Development of LED Inks for Optical Fiber Applications
Microwave powered, mercury-based UV lamps have historically been the primary resource when curing inks used for optical fiber. They offer a broadband spectrum of UV light allowing formulators to take advantage of multiple wavelengths to initiate free radical polymerization. This facilitates surface and through cure, making use of both shorter and longer wavelengths.
However, these benefits do not come without certain drawbacks. Only a percentage of the light emitted by microwave lamps is available in the UV range and only a fraction of that is available at wavelengths absorbed by photoinitiators. When also taking into consideration other limitations such as high electrical power consumption and shorter lifetimes compared to LED1, the need for an alternative source for UV radiation becomes apparent.