Abstract
Purpose :
Femtosecond lasers continue to revolutionize the field of minimally invasive surgery. Unique properties of the ultra-short pulses are very useful in variety of medical applications ranging from general surgery, otolaryngology and dentistry to ophthalmology. In some applications the use of conventional optical fiber laser beam delivery is a common and convenient way to deliver the laser energy to the target tissue. However, the uses of conventional fiber-based beam delivery for ultra-short laser pulses are limited due to the optical fiber’s dispersion. Recently hollow-core photonic crystal fibers have been developed to address these limitations.
Methods :
We evaluated the properties of Kagome hollow-core photonic crystal fiber PMC-C-Yb-7C (GLOphotonics SAS, Limoges, France) and its potential applications in ultra-short laser beam delivery systems. The femtosecond laser beam was launched into the Kagome fiber via variable NA optical system designed to focus the laser beam to match the beam waist to fiber mode field diameter and the numerical aperture of the fiber. We evaluated the coupling efficiency, near and far field intensity profiles, fiber bend optical losses as well as peak power handling capability. The Frequency Resolved Optical Gating (FROG) was used to measure pulse duration broadening at the fiber output.
Results :
The femtosecond laser was coupled to the Kagome fiber with 94.8% coupling efficiency. The transmission loss measured were 2.3% per 2 meter. This resulted in attenuation of -0.05 dB per meter at the design wavelength 1030 nm. Particular emphasis was given to the study of the beam quality and transmission losses as a function of the bending radius down to 20 mm. The femtosecond laser pulses were transmitted with virtually no pulse width broadening due to close to zero dispersion (~1 fs/nm/meter) at design 1030 nm wavelength.
Conclusions :
Our study revealed that hollow core photonic crystal fibers have the potential to be used for femtosecond laser beam delivery. Its attributes of close to zero dispersion at the design wavelength, absence of Fresnel reflections from the fiber-end faces, high damage threshold and low transmission and bend losses down to 30 mm bend radius render it a viable option to femtosecond beam delivery to target tissue. This new technology provides the basis for ultra-short and high power laser beam delivery.
© 2015 Abbott Medical Optics Inc.
SC2015RF0021
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.