From Copper to Hollow-Core: The Evolution and Future of Fiber Optic Technology

The journey of fiber optic technology is one of the most remarkable stories in modern telecommunications. From early experiments with light transmission to today’s cutting-edge hollow-core fibers, fiber optics has continuously evolved to meet the world’s growing demand for faster, more reliable, and higher-capacity data transmission. This article explores the historical milestones of fiber optics and provides a forward-looking view of emerging technologies that will shape the networks of the future.

1. Early Concepts: Light as a Carrier

The idea of using light for communication is not new. As early as the 19th century, scientists experimented with transmitting light through water jets and glass rods. In 1870, British physicist John Tyndall demonstrated that light could follow a curved path through a stream of water, laying the conceptual foundation for total internal reflection.

The first real breakthrough came in the 1950s and 1960s, when researchers developed the concept of optical waveguides—structures capable of guiding light through glass fibers by reflecting it internally. However, early fibers suffered from extremely high signal loss (over 1,000 dB/km), making them impractical for communication.

2. The Breakthrough: Low-Loss Fiber (1970)

The modern fiber optic era began in 1970, when Corning Glass Works (now Corning Incorporated) announced the development of low-loss optical fiber with attenuation below 20 dB/km, achieved by using ultra-pure fused silica glass. This breakthrough made it feasible to use optical fibers for long-distance communication.

Shortly after, semiconductor laser technology advanced, providing reliable light sources that could be coupled into the fiber. Together, these innovations set the stage for commercial fiber optic communication systems in the late 1970s and early 1980s.

3. Commercial Deployment and Global Expansion

In the 1980s and 1990s, fiber optic cables began to replace traditional copper cables in long-distance telephony and undersea communications. The benefits were clear:

• Extremely high bandwidth

• Low signal attenuation

• Immunity to electromagnetic interference

• Smaller size and lighter weight compared to copper

Submarine fiber optic cables connected continents, and terrestrial networks expanded rapidly. By the late 1990s, the Internet boom created unprecedented demand for high-capacity backbone infrastructure, which fiber optics was uniquely positioned to deliver.

4. Technological Advancements: DWDM and Beyond

One of the biggest leaps in fiber capacity came with the development of Dense Wavelength Division Multiplexing (DWDM) in the 1990s. DWDM allowed multiple wavelengths (channels) of light to be transmitted simultaneously through a single fiber, multiplying capacity by orders of magnitude.

Other key innovations included:

• Erbium-Doped Fiber Amplifiers (EDFAs) – enabling signal amplification over long distances without electrical conversion.

• Improved connectors and splicing technologies – reducing loss and improving reliability.

• Bend-insensitive fibers and G.657 standards – improving performance in compact data center environments.

These technologies turned fiber optics into the backbone of the global Internet and enabled the explosion of bandwidth-hungry applications such as video streaming, cloud computing, and mobile broadband.

5. The Present: 5G, Cloud, and Data Centers

Today, fiber optics is everywhere—from international submarine cables spanning oceans to FTTH (Fiber to the Home) connections delivering gigabit Internet to consumers.

The rise of 5G networks, hyperscale data centers, and edge computing continues to push the boundaries of fiber performance. Network operators demand ultra-low latency, high density, and massive capacity—requirements that traditional singlemode fibers are meeting impressively, but not indefinitely. This pressure has led researchers to explore new fiber technologies to overcome fundamental physical limits.

6. The Future: Hollow-Core Fiber Technology

Among the most exciting developments in recent years is hollow-core fiber (HCF). Unlike conventional fibers that guide light through a solid glass core, hollow-core fibers guide light through an air-filled core, using a special microstructured cladding to confine light.

This unique design offers several significant advantages:

• Ultra-low latency: Light travels about 30% faster in air than in glass, so hollow-core fibers can reduce signal latency by up to 30–50% compared to standard singlemode fibers. This is critical for financial trading, cloud computing, and real-time applications.

• Lower nonlinearity and scattering: Since the core is mostly air, hollow-core fibers have reduced nonlinear effects, allowing for higher signal quality over long distances.

• Potential for higher power handling: Ideal for specialized applications such as sensing or high-power laser delivery.

Recent advancements have made hollow-core fibers commercially viable, with companies like Lumenisity (now part of Microsoft) demonstrating HCF cables suitable for real-world deployment. Early trials show impressive performance for data center interconnects and metropolitan backbone networks.

7. Other Emerging Fiber Innovations

In addition to hollow-core fibers, several other technologies are pushing the boundaries of fiber performance:

• Multi-core fibers (MCF): Multiple cores within a single cladding increase capacity without increasing cable size.

• Few-mode and space-division multiplexing fibers: Exploit multiple spatial modes to multiply data throughput.

• Photonic crystal fibers: Tailor light propagation through microstructured claddings, enabling novel dispersion and guidance properties.

These innovations aim to meet the exponential growth in global data traffic, projected to reach hundreds of zettabytes annually within the next decade.

8. Conclusion

The evolution of fiber optic technology is a testament to human ingenuity. From early glass rods with enormous losses to today’s ultra-low-loss fibers carrying terabits per second, fiber has transformed global communication. Now, as networks approach the physical limits of traditional singlemode fibers, next-generation technologies like hollow-core and multi-core fibers are paving the way for the future.

These advancements will enable faster, more efficient, and more scalable networks, supporting innovations such as 6G, AI-driven applications, and quantum communications. Just as fiber optics revolutionized the 20th century’s telecommunication landscape, hollow-core and advanced fibers are set to define the infrastructure of the 21st century.