An optoelectrical assembly (1) has a modular frequency-doubled solid state laser (2), which is fixed so as to be aligned therein, with an optical resonator (3) which is connected in a thermally conducting manner to a heat source (5) which is controllable by controlling means (4). The operating temperature (T) of the solid state laser (2) is adjusted by the controlling means (4) to between 40.degree. C. and 55.degree. C.