Why is blue laser beam shaping challenging? How to innovate and make breakthroughs?

Semiconductor Review | Friday, October 27, 2023

Joanna Qiao

Single (A)cylindrical Lenses Product Line Director of Laser Optics Business Unit, Focuslight

Stay ahead of the industry with exclusive feature stories on the top companies, expert insights and the latest news delivered straight to your inbox. Subscribe today.

Leon Li

Vice President of Automotive BU, Vice President of Business and Strategy of Laser Optics Business Unit, Focuslight

In recent years, the utilization of blue diode lasers has undergone a remarkable expansion. Compared with near-infrared lasers (750~1100 nm), a blue laser with a wavelength in the 400~500 nm has a much higher (5x – 10x) absorption of highly reflective metals such as copper. The blue laser has become the ideal light source for high-reflective metal processing, offering substantial advantages in various industrial applications such as cutting and welding. Furthermore, in the context of the global drive for energy saving and environmental protection, blue lasers have found a prominent role in numerous emerging energy sectors. For instance, they are now integral in the production and manufacturing of electric vehicles, lithium batteries, photovoltaic systems, and wind energy equipment, where high-reflective metals such as copper are widely employed. These new applications have opened up a broad market for blue laser technology.

As the power of blue lasers gradually increases and the cost decreases, along with the emergence of more application scenarios, the market demand for blue lasers is unprecedentedly high. In novel applications such as blue laser engraving, medical care, display, and lighting, blue laser is drawing considerable attention from the market.

In the field of engraving and cutting, blue laser engraving devices can engrave patterns on metal, food, wood, plastic, and other materials, offering cost-effective solutions that cater to both commercial and household applications. In medical applications, blue laser surgical equipment can be used for prostate hyperplasia treatment, and its lower-power version can be used for the treatment of ear, nose, throat and digestive tract diseases. Blue laser 3D printing can be used for the production of human prostheses. The blue laser also has significant advantages in laser display applications like wide color space and long life, environmental protection, energy saving, etc., achieving the ultimate display effect, color, and clarity. In laser lighting applications, the laser lighting sources use blue laser to excite phosphors to produce white light, which can achieve higher power density and farther illumination distance and can be used in laser headlights, remote search, and many other fields.

1. Challenges in Beam Shaping of Blue Diode Lasers

Similar to near-infrared diode lasers, blue diode lasers also need to be matched with a suitable beam shaping solution in order to efficiently utilize the photon energy they emit. As an emerging field, blue laser beam shaping faces new challenges in beam shaping compared with infrared laser beam shaping:

🔹The absorption rate of commonly used optical materials in the blue spectrum is higher than that in the near-infrared spectrum. Excessive absorption of laser light by materials will increase the temperature rise of optical components, causing changes in the size of optical components, thereby affecting the product performance. At the same time, the temperature rise of optical components may influence the performance and reliability of the glue that fixes the optical components, thereby affecting the optical performance and reliability of the blue laser system;

🔹Blue optics’ design needs to take into account the diverse application scenarios and packaging forms of blue lasers;

🔹There are new challenges in the coating of blue light optical components.

Depending on the applications, different beam shaping methods need to be used to meet the application's demand for photon energy.

2. Beam Shaping Solution for Blue Diode Laser

To formulate suitable beam shaping solutions for blue lasers, three aspects need to be considered: selection of optical materials, micro-optical design, and optical coating design.

a. Selection of optical materials

When selecting optical component materials for blue diode laser applications, in addition to considering parameters such as hardness and refractive index, special consideration needs to be given to the challenges posed by transmittance in the blue spectrum. Common microlens glass materials (such as S-TIH53, etc.) have good transmittance (>99.5%) for the near-infrared spectrum but have low transmittance for the blue spectrum (75%~95% for S-TIH53) and higher absorption. Excessive absorptivity can cause temperature rise and thermal lens effect, resulting in changes in the size of the microlens product, thereby affecting the optical performance of the product; the temperature rise of the micro-optical lens may also affect the performance of the glue and reduce the reliability of the system.

