethanol, and the molar concentration of the boron source in the precursor solution C is 1.713 mol / L; the boron source is trimethyl borate. The precursor fluid D is formed by dissolving sodium nitrate, barium nitrate, calcium nitrate, cerium nitrate, and beryl acid in an ethanol solution, and the concentration of nitrate ions in the precursor fluid D is 0.9 mol / L; the molar concentration of cerium ions is 0.004 mol / L. The volume ratio of precursor body fluid B, precursor body fluid D, precursor body fluid C to precursor body fluid A is 1:3.7:2.5:5.8.

[0068] 2.2) Placement into mold: Take the precursor fluid and place it into the mold.

[0069] 2.3) Drying treatment: The mold containing the dry gel is placed in a vacuum drying oven and dried at a temperature of 35°C for 6 hours to obtain the dry gel, which has a thickness of 2.5 mm. 2.4) Heat treatment and sintering: The dry gel is first heated in a muffle furnace to remove residual ethanol and nitrate. Then the dry gel is transferred to a tube furnace and sintered in a vacuum environment and reducing atmosphere. Subsequently, it is cooled to room temperature in the tube furnace to obtain a glass substrate. The heating temperature in the muffle furnace is 200℃ and the heating time is 2h. The sintering temperature in the tube furnace is 400℃ and the sintering time is 4h.

[0070] 3) Laser processing: The laser processing system uses ultraviolet laser to process the glass substrate prepared in step 2) into an optical storage medium.

[0071] In step 3), the laser processing system includes an ultraviolet laser and, along the optical path of the ultraviolet laser emitted by the ultraviolet laser, an energy control module, a polarization control module, a reflector, an objective lens, and a three-dimensional displacement stage arranged sequentially. The energy control module is used to regulate the output energy of the ultraviolet laser, the polarization control module is used to regulate the polarization state of the near-ultraviolet laser, the reflector is used to reflect the ultraviolet laser to the objective lens, the three-dimensional displacement stage is used to support the glass substrate and adjust the processing area of ​​the glass substrate, and the objective lens is used to focus the ultraviolet laser onto the glass substrate.

[0072] Example 5 The method for reducing the laser processing threshold using cerium-doped glass includes the following steps: 1) Select a glass substrate, wherein the glass substrate is borosilicate glass, and the general formula of the borosilicate glass is: aSiO2-bB2O3-cNa2O-dAl2O3-eBaO-fCaO-xCe 3+ Where a, b, c, d, e, f, and x are the mole fractions of each component, and a = 0.67, b = 0.15, c = 0.1, d = 0.03, e = 0.02, f = 0.02, and x = 0.01.

[0073] 2) Preparation of the glass substrate selected in step 1), as follows: 2.1) Preparation of precursor solution: Based on the selected glass substrate type, prepare a precursor solution containing a silicon source and a cerium source, wherein the precursor solution contains Ce. 3+ The precursor fluid is composed of precursor fluid A, precursor fluid B, precursor fluid C, and precursor D, and: The precursor fluid A is an acidic solution formed by dissolving tetraethyl orthosilicate in an ethanol solution and adjusting the pH value to pH=2.5 with hydrochloric acid. The molar concentration of tetraethyl orthosilicate in the precursor fluid A is 1.506 mol / L. The precursor solution B is formed by dissolving an aluminum source in ethanol and adding hydrochloric acid to prevent the aluminum source from precipitating. In the precursor solution B, the molar concentration of the aluminum source is 0.782 mol / L; the aluminum source is aluminum isopropoxide. The precursor solution C is formed by dissolving a boron source in ethanol, and the molar concentration of the boron source in the precursor solution C is 1.564 mol / L; the boron source is trimethyl borate. The precursor fluid D is formed by dissolving sodium nitrate, barium nitrate, calcium nitrate, cerium nitrate, and beryl acid in an ethanol solution, and the concentration of nitrate ions in the precursor fluid D is 1.05 mol / L; the molar concentration of cerium ions is 0.034 mol / L. The volume ratio of precursor body fluid B, precursor body fluid D, precursor body fluid C to precursor body fluid A is 1:3.85:2.5:5.8.

[0074] 2.2) Placement into mold: Take the precursor fluid and place it into the mold.

