Abstract: An optical coupling device for coupling light in between two optical waveguide end faces, in which the geometric position of one optical waveguide end face can be varied with respect to the other optical waveguide end face with the aid of a variable-length element. The element carries one of the two optical waveguides, and is connected to the other optical waveguide via a holding block. The variable-length element is connected to a variable-length compensating element, whose length changes with temperature by the same amount but in the opposite sense as that of the variable-length element. The variable-length compensating element is fixed to the second holding block.