Verrillon® VSS200 Series 125/155 μm Polyimide Fiber is a high numerical aperture (NA) single-mode fiber designed for a wide range of applications including sensing, illumination and communications. The high-temperature polyimide coating allows this fiber to be used in applications up to 300°C. Due to its 0.21 numerical aperture, this fiber exhibits exceptionally low bend-loss. The high germanium content also provides photosensitivity to UV light, useful in Fiber Bragg Grating (FBG) writing for sensing applications. In addition to polyimide, this fiber is also available in all Verrillon coatings and coating combinations for low and mid-temperature range.