High temperature miniature oven with low thermal gradient for processing fiber Bragg gratings

A miniature oven for processing fiber Bragg gratings in excess of 1000 °C has been projected and evaluated. The dimensions and the design of the oven allow rapid insertion and removal of the fiber during heating and minimizes mechanical degradation of the fiber. The 22 mm long oven has a flat zone at 1000 °C of 16 mm with a temperature variation of less than 2% and 20 mm with a temperature variation of 10%. The long term stability (hours) is ±20 °C measured at the center of the oven at 1000 °C. Rapid heating is possible, and heating optical fibers to 1000 °C shows a delay of approximately 400 ms before the core reaches thermal equilibrium.