• Cat-intel
  • MedIntelliX
  • Resources
  • About Us
  • Request Free Sample ×

    Kindly complete the form below to receive a free sample of this Report

    Leading companies partner with us for data-driven Insights

    clients tt-cursor

    Germany Optical Transport Network Market

    ID: MRFR/ICT/54107-HCR
    200 Pages
    Aarti Dhapte
    September 2025

    Germany Optical Transport Network Market Research Report By Technology (Wavelength Division Multiplexer, Dense Wavelength Division Multiplexer, Others), By Service (Network Design, Network Support, Others), By Component (Optical Switch, Optical Packet Platform, Others) and By End-user (IT/Telecom, Healthcare, Retail, Government, Others)- Forecast to 2035

    Share:
    Download PDF ×

    We do not share your information with anyone. However, we may send you emails based on your report interest from time to time. You may contact us at any time to opt-out.

    Germany Optical Transport Network Market Research Report - Forecast to 2035 Infographic
    Purchase Options
    $ 4,950.0
    $ 5,950.0
    $ 7,250.0
    Table of Contents

    Germany Optical Transport Network Market Summary

    The Germany Optical Transport Network market is projected to grow significantly from 971 USD Million in 2024 to 2045 USD Million by 2035.

    Key Market Trends & Highlights

    Germany Optical Transport Network Key Trends and Highlights

    • The market is expected to reach 2045 USD Million by 2035, indicating robust growth.
    • A compound annual growth rate of 7.01 percent is anticipated from 2025 to 2035.
    • The market valuation is set to increase from 971 USD Million in 2024 to 2045 USD Million by 2035.
    • Growing adoption of optical transport technologies due to increasing demand for high-speed data transmission is a major market driver.

    Market Size & Forecast

    2024 Market Size 971 (USD Million)
    2035 Market Size 2045 (USD Million)
    CAGR (2025-2035) 7.01%

    Major Players

    Nokia, Ciena Corporation, NEC Corporation, Deutsche Telekom, ZTE Corporation, Calix, Huawei Technologies, Cisco Systems, Infinera, Mitsubishi Electric, Ericsson, Fujitsu Limited, Broadcom, Adva Optical Networking, Juniper Networks

    Germany Optical Transport Network Market Trends

    The Germany Optical Transport Network Market is witnessing significant transformation driven by the increasing demand for high-speed internet connectivity and advancements in telecommunications infrastructure. The push for digital transformation across various sectors, supported by the German government's initiatives for the expansion of broadband networks, has accelerated the adoption of optical transport technologies. With an emphasis on the 5G rollout and the enhancement of existing fiber-optic networks, there is a growing trend towards deploying more sophisticated optical transport solutions. 

    This is not only expected to improve network efficiency but also enhance service delivery across urban and rural areas.In detail still to be covered is the possibility of collaboration between telecom companies and technology providers in developing industry-specific solutions like smart cities and IoT solutions. Also, changing Germany into a more environmentally friendly economy is enhancing the focus on the development of optical transport devices and systems. Businesses that can take advantage of green technologies will be in the best market positions.

    There is increasing investment in optical networks in Germany because the government is also investing in improving the digital infrastructure of the country in its latest digital strategy.

    This is complemented by ongoing policy support aimed at increasing access to high-speed internet across the country, thus bolstering growth in the optical transport network segment. Overall, the focus on enhancing connectivity and bandwidth capacity, combined with ongoing technological advancements, defines the current landscape of Germany's Optical Transport Network Market.

    Germany Optical Transport Network Market Drivers

    Market Segment Insights

    Germany Optical Transport Network Market Segment Insights

    Germany Optical Transport Network Market Segment Insights

    Optical Transport Network Market Technology Insights

    Optical Transport Network Market Technology Insights

    The Germany Optical Transport Network Market, particularly within the Technology segment, is characterized by a robust and evolving landscape driving significant advancements in telecommunications infrastructure. With the growing demand for high-bandwidth applications fueled by digital transformation and increased internet traffic, technologies such as Wavelength Division Multiplexer (WDM) and Dense Wavelength Division Multiplexer (DWDM) play vital roles in enhancing network capacity and efficiency. 

