Hollow-core light rods are functional optical transmission devices with a central hollow structure. Their core design is similar to that of hollow-core fibers, where light primarily propagates through the hollow section (typically vacuum or gas-filled) rather than through a traditional solid material core. Compared to solid light rods, their structural feature lies in utilizing the principles of total internal reflection and wave properties of light, enabling efficient transmission of optical signals or specific optical effects through specialized hollow-channel designs. For instance, some hollow-core light rods can be filled with inert gases to broaden spectra or compress laser pulses, playing a role in high-energy laser technology.

1. High-Energy Laser Technology

Hollow-core light rods can achieve efficient compression of laser pulses by filling them with inert gases (such as argon). For example, in one experiment, a hollow-core light rod with a 250μm inner diameter compressed a 40fs pulse from a titanium-sapphire laser to 7fs, with a single pulse energy exceeding 1mJ, providing a critical tool for ultrafast laser physics research.

2. Optical Communication and Data Transmission

Although hollow-core light rods have not yet been directly applied in commercial communication networks, their principles are similar to those of hollow-core fibers, and they may play a role in ultra-low latency scenarios in the future. For instance, the hollow structure can reduce the refractive index of light transmission, lowering latency from 5μs/km in traditional fibers to 3.46μs/km—a 30% reduction compared to existing systems—making them suitable for latency-sensitive applications such as data centers and computing power networks.

3. Specialized Optical Sensing

Some hollow-core light rods can be combined with components like fiber Bragg gratings to form sensing devices. For example, by detecting changes in the optical properties of gases within the hollow channel, high-precision measurements of physical quantities such as temperature and pressure can be achieved.