The laser applicator includes a catheter (10) having a proximal section (10a), a midsection (10b) and a distal end section (10c). It contains a light guide, the light of which is output in a decoupling portion (40). The light guide runs in a longitudinal groove on the outside of a catheter body. While the light guide (20) is continuous, the catheter is composed of catheter bodies, which are joined together at a catheter splice site (37).