    WDM technology, which enables multiple data streams to be transmitted simultaneously over a single optical fiber by utilizing different wavelengths of laser light, is of particular importance as it significantly boosts the transmission capabilities of existing networks without requiring additional fiber installations.This efficiency leads to cost reductions and improved performance, making WDM an essential element in modern optical transport systems. Another crucial aspect is the Dense Wavelength Division Multiplexer, which takes this technology further by packing more wavelengths into a single fiber, thereby maximizing bandwidth utilization even in heavily populated urban areas across Germany. 

    This is paramount as the nation continues to experience exponential data growth, particularly in sectors like cloud computing, big data analytics, and the Internet of Things (IoT).The segment classified as 'Others' encompasses various emerging technologies and innovations that are gradually becoming integral to optical transport solutions. This could include advancements such as optical networking advancements, innovative modulation formats, and improvements in network management systems. German infrastructure is heavily investing in these realms, emphasizing innovation and adaptability to facilitate the increasing demand for high-speed connectivity. 

    Overall, the Technology segment within the Germany Optical Transport Network Market is positioned to grow significantly, fueled by ongoing advancements and the continuous need for improved efficiency and capacity in optical communications.With Germany aiming to fortify its digital backbone, the integration of these technologies promises to support various industries and enhance overall economic throughput, driven by improved connectivity and reliable data transmission solutions.

    Optical Transport Network Market Service Insights

    Optical Transport Network Market Service Insights

    The Service segment of the Germany Optical Transport Network Market is integral to the overall growth and functionality of the industry. This segment encompasses various key aspects, such as Network Design, Network Support, and Other services that cater to the increasing demand for high-capacity and robust optical transport infrastructures. Network Design is particularly crucial, as it lays the foundation for optimizing network performance while accommodating the evolving needs of businesses and consumers in Germany.

    As the country continues to invest in advanced telecommunications infrastructure, the importance of effective design cannot be overstated.Network Support services further ensure that existing systems run smoothly and efficiently, addressing potential issues before they escalate and significantly adding value to service providers. 

    The Other services category captures a range of ancillary offerings that enhance the optical network ecosystem, providing innovation and comprehensive solutions tailored to various customer requirements. The robust Germany Optical Transport Network Market revenue growth is powered by these services, which play a pivotal role in addressing the demands of an increasingly digital and connected economy.

    Optical Transport Network Market Component Insights

    Optical Transport Network Market Component Insights

    The Germany Optical Transport Network Market is experiencing robust growth, driven by a growing demand for high-capacity data transmission and the need for efficient communication infrastructure. Within the Component segment, critical areas such as Optical Switch and Optical Packet Platform play a vital role, with Optical Switches being essential for directing data traffic efficiently within the network.

    These components are significant for managing bandwidth and ensuring optimal performance of communication services, reflecting the increasing complexity of network architectures.The Optical Packet Platform is also noteworthy as it supports the evolving needs for data packet transmission, ensuring that operators can deliver high-speed internet and voice services essential in a digitally connected Germany. 

    Moreover, the presence of advanced telecommunication regulations and initiatives from the German government to promote higher broadband penetration heightens the importance of these components in creating a reliable, future-ready network. The overall market dynamics indicate a trend towards more sophisticated network solutions, allowing service providers to stay competitive in the rapidly growing digital economy.Challenges include the need for large capital investments and maintaining the security and reliability of network infrastructure amidst the evolving technological landscape.

    Overall, the Germany Optical Transport Network Market is poised for continued evolution, with component segments leading the way in facilitating advancements in connectivity and data delivery.

    Optical Transport Network Market End-user Insights

    Optical Transport Network Market End-user Insights

    The End-user segment of the Germany Optical Transport Network Market encompasses various sectors, each playing a crucial role in driving overall market growth. The IT and Telecom industries are particularly significant as they heavily rely on optical transport networks for high-speed data transmission and increased bandwidth. Healthcare is emerging as a critical player as well, with optical networks supporting telemedicine and data-intensive applications, enhancing the efficiency of patient care services.

    Meanwhile, the Retail sector leverages optical transport networks to optimize supply chains and improve customer experience through high-speed connectivity.The Government sector uses these networks for secure communication and efficient data management, reflecting its importance in public services and national security. 