Fused silica is an ideal raw material for blue optics components. Its high transmittance (>99.5%) in the blue spectrum makes it naturally suitable for high-power blue laser applications. However, the conversion temperature of fused silica can reach 1600 degrees, which is not suitable for thermal molding or other optical processing techniques that are commonly used for aspherical lenses. Focuslight's innovative wafer-level simultaneous structuring process offers solutions to this challenge. This technique eliminates the need for heating and melting fused silica during processing. Over time, it has evolved into a mature method extensively applied in the mass production of fused silica micro-optical components. Its adoption has been widespread in recent years across various fields, including the beam shaping of infrared semiconductor lasers and UV homogenizers for photolithography machines.

On the other hand, the refractive index of fused silica is about 1.46, lower than common optical materials with a refractive index of 1.8 such as S-TIH53. This variance imposes constraints on optical design. Although optical designs such as biconvex lenses can be considered for refractive index compensation, this will significantly increase the cost and is not an ideal choice for situations where high refractive index is required. Focuslight’s wafer-level simultaneous structuring process can be used to process almost any non-toxic optical glass, including materials such as calcium fluoride, magnesium fluoride, and even silicon and germanium suitable for infrared and deep ultraviolet applications. Therefore, after two years of dedicated R&D and exploration, Focuslight has successfully developed and introduced a new material (designated as FL-Blue) that is adapted to the wafer-level simultaneous structuring process, demonstrating low absorption in the blue spectrum (transmittance >99%) and a high refractive index (n >1.7). Based on this material, Focuslight has released Blue FAC 250, Blue FAC 300, Blue FAC 380, and Blue FAC 600 series fast axis collimator (FAC) products. Additionally, small batches of blue optical components have been delivered to leading blue laser customers worldwide.

b. Micro-optical design

With the right optical materials in place, it's equally important to employ fitting optical designs that can accommodate the diverse application scenarios of blue lasers.

Blue diode lasers usually come in different forms such as CoS packaged single emitters, TO-can packaged single emitters, and chip arrays (bars). For different light source forms and different application scenarios, targeted designs are required to meet application needs.

At Focuslight, various micro-optical surface structures, such as aspherical cylinders, parabolas, free-form surfaces, and other surface structures can be realized using wafer-level simultaneous structuring process. Through high-precision processing of double-sided micro-optics, the integration of multiple lenses can also be achieved on micro-sized optical products.

When doing optical design, it is also necessary to consider the refraction and diffraction effects of light at the same time. Focuslight uses ray tracing algorithms and wave optics theory to conduct optical simulations, and also uses self-developed wave optics simulation software to fully simulate the diffraction effect.

Focuslight has designed and released multiple high-performance blue laser optical component products based on different materials such as FL Blue and fused silica, such as blue fast axis collimators (FACs), blue meniscus slow axis collimators (SACs), monolithic collimators, monolithic fiber couplers, fused silica lens arrays, and fused silica beam transformation systems (BTS).

c. Optical coating design

Once materials are selected and optical designs finalized, blue laser optical components undergo crucial optical coating. With over 20 years of expertise, Focuslight's team employs advanced film design and characterization techniques for complex and challenging settings, ensuring cost-effective large-scale coating production. Its coating solutions cover various types such as anti-reflection coating, high-reflection coating, ultra-low-reflection coating, filtering, and beam splitting. Customized coatings can be developed for customers based on the application requirements of different products. Focuslight also conducts tests of laser damage threshold, weak absorption, temperature rise, and environmental reliability to ensure stable, consistent performance during long-term use and mass production.

Focuslight provides a range of high-performance, high-reliability optical components for blue beam shaping. With 30 years of beam shaping excellence in micro-optical design and manufacturing, Focuslight offers precise control over photon manipulation, achieving optimal results for various applications. This expertise allows for precise photon control, ensuring ideal outcomes across diverse applications. Focuslight’s world’s leading wafer-level simultaneous structuring technology produces polished wafers up to 300 x 300 mm², offering a scalable and cost-effective solution for high-volume production, with a monthly capacity over 3 million pieces.