[0075] 2.3) Drying treatment: The mold containing the dry gel is placed in a vacuum drying oven and dried at a temperature of 40°C for 5 hours to obtain the dry gel, which has a thickness of 2 mm. 2.4) Heat treatment and sintering: The dry gel is first heated in a muffle furnace to remove residual ethanol and nitrate. Then the dry gel is transferred to a tube furnace and sintered in a vacuum environment and reducing atmosphere. Subsequently, it is cooled to room temperature in the tube furnace to obtain a glass substrate. The heating temperature in the muffle furnace is 250℃ and the heating time is 1.5h. The sintering temperature in the tube furnace is 440℃ and the sintering time is 3h.

[0076] 3) Laser processing: The laser processing system uses ultraviolet laser to process the glass substrate prepared in step 2) into an optical storage medium.

[0077] In step 3), the laser processing system includes an ultraviolet laser and, along the optical path of the ultraviolet laser emitted by the ultraviolet laser, an energy control module, a polarization control module, a reflector, an objective lens, and a three-dimensional displacement stage arranged sequentially. The energy control module is used to regulate the output energy of the ultraviolet laser, the polarization control module is used to regulate the polarization state of the near-ultraviolet laser, the reflector is used to reflect the ultraviolet laser to the objective lens, the three-dimensional displacement stage is used to support the glass substrate and adjust the processing area of ​​the glass substrate, and the objective lens is used to focus the ultraviolet laser onto the glass substrate.

[0078] Example 6 The method for reducing the laser processing threshold using cerium-doped glass includes the following steps: 1) Select a glass substrate, wherein the glass substrate is borosilicate glass, and the general formula of the borosilicate glass is: aSiO2-bB2O3-cNa2O-dAl2O3-eBaO-fCaO-xCe 3+Where a, b, c, d, e, f, and x are the mole fractions of each component, and a = 0.66, b = 0.15, c = 0.1, d = 0.03, e = 0.02, f = 0.02, and x = 0.02.

[0079] 2) Preparation of the glass substrate selected in step 1), as follows: 2.1) Preparation of precursor solution: Based on the selected glass substrate type, prepare a precursor solution containing a silicon source and a cerium source, wherein the precursor solution contains Ce. 3+ The precursor fluid is composed of precursor fluid A, precursor fluid B, precursor fluid C, and precursor D, and: The precursor fluid A is an acidic solution formed by dissolving tetraethyl orthosilicate in an ethanol solution and adjusting the pH value to pH=3 with hydrochloric acid. The molar concentration of tetraethyl orthosilicate in the precursor fluid A is 1.352 mol / L. The precursor solution B is formed by dissolving an aluminum source in ethanol and adding hydrochloric acid to prevent the aluminum source from precipitating. In the precursor solution B, the molar concentration of the aluminum source is 0.713 mol / L; the aluminum source is aluminum isopropoxide. The precursor solution C is formed by dissolving a boron source in ethanol, and the molar concentration of the boron source in the precursor solution C is 1.426 mol / L; the boron source is trimethyl borate. The precursor fluid D is formed by dissolving sodium nitrate, barium nitrate, calcium nitrate, cerium nitrate, and beryl acid in an ethanol solution, and the concentration of nitrate ions in the precursor fluid D is 1.2 mol / L; the molar concentration of cerium ions is 0.085 mol / L. The volume ratio of precursor body fluid B, precursor body fluid D, precursor body fluid C to precursor body fluid A is 1:4:2.5:5.8.

[0080] 2.2) Placement into mold: Take the precursor fluid and place it into the mold.

[0081] 2.3) Drying treatment: The mold containing the dry gel is placed in a vacuum drying oven and dried at a temperature of 50°C for 4 hours to obtain the dry gel, which has a thickness of 3 mm. 2.4) Heat treatment and sintering: The dry gel is first heated in a muffle furnace to remove residual ethanol and nitrate. Then the dry gel is transferred to a tube furnace and sintered in a vacuum environment and reducing atmosphere. Subsequently, it is cooled to room temperature in the tube furnace to obtain a glass substrate. The heating temperature in the muffle furnace is 300℃ and the heating time is 1h. The sintering temperature in the tube furnace is 480℃ and the sintering time is 2h.

[0082] 3) Laser processing: The laser processing system uses ultraviolet laser to process the glass substrate prepared in step 2) into an optical storage medium.

[0083] In step 3), the laser processing system includes an ultraviolet laser and, along the optical path of the ultraviolet laser emitted by the ultraviolet laser, an energy control module, a polarization control module, a reflector, an objective lens, and a three-dimensional displacement stage arranged sequentially. The energy control module is used to regulate the output energy of the ultraviolet laser, the polarization control module is used to regulate the polarization state of the near-ultraviolet laser, the reflector is used to reflect the ultraviolet laser to the objective lens, the three-dimensional displacement stage is used to support the glass substrate and adjust the processing area of ​​the glass substrate, and the objective lens is used to focus the ultraviolet laser onto the glass substrate.

