General Overview Lumentum Holdings Inc. (“we,” “us,” “our”, “Lumentum” or the “Company”) is a global leader in optical and photonic technologies and an industry-leading provider of optical and photonic products based on revenue and market share. Our products are essential to a range of cloud, artificial intelligence and machine learning (“AI/ML”), telecommunications, consumer, and industrial end-market applications. We operate in one reportable segment as a single, integrated enterprise. See “Note 17. Operating Segments and Geographic Information” to the consolidated financial statements. We disaggregate revenue by type of product, which are Components and Systems, and by geography. A Components product is defined as one of the individual building blocks that goes into creating a larger solution. It is typically not a complete solution on its own but rather a specialized element that enables system functionality. This includes semiconductor laser chips, laser sub-assemblies, line subsystems and wavelength management systems. These are supplied to customers who then integrate them into their own full system solutions. Components represent foundational parts that support or enable that system’s operation and include optical chips and subsystems that are supplied to cloud data center operators, AI/ML infrastructure providers, and network equipment manufacturer customers. A Systems product is defined as a complete, stand-alone solution that delivers full functionality to the end customer. It is typically self-contained and ready to operate within a customer’s network or application environment. This includes optical modules, optical circuit switches, and industrial lasers such as short-pulse solid-state lasers and kilowatt-class fiber lasers. These products integrate multiple technologies and subsystems into a finished solution that directly addresses a customer’s needs. A system represents the end-product that can be deployed and used independently. Our products enable high-capacity optical links for cloud computing, AI/ML workloads, and data center interconnect (“DCI”) applications, as well as for communications service provider networks. Our offerings support access (local), metro (intracity), long-haul (intercity and global), and submarine (undersea) network infrastructure. Our products serve enterprise network infrastructure needs, including storage area networks (“SANs”), local area networks (“LANs”), and wide area networks (“WANs”). Demand for our products is fueled by the ongoing expansion of network capacity required to support cloud services, AI/ML processing, streaming video, video conferencing, wireless and mobile connectivity, and the internet of things (“IoT”). In addition, our industrial laser products are used for precision material processing across diverse industries, including semiconductor and microelectronics fabrication, electric vehicle and battery production, metal cutting and welding, and advanced manufacturing that emphasize greater manufacturing precision, flexibility, and sustainability. 2 Table of Contents We have a global footprint that enables us to address global market opportunities for our products with employees engaged in research and development (“R&D”), administration, manufacturing, support and sales and marketing activities in various locations worldwide. Our headquarters are located in San Jose, California, and we have manufacturing capabilities and facilities in North America, Asia-Pacific, and Europe. Lumentum was incorporated in Delaware as a wholly owned subsidiary of JDS Uniphase Corporation (“JDSU”) on February 10, 2015. In August 2015, we were spun off from JDSU and became an independent publicly traded company through the distribution of our common stock by JDSU to its stockholders. Since our spin-off from JDSU (now Viavi Solutions, Inc., or Viavi), we have completed a number of acquisitions, including Oclaro, Inc. (“Oclaro”) in 2018, NeoPhotonics Corporation and IPG Photonics’ telecom transmission product lines in 2022, and Cloud Light Technology Limited (“Cloud Light”) in 2023. These acquisitions have enhanced our product portfolio, broadened our revenue mix and strengthened our position to meet the evolving needs of our customers. Our Industry Our business is driven by end-market applications leveraging the performance advantages of advanced optical and photonic solutions. We operate within global markets characterized by robust, long-term growth trends that are increasing demand for our products and technologies. The convergence of factors including the growing reliance on data transmission, the rapid adoption of AI/ML, and the increasing digitalization of society is driving expansion in cloud data centers and the demand for higher-bandwidth network solutions. Our products and technologies are at the forefront of these trends, engineered to support increased data volumes and computational loads while meeting the industry's need for advanced network capabilities. Additionally, the manufacturing industry's pursuit of higher precision, innovative materials, and improved efficiency fuels demand for industrial laser-based solutions. Lumentum is well-positioned to capitalize on this trend through the provision of ultrafast lasers for micromachining and advanced material processing. In addition, we also produce laser emitters for 3D sensing applications in consumer electronics. While