Wellenleiter und Verbindungselement

The invention relates to a waveguide (1) with a first longitudinal section (11), which has at least one core (21) with a first refractive index (n K ) and a sheath (22) surrounding said core with a second refractive index (n M ), it being possible for at least one optical signal (S) to be guided in the core (21), and the waveguide (1) furthermore has a third longitudinal section (13) with the sheath (22) and a coating (23) surrounding said sheath with a third refractive index (nB), it being possible for the optical signal to be guided in the sheath (22) in the third longitudinal section (13), and the waveguide (1) has a second longitudinal section (12), which connects the first longitudinal section (11) and the third longitudinal section (13) and in which the signal may be conducted over from the core (21) onto the sheath (22).