[0084] Comparative Example 1 1) Select a glass substrate, wherein the glass substrate is quartz glass; the quartz glass does not contain Ce. 3+ .

[0085] 2) Laser processing: The laser processing system uses a near-infrared femtosecond laser to laser process the glass substrate selected in step 1) into an optical storage medium.

[0086] Comparative Example 2 1) The glass substrate is borosilicate glass, and the general formula of the borosilicate glass is: aSiO2-bB2O3-cNa2O-dAl2O3-eBaO-fCaO-xCe 3+ Where a, b, c, d, e, f, and x are the mole fractions of each component, and a = 0.68, b = 0.15, c = 0.1, d = 0.03, e = 0.02, and f = 0.02.

[0087] 2) Laser processing: The laser processing system uses a near-infrared femtosecond laser to laser process the glass substrate selected in step 1) into an optical storage medium.

[0088] The same laser processing system was used to perform laser processing on the glass substrates prepared in Examples 1-6 and Comparative Examples 1 and 2. The laser processing thresholds are shown in Tables 1 and 2.

[0089] Table 1. Laser processing thresholds for Examples 1-3 and Comparative Example 1

[0090] Table 2. Laser processing thresholds for Examples 4-6 and Comparative Example 2

[0091] As can be seen from Tables 1 and 2, when 0 < x ≤ 0.02, as Ce... 3+ As the molar fraction of ions gradually increases, the laser processing threshold gradually decreases for the following reasons: Ce 3+The electronic configuration of the ion is [Xe]4f¹, and its core optical characteristic is the existence of a broad-spectrum transition from the 4f ground state to the 5d excited state. The energy level difference of this transition is highly matched with the energy of laser photons, which can directly break the wide-bandgap absorption barrier of traditional glass.

[0092] For ultraviolet lasers, Ce 3+ Ions absorb single-photon directly: Ce 3+ The energy range corresponding to the 4f→5d transition energy level difference happens to cover the photon energy of ultraviolet lasers (e.g., ultraviolet photon energy is about 3eV~6eV, which is similar to Ce). 3+ (The 4f→5d transition energy level difference matching). At this point, a single ultraviolet laser photon can be electrocuted by Ce. 3+ Direct absorption allows 4f electrons to transition to the 5d excited state, eliminating the need for multiphoton absorption in traditional glass and resulting in an order-of-magnitude improvement in absorption efficiency.

[0093] For near-infrared femtosecond lasers, Ce 3+ Ions exhibit multiphoton absorption: The single photon energy of enhanced near-infrared femtosecond lasers is relatively low (e.g., the photon energy of 1030nm near-infrared light is approximately 1.2eV), making it impossible to directly cross the wide bandgap of traditional glass, but Ce... 3+ The 4f→5d transition can be achieved through multiphoton absorption; the high peak power of femtosecond lasers (high energy concentration within short pulses) can enable Ce... 3+ Simultaneously absorbing 2-3 near-infrared photons, the superimposed energy satisfies the 4f→5d transition requirement. Compared to traditional glass, which has no Ce... 3+ random multiphoton absorption at time, Ce 3+ The 4f→5d transition provides a directional energy level channel for multiphoton absorption, which greatly increases the absorption probability.

[0094] The absorption of laser energy depends on the Ce content within the glass substrate. 3+ Ions, when Ce 3+ When the mole fraction increases within a reasonable range (0 < x ≤ 0.02, to avoid aggregation), the Ce per unit volume... 3+ With the increase in the number of ions, during laser irradiation, photons interact with Ce. 3+ The probability of collision and absorption is significantly increased, and more photons are effectively absorbed at the same laser energy. 3+ After absorbing photons, the excited-state 5d electrons transfer energy to the glass substrate via nonradiative transitions, causing rapid local energy accumulation in the glass substrate. When Ce... 3+ As the mole fraction increases, this energy transfer pathway becomes denser, allowing for a rapid attainment of the energy threshold required for processing.

[0095] The high threshold of traditional glass stems from the inefficiency of multiphoton absorption. Extremely high laser power is required for multiple photons to act on a single electron simultaneously, and most of the laser energy is wasted because it is not absorbed.

