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 mm 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 mm 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 AE10%. The ability to create custom designed longitudinal emission profiles was demonstrated. The variations of the polar and azimuth radiance emission diagrams were within AE15% 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 $5 mm. Maximum power distribution is >0.5