    Additionally, other industries contribute to market diversification, enriching the sector through innovative applications and services. As connectivity demands surge across these sectors, market trends indicate a robust shift towards deploying advanced optical transport solutions, positioning the Germany Optical Transport Network Market as an essential backbone for the nation's digital infrastructure.Market players are presented with ample opportunities to innovate and cater to these diverse needs, boosting Germany's credibility as a tech-forward nation.

    Get more detailed insights about Germany Optical Transport Network Market Research Report - Forecast to 2035

    Regional Insights

    Key Players and Competitive Insights

    The Germany Optical Transport Network Market is characterized by a dynamic landscape where various telecommunications entities compete for a share in an ever-growing demand for high-speed data services. This market is driven by the need for a robust infrastructure to support data transmission and telecommunications services across the country. Advancements in optical technologies have opened up new possibilities for service providers to enhance their network capabilities, resulting in an increased emphasis on reliability, speed, and cost-effectiveness.

    As the shift towards digitalization intensifies, understanding the competitive dynamics becomes crucial for stakeholders aiming to establish a foothold or expand in this lucrative market.

    Nokia has a significant presence in the Germany Optical Transport Network Market, leveraging its extensive experience and technological expertise to offer high-performance infrastructure solutions. The company stands out due to its commitment to innovation and quality, providing advanced optical transport solutions that cater to the needs of diverse customers, including service providers and enterprises. Nokia's strengths lie in its strong R&D capabilities, enabling continuous improvements in network architectures and service offerings. Its effective collaborations with various telecommunications companies in Germany enhance its market position, ensuring a competitive edge through tailored services and localized support.

    Furthermore, Nokia's ability to integrate advanced technologies within its optical transport solutions allows it to address the evolving needs of the telecommunications ecosystem, making it a prominent player in the market.

    Ciena Corporation has strategically positioned itself in the Germany Optical Transport Network Market by focusing on delivering high-capacity optical networking solutions and services designed to meet the increasing demands of bandwidth. The company's key product offerings in this region include scalable optical transport systems and advanced software-defined networking solutions, enabling operators to optimize their networks effectively. Ciena's strengths include its innovation in coherent optical technology and its proven track record in enhancing network performance and resilience. The company's commitment to customer-centric solutions is reinforced by partnerships and an active presence in local telecommunications initiatives.

    Additionally, Ciena's strategic mergers and acquisitions strengthen its competitive position in Germany by integrating complementary technologies and expanding its portfolio, aiding in addressing rapidly evolving customer needs in the region.

    Key Companies in the Germany Optical Transport Network Market market include

    Industry Developments

    The Germany Optical Transport Network Market has seen several notable developments in recent months. In September 2023, Deutsche Telekom announced its plans to expand its optical transport network to enhance broadband services, leveraging technologies from partners such as Nokia and Ciena Corporation. Furthermore, NEC Corporation has been actively advancing its optical technologies in the region, focusing on efficient data transmission and low-latency applications, which is essential given Germany's push for digital transformation. The market is also witnessing significant growth, with the increasing demand for high-capacity data transmission spurring investments from companies like ZTE Corporation and Calix. 

    This growth trend is further supported by a strategic partnership between Adva Optical Networking and various local telecom operators to modernize infrastructure. In terms of mergers and acquisitions, in August 2023, Ericsson completed the acquisition of a German technology firm specializing in optical networking solutions, significantly boosting its operational capabilities in the region. Additionally, recent advances in fiber optic technologies from Huawei Technologies and Cisco Systems are contributing to the overall enhancement of the optical transport infrastructure in Germany. Overall, the sector is poised for substantial expansion driven by innovation and strategic collaborations among key players.

