Vacuum tight connection using heat fusion - is made between metal retaining ring and optical fibre disc covering ring opening

摘要

The retaining ring (2) together with the optical fibre disc (1) is brought evenly to a high temperature just below the softening point of the optical fibre disc. A high-frequency field is then generated to produce heating of the retaining ring so that it is fused into the disc. After the high-frequency field has been switched off, the fused ring and the fibre disc are cooled to a temperature corresponding roughly to the first temperature. They are held at this temperature for some time and are then cooled to room temperature.