we maintain a positive outlook on the long-term prospects for our products and technologies, we acknowledge the presence of industry and market risks and uncertainties, including fluctuations in supply and demand, that have led to volatility in our business and financial performance. Industry Conditions Through fiscal year 2024, we experienced significant fluctuations in demand as customers delayed projected shipments or built up inventory in response to supply shortages and then brought down inventories as supply chain constraints eased. Our revenue fluctuated in response to these changes in demand and our margins were adversely impacted as we were not able to fully recover costs, such as underutilized manufacturing capacity. However, beginning in the first quarter of fiscal year 2025, network equipment manufacturers normalized inventory levels; and since then, we have seen increasing demand from AI and cloud customers as they continue to expand their data centers, driven in part by the continued advances in cloud and AI infrastructure. This demand is outpacing our current supply which has required us to make decisions on supply allocation. We are investing in manufacturing capacity, both internally and with contract manufacturers, to meet demand. Our supply chain is complex, and we need to manage supply of certain components required to build our products while confronted with fluctuating demand from our customers. From time to time, we experience logistics and supply chain issues and shortages of the types of components we and our customers require in our products, and when we experience these shortages, we have had to incur incremental supply and procurement costs in order to increase our ability to fulfill demands from our customers. Due to worldwide operations, we and our customers are also subject to risks relating to the global trade environment. We are actively monitoring and assessing the global trade environment, particularly with respect to various proposed and enacted changes in tariff regulations and trade restrictions. The ongoing uncertainty surrounding trading policies, including the potential for additional tariffs, restrictions related to our customers and retaliatory measures by non-U.S. governments, continues to create a volatile environment that could disrupt our operations. The imposition of tariffs on certain imported goods and materials and export controls on critical components may increase our costs and place upward pressure on the cost of goods sold, which, in turn, may reduce our gross margins if we are unable to pass these costs onto customers through price increases. For more information on risks associated with supply chain constraints and customer inventory, as well as tariffs and other trade restrictions, refer to Item 1A “Risk Factors” of this Annual Report. 3 Table of Contents Geopolitical Developments As a global business with operations spanning diverse geographic regions, we are exposed to geopolitical risks. Fluctuations in the geopolitical landscape, including war, military conflicts, changes in export regulations, the effects of heightened, scheduled, or proposed tariffs, and shifts in national priorities and foreign relations policies, can significantly impact our business. For instance, modifications to trade restrictions and export regulations can adversely affect both product demand and our ability to supply customers, which would harm revenue and profit margins. Moreover, disruptions in our customers' supply chains due to geopolitical events could reduce or delay their demand for our products, ultimately impacting our revenue and operating results. For more information on risks associated with the change in geopolitical landscape and regulatory actions, refer to Item 1A “Risk Factors” of this Annual Report. Markets We maintain leading market positions in our fast-growing optical networking markets through our extensive product and technology portfolio and close relationships with a wide range of market-leading customers. We provide a wide range of optical and photonic components, modules, and subsystems that support high-speed, high-capacity transmission of data over fiber optic links in cloud data centers, AI/ML, enterprise and communications services networking. Our customers include cloud and network service providers, AI infrastructure providers, and network equipment manufacturers (“NEMs”). Within data center and AI/M applications, our products enable high-speed interconnection across networked servers, AI accelerators, storage, and switches. Within communication service provider applications, our products support high-capacity access (local), metro (intracity), long-haul (city-to-city and worldwide) and submarine (undersea) optical networks. Within the industrial market, our diode lasers serve as pump sources for high-power fiber lasers used in metal fabrication and other demanding applications. Our ultrafast lasers cater to industries such as printed circuit board manufacturing, semiconductor processing, electric vehicle battery production, solar cell production, and flat panel display fabrication, where precise micromachining is essential. In the consumer electronics market, our laser light sources are integral components of 3D sensing cameras used in smartphones, computers, and other consumer electronics devices. These 3D sensing capabilities enable applications such