    Market Segmentation

    Outlook

    • IT/Telecom
    • Healthcare
    • Retail
    • Government
    • Others

    Report Scope

     
    Report Attribute/Metric Source: Details
    MARKET SIZE 2023 903.84(USD Million)
    MARKET SIZE 2024 971.0(USD Million)
    MARKET SIZE 2035 2045.0(USD Million)
    COMPOUND ANNUAL GROWTH RATE (CAGR) 7.006% (2025 - 2035)
    REPORT COVERAGE Revenue Forecast, Competitive Landscape, Growth Factors, and Trends
    BASE YEAR 2024
    MARKET FORECAST PERIOD 2025 - 2035
    HISTORICAL DATA 2019 - 2024
    MARKET FORECAST UNITS USD Million
    KEY COMPANIES PROFILED Nokia, Ciena Corporation, NEC Corporation, Deutsche Telekom, ZTE Corporation, Calix, Huawei Technologies, Cisco Systems, Infinera, Mitsubishi Electric, Ericsson, Fujitsu Limited, Broadcom, Adva Optical Networking, Juniper Networks
    SEGMENTS COVERED Technology, Service, Component, End-user
    KEY MARKET OPPORTUNITIES Rising demand for high-speed connectivity, Expansion of 5G infrastructure, Growth in cloud services adoption, Increased focus on data security, Upgrading legacy network systems
    KEY MARKET DYNAMICS Rising internet traffic demand, 5G network expansion, Increasing reliance on cloud services, Need for low latency solutions, Growing adoption of AI technologies
    COUNTRIES COVERED Germany

    Market Highlights

    Author
    Aarti Dhapte
    Team Lead - Research

    She holds an experience of about 6+ years in Market Research and Business Consulting, working under the spectrum of Information Communication Technology, Telecommunications and Semiconductor domains. Aarti conceptualizes and implements a scalable business strategy and provides strategic leadership to the clients. Her expertise lies in market estimation, competitive intelligence, pipeline analysis, customer assessment, etc.

    Leave a Comment

    FAQs

    What is the projected market size of the Germany Optical Transport Network Market by 2035?

    The Germany Optical Transport Network Market is expected to be valued at 2045.0 USD Million by 2035.

    What is the expected compound annual growth rate (CAGR) for the Germany Optical Transport Network Market from 2025 to 2035?

    The expected CAGR for the Germany Optical Transport Network Market from 2025 to 2035 is 7.006%.

    What is the market size of the Wavelength Division Multiplexer segment in 2024?

    The Wavelength Division Multiplexer segment is valued at 360.0 USD Million in 2024.

    What market value is projected for the Dense Wavelength Division Multiplexer segment by 2035?

    The Dense Wavelength Division Multiplexer segment is expected to reach a market value of 1150.0 USD Million by 2035.

    Who are the leading players in the Germany Optical Transport Network Market?

    Key players in the market include Nokia, Ciena Corporation, NEC Corporation, and Deutsche Telekom among others.

    What is the market size for the Others segment of the Germany Optical Transport Network Market in 2024?

    The Others segment of the market is valued at 111.0 USD Million in the year 2024.

    What is the projected market size for the Wavelength Division Multiplexer segment by 2035?

    The Wavelength Division Multiplexer segment is projected to be valued at 765.0 USD Million by 2035.

    How does the total market value for the Germany Optical Transport Network Market compare between 2024 and 2035?

    The total market value is expected to grow from 971.0 USD Million in 2024 to 2045.0 USD Million in 2035.

    What are the growth drivers for the Germany Optical Transport Network Market?

    Growth drivers include increased demand for high-speed data transmission and advancements in optical technologies.

    What challenges might the Germany Optical Transport Network Market face in the coming years?

    Potential challenges include fierce competition among key players and rapid technological changes impacting market dynamics.