[0096] Whether it's the direct single-photon absorption of ultraviolet lasers or the directional multiphoton absorption of near-infrared femtosecond lasers, their absorption efficiency is far higher than the random multiphoton absorption of traditional glass. With Ce... 3+ As the mole fraction increases, the contribution of this efficient absorption becomes increasingly significant. For the same processing effect, the required laser energy can be substantially reduced, as evidenced by the laser processing threshold increasing with Ce. 3+ It gradually decreases as the mole fraction increases.

[0097] When x reaches 0.02, the laser processing thresholds for both quartz glass and borosilicate glass drop to no more than 60% of the corresponding comparative values, fully demonstrating the effectiveness of Ce. 3+ The significant effect on reducing laser energy means that laser processing systems can use lower-power lasers, and excessive heat accumulation is avoided by reducing heat input at the source; moreover, this invention enables Ce to achieve its intended effect through precise control of the fabrication process. 3+ It can be uniformly dispersed in the glass substrate, and the laser energy is absorbed synchronously throughout the glass substrate, resulting in a smoother heat distribution and no significant thermal gradient differences, thus suppressing thermal damage at the microscopic level. The low energy input only adapts the glass substrate to the optical storage requirements and will not cause melting or deformation; the smooth heat distribution makes the thermal expansion and contraction of the glass substrate more uniform, without stress concentration, eliminating the possibility of microcracks; at the same time, the heat effect area is limited to the processing point, and the surrounding glass substrate is unaffected, resulting in no residual thermal stress after processing.

[0098] However, when x > 0.02, the repulsive force between ions is insufficient to resist the aggregation tendency, resulting in the formation of Ce particles with a size of nanometers. 3+ Aggregates, whose refractive indices differ significantly from those of the glass substrate, act as light scattering centers. When light passes through the glass substrate, some of it is scattered by the aggregates to non-target directions, reducing the effective light intensity transmitted through the glass, resulting in decreased transmittance. For optical storage media, scattering loss directly affects laser read / write accuracy. For example, when reading information, scattered light can interfere with the detection of the target signal. Therefore, if x > 0.02, even if the processing threshold can be further reduced, the attenuation of transmittance will directly prevent the optical storage medium from being read / written normally, thus rendering it useless. Therefore, a mole fraction of 0.02 is the critical balance point between low processing threshold and high optical transmittance, and also the upper limit of doping to ensure the performance of the optical storage medium.

[0099] In conclusion, x=0.02 is Ce 3+ The optimal choice for doping. From the perspective of processing threshold, 2 mol% Ce 3+It can achieve a laser processing threshold reduction of 40%~42.5% (quartz glass from 200nJ to 115nJ, borosilicate glass from 150nJ to 90nJ), which is sufficient to significantly reduce the dependence of laser processing systems on high-power lasers, and reduce equipment costs and energy consumption; from the perspective of transmittance, Ce less than 2 mol% 3+ By avoiding aggregation and broad-spectrum absorption, the high transmittance of the glass substrate can be maintained to meet the needs of optical storage read and write.

[0100] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for reducing the laser processing threshold using cerium-doped glass, characterized in that, It includes the following steps: 1) Select a glass substrate, which is quartz glass or borosilicate glass; 2) Prepare the glass substrate selected in step 1) as follows: 2.1) Preparation of precursor solution: Based on the selected glass substrate type, prepare a precursor solution containing a silicon source and a cerium source, wherein the precursor solution contains Ce. 3+ ; 2.2) Mold filling: Place the precursor solution into the mold; 2.3) Drying treatment: Place the mold containing the precursor in a vacuum drying oven for drying to obtain a dry gel; 2.4) Heat treatment and sintering: First, place the dry gel in a muffle furnace for heating to remove residual ethanol and nitrate radicals, then transfer the dry gel to a tube furnace and sinter it under vacuum environment and reducing atmosphere conditions in the tube furnace, and then cool it to room temperature in the tube furnace with the furnace, thereby obtaining the glass substrate; 3) Laser processing: The laser processing system emits laser light to process the glass substrate prepared in step 2) into an optical storage medium.

2. The method for reducing the laser processing threshold using cerium-doped glass according to claim 1, characterized in that, In step 1), the glass substrate is quartz glass, and the general formula of the quartz glass is aSiO2-xCe. 3+ ; Where a and x are the corresponding molar fractions of each component, 0.98 ≤ a < 1, 0 < x ≤ 0.02, and a + x = 1.

