Background and objectives: Cylindrical fiber diffusers are common tools in photodynamic therapy (PDT). However, large outer diameter and short length limit the indications to which they can be applied. Here a diffuser with an outer diameter of 250 microm and an active length exceeding 5 cm was developed.
Study design/materials and methods: Diffusers based on photosensitive quartz optical fibers with a cladding diameter of 140 microm were developed using a structured beam from an excimer laser. A complete set of photometric characteristics, including longitudinal, polar, and azimuth radiance emission diagrams were collected.
Results and conclusions: The longitudinal radiance emission is homogenous to within +/-10%. The ability to create custom designed longitudinal emission profiles was demonstrated. The variations of the polar and azimuth radiance emission diagrams were within +/- 15% from an ideal Lambertian emitter. The polar uniformity can be improved with a slight increase of the outer diameter using a diffusing recoating compound. The residual light leakage at the distal end of the fiber diffuser was suppressed to 2%. The minimal bending radius after recoating is approximately 5 mm. Maximum power distribution is > 0.5 W cm(-1).
Copyright 2005 Wiley-Liss, Inc.