as biometric identification, augmented and virtual reality, and computational photography. Trends The convergence of cloud computing and AI is driving rapid innovation and expansion in optical hardware for hyperscale operators. The immense computational demands of training and running AI models are shifting infrastructure from traditional copper interconnects to high-speed photonics. Concurrently, surging data traffic from video streaming, search engines, e-commerce, and cloud services continues to fuel the data center expansion. Photonic solutions offer substantial advantages over copper connections, including ultra-fast, high-volume data transmission and reduced electromagnetic interference, enabling data traffic to continue to scale to accelerate AI model training and enhance high-performance computing (“HPC”) efficiency. To address these challenges, web-scale companies are adopting distinct optical architectures: •Scale-Out Optical Solutions: Optical hardware connects individual compute clusters, servers, and switches across the broader data center network to manage massive parallel workloads. This includes the adoption of 200G lane speed optical components that double data transfer rates compared to traditional 100G lanes. •Scale-Up Optical Solutions: High-speed photonics and optical switches are deployed to directly cluster and interconnect GPUs and AI accelerators within the compute fabric, maximizing cluster efficiency and processing speeds. •Scale-Across DCI Solutions: High-speed data center interconnects (“DCIs”) are constructed to enable seamless, low-latency data exchange across geographically dispersed data center units. This scale-across capability optimizes resource utilization by allowing cloud operators to leverage and balance computing power across multiple disparate locations. The exponential growth of data across industries also drives the expansion of long-haul, metro, and access networks. Dense wavelength-division multiplexing (“DWDM”) technologies are being leveraged to increase data speeds while reducing costs. High-end networking equipment must now handle both legacy and internet protocol traffic while meeting stringent requirements for bandwidth, scalability, speed, reliability, compactness, and cost-effectiveness. 4 Table of Contents Further, the dynamic nature of network traffic demands agile optical networks that adapt to changing conditions. Technologies like Reconfigurable Optical Add-Drop Multiplexers (“ROADMs”), wavelength-selective switches, and tunable transmission products facilitate remote capacity adjustments. This need for capacity expansion across DCIs, metro regional networks, and long-haul networks is further accelerated by the widespread deployment of 5G mobile networks and bandwidth-intensive applications is increasing data speed at the network edge. The industrial laser market is driven by the pursuit of precision and efficiency in material processing. Fiber lasers have surpassed gas lasers in sheet metal processing and welding due to their superior power, beam quality, power efficiency, and cost-effectiveness. This technology empowers manufacturers across metal fabrication, automotive, and electronics to produce smaller, lighter, and more functional products from advanced materials. The trend toward miniaturization necessitates precise micromachining with minimal heat impact. Solid-state and ultrafast lasers excel in these tasks, replacing traditional tools for processes like creating vias in circuit boards and singulating wafers. Ultrafast lasers, with their exceptionally short pulses, are particularly adept at the delicate and precise micromachining required in semiconductor, display, solar cell, and EV battery production. In the consumer market, laser light sources are integral to 3D sensors primarily used in mobile devices. This technology enables real-time depth perception, transforming image capture and granting devices the ability to perceive the world in three dimensions. Applications span biometric identification, computational photography, virtual and augmented reality, and natural user interfaces. Offerings Lumentum is a leading provider of high-speed optical transceivers and optical components underpinning modern AI and cloud computing applications. Optical transceivers and data interconnect solutions are essential for connecting servers, switches, and routers within data centers. We also manufacture key components used in optical transceivers and data interconnect solutions, including high-speed laser transmitters, photonic integrated circuits, and photodiodes, high-power laser light sources. For data center interconnects, Lumentum offers both its own coherent pluggable transceivers and the underlying ultra-narrow linewidth laser and coherent components used by transceiver customers. Beyond standard offerings, we deliver customized solutions tailored to specific customer needs, such as high-power laser sources, compact laser arrays, and advanced packaging schemes enabling co-packaged optics and integrated photonics assemblies. In metro and long-haul optical networks, Lumentum offers a comprehensive suite of coherent and direct-detect optical transmission components, modules, and optical transport solutions. Our tunable transceivers, transmitter modules, and high-speed coherent components are essential to DWDM systems maximizing fiber capacity and minimizing cost per