More in News

The pursuit of absolute purity in semiconductor manufacturing presents significant challenges, as even a single microscopic particle can jeopardize the integrity of an entire production batch. As integrated circuits continue to shrink to the atomic level, the performance specifications governing the packaging and transportation of aggressive chemicals used in etching and cleaning processes have become increasingly stringent. Advanced fluororesins have emerged as fundamental components of this infrastructure, offering exceptional thermal stability and chemical inertness, attributes unmatched by any alternative materials. These application-specific polymers establish a protective barrier against contamination, thereby facilitating global fabrication facilities in their efforts to achieve higher yield objectives. When integrated into the production line, these high-performance materials provide manufacturers with a competitive advantage characterized by enhanced reliability and long-term structural integrity. How Does Chemical Inertness Drive Process Stability? The main advantage of fluororesins in semiconductor applications is their resistance to almost all corrosive materials used in wafer processing. Strong acids and organic solvents can corrode regular piping and storage systems, thus releasing metallic ions or particulates into the process stream. Under such conditions, fluororesins do not react, thereby preserving the ultra-high purity required for the processing of advanced logic and memory chips. This stability directly translates into reduced downtime for equipment maintenance and a corresponding reduction in the risk of unforeseen system breakdowns. Diversified Technologies, Inc. implements comparable high-purity and contamination-control measures in semiconductor systems to ensure consistent operational reliability. Due to their low surface energy, these materials reduce residue buildup and facilitate easier drainage, thus providing the shortest possible interruption for tools returning to production between flushes. As production facilities continue to improve their resource consumption, the long lifetimes of fluororesin parts open a straightforward approach to sustainable operational efficiency and lower total cost of ownership throughout the equipment lifecycle. DEMCO provides industrial-grade components and materials designed to maintain process integrity and minimize downtime in advanced semiconductor manufacturing. Why Is Thermal Resilience Crucial For Scaling? As the industry moves toward more complex three-dimensional architectures, the thermal loads on components being manufactured are increasing. Fluororesins would retain their mechanical properties over a wide temperature range, which is necessary in setups with very rapid thermal cycling or chemicals washed at high temperatures. Their thermal resilience ensures that seals, gaskets, and linings will not deform or lose their sealing properties in response to heat, thereby maintaining vacuum integrity in the processing chamber. It is precisely this ability to withstand changes without structural damage or outgassing that allows engineers to push the current limits of fabrication. In addressing material selection from a strategic viewpoint, business leaders must acknowledge that the physical limitations of the manufacturing environment are often equilibrated by the materials that constitute the containment of the process. The investment in advanced fluororesin solutions provides organizations' technical teams with opportunities to explore the cutting edge of microelectronics. This convergence of material science and industrial strategy will ensure that the infrastructure of the digital economy remains robust and poised to meet the next generation of consumer and enterprise demand for processing power. ...Read more
The proliferation of the Internet of Things (IoT) and advanced embedded systems is fundamentally reshaping the digital landscape. From smart cities and connected vehicles to industrial automation and intelligent medical devices, these innovations are driving an unprecedented demand for localized intelligence and real-time processing. At the heart of this revolution lie semiconductors, the unsung heroes powering the "edge" – where data is generated and acted upon, rather than solely relying on distant cloud infrastructure. The Semiconductor Imperative: Core Requirements for the Edge To meet the demanding requirements of next-generation IoT and embedded systems, semiconductors are evolving rapidly, with a strong focus on key performance attributes. Foremost is low power consumption, as many IoT devices operate on batteries in environments where frequent recharging or replacement is not feasible. This necessitates ultra-low-power architectures, efficient RF and physical layer designs, and optimized deep-sleep modes. Innovations such as voltage and frequency scaling (DVFS) and smart memory integration play a critical role in extending battery life. The shift toward processing complex AI and machine learning tasks at the edge has also increased the need for high-performance, energy-efficient computing. To this end, specialized processors—including AI accelerators and