Laser beam delivery is crucial in fields like surgery, micromachining and scientific applications like spectroscopy. Hollow-core photonic crystal fiber (HCPCF) technology, with its exceptional energy and power handling, is becoming a recognized component in several industries. However, this maturity and industrial adoption have been limited to the infrared and visible spectral ranges. For instance, the UV and DUV ranges have been scarcely addressed, and UV-DUV laser beam delivery remains a challenge due to effects like solarization of most solid materials when exposed to light below 300 nm.


We report on the development of inhibited-coupling HCPCF (IC-HCPCF) with record-low transmission loss


of < 50 dB/km at 266 nm, and solarization-free. 2 meter-long IC-HCPCF patchcords, connectorized with SMA terminations were made and their UV handling and life-span were tested. A laser beam of a 266 nm wavelength laser-source, emitting 1 ns wide and 37 µJ energy pulses, was injected into the IC-HCPCF patchcord, achieving a total transmission rate of 93%. The laser beam was kept continuously coupled into the patchcord for over 680 hrs. The results show excellent stability of the transmitted power (fluctuations of less than 5 %), as well as the fibre output mode quality. To our knowledge this is the first fiber guidance of DUV laser that combines high energy handling and long lifespan. The results mark a major milestone in the adoption of fiber UV laser beam delivery by the industrial community.