3. The method for reducing the laser processing threshold using cerium-doped glass according to claim 1, characterized in that, In step 2. (1), the silicon source is tetraethyl orthosilicate, and the precursor solution is composed of precursor solution I and precursor solution II; The precursor solution I is an acidic solution formed by dissolving tetraethyl orthosilicate in ethanol and adjusting the pH value to pH = 2 - 3 with hydrochloric acid, and in the precursor solution I, the molar concentration of tetraethyl orthosilicate is 1 mol / L - 2 mol / L; The precursor solution II is a solution formed by dissolving cerium nitrate and oxalic acid in deionized water, and in the precursor solution II, the molar concentration of cerium ions is 0.1 mol / L - 0.136 mol / L; The volume V of the precursor fluid II Ⅱ The volume V of the precursor fluid I Ⅰ The ratio is: V Ⅱ / V Ⅰ ≤0.

15.

4. The method for reducing the laser processing threshold using cerium-doped glass according to claim 3, characterized in that, In step 2.4), the heating temperature in the muffle furnace is 420°C - 480°C, the heating time is 1 h - 2 h, the sintering temperature in the tube furnace is 1800°C - 1900°C, and the sintering time is 2 h - 4 h.

5. The method for reducing the laser processing threshold using cerium-doped glass according to claim 1, characterized in that, The glass substrate is borosilicate glass, and the general formula of the borosilicate glass is: aSiO2-bB2O3-cNa2O-dAl2O3-eBaO-fCaO-xCe 3+ ; Where a, b, c, d, e, f, x are the corresponding molar fractions of each component, and 0.6 < a < 0.8, 0.1 < b < 0.2, 0.05 < c < 0.15, 0.01 < d < 0.05, 0.005 < e < 0.05, 0.00 < f < 0.05, 0 < x ≤ 0.02, and a + b + c + d + e + f + x = 1.

6. The method for reducing the laser processing threshold using cerium-doped glass according to claim 1, characterized in that, In step 2.1), the precursor solution is composed of precursor solution A, precursor solution B, precursor solution C, and precursor D, and: The precursor solution A is an acidic solution formed by dissolving tetraethyl orthosilicate in an ethanol solution and adjusting the pH value to pH = 2 - 3 with hydrochloric acid. In the precursor solution A, the molar concentration of tetraethyl orthosilicate is 1.352 mol / L - 1.672 mol / L; The precursor solution B is formed by dissolving an aluminum source in ethanol and adding hydrochloric acid to prevent the precipitation of the aluminum source. In the precursor solution B, the molar concentration of the aluminum source is 0.713 mol / L - 0.875 mol / L; The precursor solution C is formed by dissolving a boron source in ethanol, and in the precursor solution C, the molar concentration of the boron source is 1.426 mol / L - 1.713 mol / L; The precursor solution D is formed by dissolving sodium nitrate, barium nitrate, calcium nitrate, cerium nitrate and beryl acid in an ethanol solution, and the concentration of nitrate ions in the precursor solution D is 0.9 mol / L to 1.2 mol / L; the molar concentration of cerium ions is not greater than 0.085 mol / L. The volume ratio of precursor body fluid B, precursor body fluid D, precursor body fluid C to precursor body fluid A is 1:(3.7~4):2.5:5.

8.

7. The method for reducing the laser processing threshold using cerium-doped glass according to claim 6, characterized in that, In step 2.4), the heating temperature in the muffle furnace is 200℃~300℃ and the heating time is 1h~2h, while the sintering temperature in the tube furnace is 400℃~480℃ and the sintering time is 2h~4h.

8. The method for reducing the laser processing threshold using cerium-doped glass according to claim 1, characterized in that, In step 2.3), the thickness of the dry gel is 2mm to 3mm.

9. The method for reducing the laser processing threshold using cerium-doped glass according to claim 1, characterized in that, In step 2.3), the vacuum drying temperature is 35℃~50℃, and the vacuum drying time is 4h~6h.

10. The method for reducing the laser processing threshold using cerium-doped glass according to claim 1, characterized in that, In step 3), the laser processing system includes a laser and, sequentially arranged along the optical path of the laser emitted by the laser, an energy control module, a polarization control module, a reflector, an objective lens, and a three-dimensional displacement stage. The energy control module is used to regulate the output energy of the laser, the polarization control module is used to regulate the polarization state of the laser, the reflector is used to reflect the laser to the objective lens, the three-dimensional displacement stage is used to support the glass substrate and adjust the processing area of ​​the glass substrate, and the objective lens is used to focus the laser onto the glass substrate.

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