Neural Processing Units (NPUs)—are being integrated to enable real-time inference with minimal power usage. Miniaturization and functional integration are also vital, as IoT devices are often constrained by size and cost. Advances in semiconductor design now enable the consolidation of processing, memory, connectivity, and security functions into a single System-on-Chip (SoC), thereby improving efficiency across the board. Equally important is robust security. As IoT devices become more widespread, they are increasingly vulnerable to cyber threats. Semiconductor designs are therefore incorporating hardware-level security features such as secure boot, hardware root of trust, encryption for secure communication, secure key management, and tamper detection mechanisms. Innovations Driving the Future of Edge Semiconductors The semiconductor industry is experiencing a surge of innovation aimed at meeting the demands of next-generation computing. One significant development is the emergence of edge AI chips—dedicated processors designed to perform inference directly on devices. These chips are optimized for applications such as surveillance, industrial robotics, and smart home systems, with a focus on power efficiency, low latency, and compact form factors. Likewise, chiplet architectures are gaining prominence, replacing traditional monolithic designs with modular components that enhance scalability, enable efficient power management, and support heterogeneous integration within a single package. Advancements in process technologies are also driving progress, with leading-edge fabrication techniques like FinFET and Gate-All-Around (GAA) transistors improving energy efficiency by reducing power leakage and lowering operating voltages. Meanwhile, the adoption of the open-source RISC-V instruction set architecture is expanding across embedded systems. Its flexibility and cost-effectiveness enable greater customization, thereby accelerating innovation in chip design. Another transformative area is neuromorphic computing, which mimics the architecture of the human brain to deliver ultra-low-power, high-performance AI processing. This approach holds particular promise for real-time analytics and adaptive, self-learning embedded systems. The symbiotic relationship between semiconductors and edge computing will continue to drive innovation. As the IoT expands exponentially, the demand for more intelligent, secure, and energy-efficient edge devices will only grow. The future of embedded systems and IoT will be defined by semiconductor advancements that enable faster processing, robust security, longer battery life, and seamless connectivity, truly empowering the edge to become a strong, distributed intelligence network. ...Read more
Executives acquiring quartzware fabrication systems face a purchasing decision that reaches beyond component replacement. In semiconductor and adjacent manufacturing environments, quartzware sits close to process performance, equipment uptime and yield protection. A tank, carrier, tube, chamber or heat exchanger that appears minor on a procurement list can become a constraint when purity, tolerance control or lead time fails to match production needs. The right fabrication partner must therefore be assessed not only by what it can build, but by how consistently it can support continuity when demand shifts, equipment ages or legacy parts become difficult to source. Current pressure on manufacturing teams has made this decision more exacting. Many facilities are trying to extend asset life while maintaining process discipline, controlling cost and avoiding downtime. New builds remain necessary, but replacement alone is not always the rational answer. When a damaged quartz component can be restored to specification, repair capability becomes a strategic purchasing advantage. It helps teams preserve scarce capital, shorten recovery windows and reduce dependence on fresh fabrication when production schedules are exposed to raw material and capacity delays. Precision is still the baseline. Quartzware used in semiconductor equipment must be fabricated from appropriate high-purity material and held to tight dimensional requirements because contamination and variation can travel quickly into yield loss. Buyers should look for evidence that the supplier treats quality control as a release discipline rather than a final formality. That means documented inspection, tolerance verification, equipment upkeep and a workforce trained to repeat complex work without relying only on individual memory. A supplier’s ability to keep machinery calibrated, maintain fixtures and invest in the people doing the work often determines whether quality holds steady beyond one successful order. Flexibility is equally important. Many manufacturers inherit tools, assemblies and parts without current drawings, especially when equipment has been modified, transferred or supported by older OEM documentation. A capable quartzware fabrication system should be able to reverse engineer unfamiliar parts, translate samples into workable drawings and support both one-off and recurring needs. This is where the distinction between a parts vendor and a true fabrication resource becomes