Ultra-low feedback fibre end termination geometry for high power fibre source applications

Optical fibre end termination techniques are very important in the development of fibre-based optical communication systems and high-power fibre sources in laser, amplifier and superfluorescent configurations. There are many situations where unwanted optical feedback from a fibre end-facet can be very detrimental to the performance of the fibre source. For example, in laser configurations in which an external cavity is employed to extend the functionality (e.g. for Q-switching, mode-locking or wavelength tuning), then feedback from the fibre end-facet adjacent to the external cavity will compete with the feedback provided by the external cavity itself and hence may impact adversely on the laser output characteristics.