illustrated in fig1 b with reference to a section parallel to a longitudinal axis 40 analogously to fig1 a as already in the embodiment according to fig1 a support unit 30 of the embodiment according to fig1 b also forms a cavity in which there are contained two insulation layers 31 and 33 a piezoelement 32 and a laser diode unit 34 in contrast to the variant embodiment according to fig1 a laser diode unit 34 is initially enclosed by first insulation layer 33 next by piezoelement 32 as a pressure generating element then by second insulation layer 31 and finally by support unit 30 in this way it is possible to generate with pressure generating element 32 a force that acts on laser diode unit 34 from all radial directions that is substantially perpendicularly to longitudinal axis 40 illustrated in fig2 is an exit window 50 as it is arranged axially on support element 30 illustrated in fig1 exit window 50 essentially comprises a frame element 70 and a laterally arranged insulation layer 61 an opening 60 being provided both through frame element 70 and through insulation layer 61 also drawn in fig2 is a cutting plane a a which forms the basis for the section through the exit window 50 illustrated in fig3 fig3 depicts exit window 50 illustrated in fig2 in section along cutting plane a a fig2 through the section parallel to longitudinal axis 40 frame element 70 becomes a u shaped part into which there is inserted a semitransparent window 51 which stands substantially perpendicular to the propagation direction that is to.