Hollow‑core Optical Fiber

A hollow‑core optical fiber is a strand of glass or polymer that carries light not through solid material but through an empty central channel. The surrounding cladding is patterned with tiny air holes arranged in a regular lattice, which creates a photonic bandgap that keeps the light confined to the void. In contrast to conventional fibers where most of the light travels inside the silica core, the hollow‑core design lets the beam spend almost all of its path in air, dramatically reducing interaction with the material itself.

Because the light avoids the bulk glass, the fiber can transmit very high‑intensity beams without suffering from nonlinear effects or damage that would occur in solid cores. It also offers lower attenuation for certain wavelength ranges, making it attractive for long‑distance communication, precision sensing, and delivery of powerful laser pulses used in manufacturing or medical procedures. Researchers exploit these advantages when they need to move light efficiently across distances while preserving its spectral purity.

Hollow‑core fibers appear wherever the combination of low loss, high power handling, and a desire to keep the light mostly in air is valuable. They are found in experimental telecom links that aim to push data rates beyond what conventional silica can sustain, in scientific setups that guide ultrashort laser pulses for spectroscopy or material processing, and increasingly in emerging technologies such as gas‑filled nonlinear optics where the hollow channel can be loaded with gases to create new light‑matter interactions.