bit. For optical transport applications, we offer a broad range of products, including ROADMs, optical amplifiers, and optical channel monitors to efficiently switch, route, and condition optical signals. Our portfolio also includes pump lasers for optical amplifiers and passive components such as switches, attenuators, and wavelength-division multiplexing (WDM) systems. Beyond discrete components, we provide integrated modules, circuit packs, and subsystems for amplification, switching, and wavelength management. Additionally, our transport offerings include optical circuit switches for data center applications, helping to reduce power consumption and improve overall network efficiency. We also offer a comprehensive range of industrial lasers to address diverse manufacturing needs. Our fiber lasers deliver kilowatt-class output power and excellent beam quality, making them ideal for sheet metal processing and general manufacturing applications. Additionally, high-power, solid-state and ultrafast lasers are used by manufacturers for precision machining tasks like drilling in printed circuit boards, wafer singulation, glass cutting, and solar cell scribing. Our 3D sensing products are primarily laser light sources, including higher-performance vertical-cavity surface-emitting lasers (VCSELs) and VCSEL arrays. Strategy In optical networking, we focus on technology leadership through innovation in close partnership with our customers, cost leadership and functional and vertical integration. We align the latest technologies with industry-leading, scalable manufacturing and operations to make us a valuable partner for cloud data center and network operators, AI/ML infrastructure providers, and NEMs. We aim to drive the next phase of data center infrastructure and communication data network scaling with technologies and products that are faster, more energy-efficient, more agile and more reliable. 5 Table of Contents Our commitment to innovation, particularly in photonic integration, drives the development of optical products that meet the evolving demands of data centers. Each product generation offers enhanced functionality, reduced size, lower power consumption, and improved cost-effectiveness. By providing a wide range of innovative optical solutions, from components to integrated modules to complete systems, we enable our customers to build the high-performance data center and communication networks of today and engineer those of the future. In industrial lasers, we leverage our long-term relationships with OEM customers and our broad product and manufacturing technology portfolio to create innovative and valuable solutions that enable our customers to win in their markets. Customers During fiscal years 2026, 2025, and 2024, net revenue from a single end customer which represented 10% or more of our total net revenue of the applicable fiscal year is summarized in the table below: Years Ended June 27, 2026 June 28, 2025 June 29, 2024 Customer A 26.6 % 15.4 % 18.9 % Customer B 15.0 % 16.0 % 11.4 % International Operations During fiscal years 2026, 2025 and 2024, net revenue from customers outside the United States based on the geographic region and country where our product is initially shipped to represented 79.2%, 81.0% and 73.8% of net revenue, respectively. Frequently, customers request shipment of our products to their factories, contract manufacturer factories, or other locations in countries that differ from their headquarter location (which in many cases is in the U.S.). Our net revenue is primarily denominated in U.S. dollars, including our net revenue from customers outside the United States based on customer shipment locations as described above. Refer to “Note 17. Operating Segments and Geographic Information” to the consolidated financial statements. For information regarding risks associated with our international operations, refer to Item 1A “Risk Factors” of this Annual Report. Backlog Due to possible changes in product delivery schedules and cancellation of product orders, and because our sales often reflect orders shipped in the same quarter in which they are received, our backlog at any particular date is not necessarily indicative of actual revenue or the level of orders for any succeeding period. Competition We compete against various public and private companies providing photonic components, modules, and systems. Some of these competitors are also our customers for certain of our products. Seasonality Our revenue may be influenced on a quarter-to-quarter basis by customer demand patterns and new product introductions. Some of our products may be incorporated into consumer electronic products, which are subject to seasonality and fluctuations in demand. Mergers and Acquisitions We evaluate strategic opportunities regularly and, where appropriate, have acquired and expect to acquire in the future, additional businesses, products, or technologies that are complementary to, or broaden the markets for our products. We believe we have strengthened our business model by expanding our addressable markets, customer base and expertise, diversifying our product portfolio and fortifying our core businesses through acquisitions as well as through organic initiatives. Refer to “General - Overview” above and “Note 4. Business Combination” to the consolidated financial statements for additional information. Research and