Protective sheath for monomode directional coupler - is collapsed at each end of coupling distance with glass solder between collapsed regions and incoming or outgoing optical fibres

摘要

The protective sheath includes two sheath sections (2,3) which are connected to a tube-shaped sheath (1). The sheath sections are of a material having the same expansion coefficient as that of the directional coupler. The sheath is collapsed in two regions, each at a distance from the respective end (1.1,1.2) of the sheath, by melting on to the incoming or outgoing optical fibres (4.1,5.1; 4.2,5.2). A glass solder is arranged between the collapsed regions and the incoming or outgoing optical fibres. ADVANTAGE - Is insensitive to fluctuations in temperature and is durably hermetically tight.