    1. EXECUTIVE
    2. SUMMARY
    3. Market Overview
    4. Key Findings
    5. Market Segmentation
    6. Competitive Landscape
    7. Challenges and Opportunities
    8. Future Outlook
    9. MARKET INTRODUCTION
    10. Definition
    11. Scope of the study
    12. Research Objective
    13. Assumption
    14. Limitations
    15. RESEARCH
    16. METHODOLOGY
    17. Overview
    18. Data
    19. Mining
    20. Secondary Research
    21. Primary
    22. Research
    23. Primary Interviews and Information Gathering
    24. Process
    25. Breakdown of Primary Respondents
    26. Forecasting
    27. Model
    28. Market Size Estimation
    29. Bottom-Up
    30. Approach
    31. Top-Down Approach
    32. Data
    33. Triangulation
    34. Validation
    35. MARKET
    36. DYNAMICS
    37. Overview
    38. Drivers
    39. Restraints
    40. Opportunities
    41. MARKET FACTOR ANALYSIS
    42. Value chain Analysis
    43. Porter's
    44. Five Forces Analysis
    45. Bargaining Power of Suppliers
    46. Bargaining
    47. Power of Buyers
    48. Threat of New Entrants
    49. Threat
    50. of Substitutes
    51. Intensity of Rivalry
    52. COVID-19
    53. Impact Analysis
    54. Market Impact Analysis
    55. Regional
    56. Impact
    57. Opportunity and Threat Analysis
    58. Germany
    59. Optical Transport Network Market, BY Technology (USD Million)
    60. Wavelength
    61. Division Multiplexer
    62. Dense Wavelength Division Multiplexer
    63. Others
    64. Germany
    65. Optical Transport Network Market, BY Service (USD Million)
    66. Network
    67. Design
    68. Network Support
    69. Others
    70. Germany
    71. Optical Transport Network Market, BY Component (USD Million)
    72. Optical
    73. Switch
    74. Optical Packet Platform
    75. Others
    76. Germany
    77. Optical Transport Network Market, BY End-user (USD Million)
    78. IT/Telecom
    79. Healthcare
    80. Retail
    81. Government
    82. Others
    83. Competitive Landscape
    84. Overview
    85. Competitive
    86. Analysis
    87. Market share Analysis
    88. Major
    89. Growth Strategy in the Optical Transport Network Market
    90. Competitive
    91. Benchmarking
    92. Leading Players in Terms of Number of Developments
    93. in the Optical Transport Network Market
    94. Key developments
    95. and growth strategies
    96. New Product Launch/Service Deployment
    97. Merger
    98. & Acquisitions
    99. Joint Ventures
    100. Major
    101. Players Financial Matrix
    102. Sales and Operating Income
    103. Major
    104. Players R&D Expenditure. 2023
    105. Company
    106. Profiles
    107. Nokia
    108. Financial
    109. Overview
    110. Products Offered
    111. Key
    112. Developments
    113. SWOT Analysis
    114. Key
    115. Strategies
    116. Ciena Corporation
    117. Financial
    118. Overview
    119. Products Offered
    120. Key
    121. Developments
    122. SWOT Analysis
    123. Key
    124. Strategies
    125. NEC Corporation
    126. Financial
    127. Overview
    128. Products Offered
    129. Key
    130. Developments
    131. SWOT Analysis
    132. Key
    133. Strategies
    134. Deutsche Telekom
    135. Financial
    136. Overview
    137. Products Offered
    138. Key
    139. Developments
    140. SWOT Analysis
    141. Key
    142. Strategies
    143. ZTE Corporation
    144. Financial
    145. Overview
    146. Products Offered
    147. Key
    148. Developments
    149. SWOT Analysis
    150. Key
    151. Strategies
    152. Calix
    153. Financial
    154. Overview
    155. Products Offered
    156. Key
    157. Developments
    158. SWOT Analysis
    159. Key
    160. Strategies
    161. Huawei Technologies
    162. Financial
    163. Overview
    164. Products Offered
    165. Key
    166. Developments
    167. SWOT Analysis
    168. Key
    169. Strategies
    170. Cisco Systems
    171. Financial
    172. Overview
    173. Products Offered
    174. Key
    175. Developments
    176. SWOT Analysis
    177. Key
    178. Strategies
    179. Infinera
    180. Financial
    181. Overview
    182. Products Offered
    183. Key
    184. Developments
    185. SWOT Analysis
    186. Key
    187. Strategies
    188. Mitsubishi Electric
    189. Financial
    190. Overview
    191. Products Offered
    192. Key
    193. Developments