Development We devote substantial resources to research and development (“R&D”) for the development of new and enhanced products to serve our current markets and attractive new markets for our technology. We also expend significant engineering resources to enhance both product performance and our ability to manufacture products in greater volume and at lower cost. 6 Table of Contents We are maintaining our capability to provide leading products throughout the network, while focusing on several important sub-segments. We are making significant investments in next generation optical components for cloud data center and AI/ML applications, including higher speed and higher optical power laser chips for use in high-speed datacom transceivers and data interconnection solutions. We are also investing in the development of new high-speed optical transceiver modules for use in cloud data center, AI/ML, and DCI applications. In addition, we are investing in the emerging optical circuit switching market to enable direct data transmission between fiber optic cables in data centers within the optical plane. We continue to invest in research and development to develop innovative components and modules for telecommunications networks, such as higher capacity ROADMs and tunable laser and coherent components and transceiver modules needed for long-haul and metro applications. We are also responding to market needs for higher levels of integration, including the integration of optics, electronics and software in our modules, subsystems and circuit packs. We continue to develop new solid-state, fiber, and ultrafast short pulse lasers that leverage our technologies. These products are targeted at serving customers engaging in the semiconductor device, solar cell, display, and electric vehicle and battery manufacturing markets as well as broader materials processing and precision micromachining end-markets. We also continue to develop new and enhanced laser diode products with higher performance and efficiency at lower cost, primarily for the consumer end-market. Intellectual Property Intellectual property rights that apply to our various products include patents, trade secrets and trademarks. We do not intend to broadly license our intellectual property rights unless we can obtain adequate consideration or enter into acceptable patent cross-license agreements. As of June 27, 2026, we owned approximately 1,000 U.S. patents and 900 foreign patents with expiration dates through 2046 and had approximately 670 patent applications pending throughout the world. Manufacturing We use a combination of our own wafer fabrication facilities, or wafer fabs, assembly and test facilities, as well as third-party contract manufacturers to produce our products. Our significant manufacturing facilities are located in the United States, Thailand, China, the United Kingdom, Slovenia, and Japan. We expanded our manufacturing footprint through our various acquisitions, and in 2026, we continued to add to our footprint by acquiring a manufacturing facility in Greensboro, North Carolina. We have undertaken various initiatives to consolidate and restructure certain of our manufacturing and operational sites, particularly in light of efficiencies and synergies achievable from prior acquisitions, while also expanding overall manufacturing capacity for new and high growth product lines across our global manufacturing footprint. Our significant contract manufacturing partners are located primarily in Thailand, Taiwan, Malaysia and the Philippines. We rely on the capabilities of our contract manufacturers to plan and procure components and manage the inventory in these locations. Sources and Availability of Raw Materials We use various suppliers and contract manufacturers to supply parts and components for manufacturing and support of multiple product lines. Although our intention is to establish at least two sources of supply for materials whenever possible, for certain components we have sole or limited source supply arrangements. We may not be able to procure these components from alternate sources at acceptable prices and quality within a reasonable time, or at all, therefore, the risk of loss or interruption of such supply could impact our ability to deliver certain products on a timely basis. Risks associated with reliance on third parties for the timely and reliable delivery of raw materials are discussed in greater detail in Item 1A “Risk Factors” of this Annual Report. Human Capital Resources As of June 27, 2026, we employed approximately 13,757 full-time employees, including approximately 11,916 employees in manufacturing, 1,085 employees in R&D and 756 employees in SG&A. Of the 13,757 employees, approximately 1% are represented by two national collective bargaining agreements with local chapters in Slovenia and two labor unions in China. We believe that our relations with both our union and non-union employees are in good standing. We believe that our future performance relies on the strength of our employees, and our ability to recruit, retain, develop and motivate the services of executive, engineering, sales and marketing, and support personnel is critical to our success. We strive to meet these objectives by offering competitive pay and benefits in a diverse, inclusive and safe workplace and by providing opportunities for our employees to grow and develop their careers. 