As India races towards a fully digitalised economy, the demand for robust fibre optic infrastructure has never been more pressing. Initiatives such as Digital India and the BharatNet pro­ject aim to bridge the urban-rural divide, connecting over 250,000-gram panchayats with broadband. Yet, the scale of this ambition is staggering. According to industry estimates, by 2030, India is projected to boast 980 million 5G subscribers and 100 million fibre-to-the-home (FTTH) connections, fuelling a fibre optics market expected to surge from its current valuation ($0.55 billion) to $1.03 billion by 2031. This explosive growth is underpinned by the proliferation of data centres to support e-commerce, streaming, remote work and emerging technologies such as artificial intelligence (AI) and internet of things.

At the heart of this expansion lies optical fibre, the invisible backbone of modern connectivity. Conventional silica fibres, the workhorses of global telecom since the 1970s, guide light through a solid glass core, surrounded by a cladding of slightly lower refractive index. However, as India’s networks strain under mounting data loads, traditional silica-based fibres are revealing their inherent bottlenecks. Issues such as latency caused by the refractive index of glass, signal distortion over long distances and non-linear effects at high power levels make it increasingly difficult to extract more performance out of existing fibre systems.

In this scenario, hollow-core fibre (HCF) technology is poised to redefine optical transmission. Instead of carrying light through solid glass, HCFs guide photons through a hollow air-filled core, with the cladding structure ensuring confinement of the light beam. Since light travels almost 50 per cent faster in air than in glass, HCF promises dramatically lower latency, higher information throughput, reduced non-linearity and more efficient energy transmission. Here, photons propagate primarily through air, slashing latency by up to 45 per cent over equivalent distances. Early prototypes have demonstrated losses as low as 0.091 dB/km – nearly half that of silica – enabling signals to travel farther without regeneration and boosting capacity by three times through reduced non-linear distortions. For countries such as India, which are balancing twin priorities of digital inclusion and cutting-edge innovation, HCF represents an opportunity to leapfrog into the next era of connectivity.

Early deployments

While HCF has been the subject of academic research since the late 1990s, only in recent years has it crossed the threshold into real-world deployment. Some global technology leaders have taken the first steps.

Microsoft has tested HCF to accelerate cloud data centre connectivity. For hyperscale players such as Microsoft Azure, where even microseconds of latency translate into competitive advantage, HCF is being explored to cut down delays in high-performance computing workloads and AI model training.

Across the Pacific, China Mobile has similarly accelerated HCF adoption, leveraging its state-backed research and development (R&D) ecosystem, which has trialled HCF in metropolitan backbones. The operator has looked at HCF as a way to increase network efficiency in dense urban environments, where latency-sensitive applications such as autonomous driving, immersive augmented reality/virtual reality and cloud gaming are expected to proliferate.

Yet, these successes mask formidable challenges that could hamper HCF’s global roll-out. Manufacturing remains a bottleneck. Fabricating the nanoscale cladding – often nested glass tubes or nested anti-resonant nodeless (NANF) structures – demands precision drawing towers operating at 1,800 °C, yielding defect rates 20-30 per cent higher than silica. Costs, currently two to three times those of standard single-mode fibre, stem from low yields and specialised materials such as low-expansion glass, though economies of scale from hyperscalers such as Microsoft could halve these prices in the future. Moreover, because HCF propagates most energy in air, it is vulnerable to dust and gas contaminants, requiring clean installations and rigorous quality control. Additionally, the splicing and integration of HCF with existing fibre networks remain technically challenging, since telecom operators cannot overhaul their entire installed fibre base overnight. Ensuring compatibility with conventional fibre systems – at landing stations, metro backbones, or enterprise networks – is a crucial step before mass adoption. Another issue lies in long-haul transmission losses. While recent innovations have significantly reduced attenuation in HCF, conventional fibre still holds the edge over very long distances. Hybrid models, where HCF is used selectively for latency-sensitive or high-performance links, while conventional fibre handles bulk traffic, and emerging as the most viable near-term pathway.

For operators in India, these trials offer blueprints but underscore the need for localised adaptation. Bharti Airtel and Reliance Jio, already investing billions in FTTH, could pilot HCF in high-density corridors such as Mumbai-Delhi, but only if vendors address cost and splicing via indigenous innovation. As deployments evolve, overcoming these barriers will determine whether HCF becomes a ubiquitous upgrade or remains a niche premium.

Strategic potential

The true promise of HCF lies in the strategic applications it can unlock, well beyond the conventional broadband.

  • Quantum technologies: India is already investing in quantum research through initiatives such as the National Quantum Mission. Quantum key distribution and quantum networking rely on the transmission of fragile quantum states of photons, which are highly susceptible to noise and distortion in traditional silica fibres. HCF, with its lower scattering and non-linear effects, can preserve quantum states over longer distances with higher fidelity. This makes it a strong candidate for secure quantum communication backbones, particularly for government, financial institutions and critical infrastructure operators.
  • Defence: For the defence sector, HCF opens up opportunities in secure, low-latency and high-bandwidth communications systems. Military operations that depend on real-time intelligence, remote piloting of drones, or encrypted command-and-control networks can benefit from the reduced latency and enhanced security of HCF. Moreover, because HCFs can potentially handle higher power levels, they are also being investigated for directed energy systems and other advanced defence technologies.
  • Undersea cable landing stations: India is positioning itself as a global hub for submarine cable landings, with multiple hyperscalers and carriers investing in new routes connecting Asia, Africa, Europe and North America. Submarine cables form the backbone of global internet traffic and latency reduction on these routes directly impacts global financial markets, cloud services and digital commerce. HCF could play a transformative role in undersea landing stations, where shaving off milliseconds in latency can provide competitive differentiation for India’s digital economy.
  • AI-driven networks and data centres: The rise of AI is rewriting demands placed on the network infrastructure. Training large-scale AI models requires massive clusters of GPUs and interconnects with extremely low latency. HCF can provide ultra-fast data exchange within and between data centres, helping India’s AI ecosystem become globally competitive. Telecom operators, meanwhile, are preparing for AI-driven networks that adapt in real time to traffic conditions; HCF’s low latency and high bandwidth can serve as a foundational enabler for such smart networks.

The Make in India opportunity

India’s optic fibre cable sector focuses on silica. This offers an entry opportunity for HCF players via PLI extensions for specialty fibres. Premier research institutions such as IIT Madras and CSIR could spearhead R&D in innovation in HCF. Additionally, smart cities, defence corridors and 5G/6G test beds could serve as controlled environments for piloting HCF. This would allow Indian vendors to refine splicing, integration and cost-efficiency techniques in real-­world conditions. Further, HCF’s lower energy footprint aligns with net zero goals and could attract FDI. Parallelly, just as the Semiconductor Mission has received government backing, HCF could benefit from targeted incentives under India’s telecom and digital infrastructure policies. Finally, partnering with international pioneers in HCF research and deployment could accelerate India’s learning curve. Joint ventures with global hyperscalers, submarine cable consortiums, or defence allies could bring both investment and knowledge transfer.

In sum

The convergence of India’s data demands with the unique capabilities of HCF marks a pivotal juncture for the national network infrastructure. By investing aggressively in HCF research and manufacturing, India can leapfrog traditional technological constraints, secure its digital future and elevate its strategic position in global telecom, defence, quantum and AI-driven industries.

Nikhaar Gogna