Lens-ended fibers for medical applications: a new fabrication technique

Abstract

Microlens-ended fibers may be of great usefulness in medical applications, in particular in endoscopic laser treatment and surgery. Previous fabrication techniques of integral microlenses have mainly faced the problems related to optical communications, where damage due to high-power lasers does not occur. We describe a novel method, the laser-microfurnace technique, which uses the laser energy delivered by the fiber itself to create a microfurnace in a suitable material that reirradiates energy in a different wavelength band and causes the fiber tip to melt. This easy and reliable method is applicable to all types of fiber, even those with pure-silica core and large core diameter. No special equipment or training of the operator is required, so fabrication of microlenses may be carried out even in the surgery room. Experimental process parameters are reported.