    194. SWOT Analysis
    195. Key
    196. Strategies
    197. Ericsson
    198. Financial
    199. Overview
    200. Products Offered
    201. Key
    202. Developments
    203. SWOT Analysis
    204. Key
    205. Strategies
    206. Fujitsu Limited
    207. Financial
    208. Overview
    209. Products Offered
    210. Key
    211. Developments
    212. SWOT Analysis
    213. Key
    214. Strategies
    215. Broadcom
    216. Financial
    217. Overview
    218. Products Offered
    219. Key
    220. Developments
    221. SWOT Analysis
    222. Key
    223. Strategies
    224. Adva Optical Networking
    225. Financial
    226. Overview
    227. Products Offered
    228. Key
    229. Developments
    230. SWOT Analysis
    231. Key
    232. Strategies
    233. Juniper Networks
    234. Financial
    235. Overview
    236. Products Offered
    237. Key
    238. Developments
    239. SWOT Analysis
    240. Key
    241. Strategies
    242. References
    243. Related
    244. Reports
    245. LIST
    246. OF ASSUMPTIONS
    247. Germany Optical Transport Network Market
    248. SIZE ESTIMATES & FORECAST, BY TECHNOLOGY, 2019-2035 (USD Billions)
    249. Germany
    250. Optical Transport Network Market SIZE ESTIMATES & FORECAST, BY SERVICE, 2019-2035
    251. (USD Billions)
    252. Germany Optical Transport Network Market
    253. SIZE ESTIMATES & FORECAST, BY COMPONENT, 2019-2035 (USD Billions)
    254. Germany
    255. Optical Transport Network Market SIZE ESTIMATES & FORECAST, BY END-USER, 2019-2035
    256. (USD Billions)
    257. PRODUCT LAUNCH/PRODUCT DEVELOPMENT/APPROVAL
    258. ACQUISITION/PARTNERSHIP
    259. LIST
    260. Of figures
    261. MARKET SYNOPSIS
    262. GERMANY
    263. OPTICAL TRANSPORT NETWORK MARKET ANALYSIS BY TECHNOLOGY
    264. GERMANY
    265. OPTICAL TRANSPORT NETWORK MARKET ANALYSIS BY SERVICE
    266. GERMANY
    267. OPTICAL TRANSPORT NETWORK MARKET ANALYSIS BY COMPONENT
    268. GERMANY
    269. OPTICAL TRANSPORT NETWORK MARKET ANALYSIS BY END-USER
    270. KEY
    271. BUYING CRITERIA OF OPTICAL TRANSPORT NETWORK MARKET
    272. RESEARCH
    273. PROCESS OF MRFR
    274. DRO ANALYSIS OF OPTICAL TRANSPORT NETWORK
    275. MARKET
    276. DRIVERS IMPACT ANALYSIS: OPTICAL TRANSPORT NETWORK
    277. MARKET
    278. RESTRAINTS IMPACT ANALYSIS: OPTICAL TRANSPORT
    279. NETWORK MARKET
    280. SUPPLY / VALUE CHAIN: OPTICAL TRANSPORT
    281. NETWORK MARKET
    282. OPTICAL TRANSPORT NETWORK MARKET, BY TECHNOLOGY,
    283. (% SHARE)
    284. OPTICAL TRANSPORT NETWORK MARKET, BY TECHNOLOGY,
    285. TO 2035 (USD Billions)
    286. OPTICAL TRANSPORT NETWORK
    287. MARKET, BY SERVICE, 2025 (% SHARE)
    288. OPTICAL TRANSPORT
    289. NETWORK MARKET, BY SERVICE, 2019 TO 2035 (USD Billions)
    290. OPTICAL
    291. TRANSPORT NETWORK MARKET, BY COMPONENT, 2025 (% SHARE)
    292. OPTICAL
    293. TRANSPORT NETWORK MARKET, BY COMPONENT, 2019 TO 2035 (USD Billions)
    294. OPTICAL
    295. TRANSPORT NETWORK MARKET, BY END-USER, 2025 (% SHARE)
    296. OPTICAL
    297. TRANSPORT NETWORK MARKET, BY END-USER, 2019 TO 2035 (USD Billions)
    298. BENCHMARKING
    299. OF MAJOR COMPETITORS

    Germany Optical Transport Network Market Segmentation

    • Optical Transport Network Market By Technology (USD Million, 2019-2035)

      • Wavelength Division Multiplexer
      • Dense Wavelength Division Multiplexer
      • Others

     

    • Optical Transport Network Market By Service (USD Million, 2019-2035)

      • Network Design
      • Network Support
      • Others

     

    • Optical Transport Network Market By Component (USD Million, 2019-2035)

      • Optical Switch
      • Optical Packet Platform
      • Others

     

    • Optical Transport Network Market By End-user (USD Million, 2019-2035)

      • IT/Telecom
      • Healthcare
      • Retail
      • Government
      • Others

     

     

     

     

     

     

    Report Infographic
    Free Sample Request

    Kindly complete the form below to receive a free sample of this Report

    Customer Strories

    “I am very pleased with how market segments have been defined in a relevant way for my purposes (such as "Portable Freezers & refrigerators" and "last-mile"). In general the report is well structured. Thanks very much for your efforts.”

    Victoria Milne Founder
    Case Study

    Chemicals and Materials