7 Table of Contents Competitive Pay and Benefits We provide compensation and benefits packages that we believe are competitive within the applicable market. We use a combination of compensation and other programs (which vary by region and salary grade) to attract, motivate and retain our employees, including semi-annual or annual performance bonuses, stock awards, an employee stock purchase plan, health savings and flexible spending accounts, paid time off, family leave, tuition assistance programs, health and wellness benefits and programs. We review our benefits packages annually, or more frequently as needed, to ensure we remain competitive with our peers and continue to attract and retain talent throughout our organization. Employee Recruitment, Retention and Development We are committed to recruiting, hiring, retaining, promoting and engaging a global, diverse workforce to best serve our global customers, suppliers, and partners. We have established relationships with professional associations and industry groups to proactively attract talent, and we partner with universities for our internship program. We believe that our commitment to our internship program and university partnerships contributes to developing the next generation of talent and provides a pipeline of recent college graduates into our talent pool. Material Government Regulations Our business activities are international and subject us to various federal, state, local and foreign laws in the countries in which we operate, and our products and services are subject to certain laws and regulations affecting the sale of our products. Environment Our R&D, manufacturing and distribution operations involve the use of hazardous substances and are regulated under international, federal, state and local laws governing health and safety and the environment. We apply strict standards for protection of the environment and occupational health and safety to sites inside and outside the United States, even if not subject to regulation imposed by foreign governments. We believe that our properties and operations at our facilities comply in all material respects with applicable environmental laws and occupational health and safety laws. However, the risk of environmental liabilities cannot be completely eliminated, and there can be no assurance that the application of environmental and health and safety laws will not require us to incur significant expenditures. We are also regulated under a number of international, federal, state and local laws regarding recycling, product packaging and product content requirements. The environmental, product content/disposal and recycling laws are gradually becoming more stringent and may cause us to incur significant expenditures in the future. In connection with our separation from JDSU and trading as an independent public company in 2015, we agreed to indemnify Viavi for any liability associated with contamination from past operations at all properties transferred to us from Viavi, to the extent the resulting issues primarily related to our business. We have not been presented with any claims to date. Global Trade and Export Controls As a global business, we operate in many jurisdictions and our products and services are subject to diverse and evolving import and export laws, including international treaties, U.S. export controls and sanctions, customs regulations, and local trade laws. These regulations may delay product launches, restrict our operations in certain regions, or limit dealings with specific entities or individuals, particularly where sensitive or controlled technology is involved. For instance, the U.S. and other governments have imposed restrictions on certain semiconductors and telecommunications products and components, which limit both sales of our products and our access to product components. At the same time, noncompliance with these trade regulations could significantly hinder our ability to operate in some markets or serve particular customers. For additional information concerning regulatory compliance and a discussion of the risks associated with governmental regulations that may materially impact us, refer to Item 1A “Risk Factors” of this Annual Report. Available Information Our website is located at www.lumentum.com, and our investor relations website is located at http://investor.lumentum.com. Copies of our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and amendments to these reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act, as amended, are available free of charge on our investor relations website as soon as reasonably practicable after we file such material electronically with or furnish it to the Securities and Exchange Commission (the “SEC”). The SEC also maintains a website that contains our SEC filings at www.sec.gov. 8 Table of Contents Investors and others should note that we routinely use the Investors section of our website to announce material information to investors and the marketplace. While not all of the information that we post on our corporate website is of a material nature, some information could be deemed to be material. Accordingly, we encourage investors, the media and others interested in us to review the information that we share on www.lumentum.com. Information in, or that can be accessed through, our website is not incorporated into this Form 10-K.