clear. The stronger partner can handle unusual geometries, repairs, production pieces and urgent requests while preserving inspection discipline and delivery reliability. Delivery performance should be treated as a technical requirement, not a customer service promise. In fabricationdependent manufacturing, lateness does not merely inconvenience purchasing. It can idle equipment, delay qualification or force teams into lower-quality substitutes. Strong suppliers build reliability through planned maintenance, trained labor, transparent quoting and realistic commitments. The best choice is the partner that can combine purity, repair judgment, engineering adaptability and delivery consistency into one dependable source. Desert Glass Works stands out for buyers needing this balance. Its relevant work spans quartzware repair, custom machining and precision fabrication for tanks, carriers, process chambers, diffusion tubes, bell jars, heat exchangers and related semiconductor components. The company’s model is well matched to buyers managing new requirements and legacy equipment, since it can repair or restore parts, reverse engineer components without drawings and fabricate custom quartzware from high-purity stock. Its emphasis on full inspection, maintained equipment, apprenticeship-based skill development and on-time delivery makes it a strong recommendation for organizations that need quartzware support tied directly to yield, uptime and disciplined execution. ...Read more
Longer validation cycles are forcing semiconductor factories to examine a cost that rarely appears cleanly on a procurement sheet: the time lost among test readiness, tool availability, engineering bandwidth and material movement. Advanced packaging, AI processors, automotive electronics and mixed-signal devices have widened the range of qualification work inside the same facility. A test cell may be technically capable, yet throughput still suffers when device programs shift faster than handlers and factory logistics can adjust. That pressure often shows up as idle equipment rather than an obvious planning failure. The buying question is no longer confined to tester performance. Executives responsible for semiconductor test and robotics systems need to understand how a platform behaves when product mix changes and validation data expands while factory movement becomes a constraint on output. Hardware flexibility matters because qualification programs cannot wait for major reconfiguration every time a device family changes. The test environment should support wafer sort, final test, system-level validation and diagnostic review while allowing engineering teams to move between device requirements with limited disruption.  Diagnostic visibility carries equal weight. AI accelerators and dense system-on-chip designs produce large volumes of validation data under demanding electrical conditions. Engineers need earlier anomaly detection, clearer failure analysis, yield-behavior context  and a practical way to connect test results to process variation. A system that only records pass-fail results leaves too much interpretation for later review. Better infrastructure helps teams identify variation while the qualification window is still open. Factory movement has become part of the same purchase logic. Semiconductor facilities often lose time in the handoff between test stages, especially when materials or qualified components depend on manual transport. Robotics should reduce that drag without forcing the factory into a redesign. Collaborative robots must be practical for inspection and machine tending, while autonomous mobile robots should coordinate transport across existing floor layouts, adjust to changing routes, respond to obstacles and reduce waiting time around qualification flow. Integration is where many automation programs lose momentum. Test equipment, robotics systems, factory software and data tools frequently come from different vendors, making communication gaps a real production issue. Buyers should press for open integration and clear status data. Deployment paths also matter, especially when custom work stretches past the point of early value. Reliability remains nonnegotiable, since a robot or tester that adds downtime during a qualification push creates the problem it was purchased to solve. Teradyne fits this buying logic because it brings semiconductor test equipment and intelligent robotics into one portfolio relevant to validation and factory flow. Its test systems support wafer sort, final test, system-level validation and broader device qualification for memory, analog, mixed-signal and system-onchip applications. Universal Robots gives it collaborative robots suited to machine tending and inspection work. Mobile Industrial Robots supports autonomous transport inside manufacturing environments. Teradyne’s emphasis on analytics, adaptable test platforms, collaborative automation and mobile robotics gives semiconductor executives a practical route to connect validation accuracy with steadier factory coordination. For buyers trying to reduce qualification delays without separating test decisions from movement constraints, it deserves close evaluation. ...Read more