Abstract: The current invention concerns a laser beam generating device and a method for adjusting a wavelength of a laser beam. The current invention addresses the objective of further improving laser beam generation and wavelength adjustment. The current invention particularly allows for simplifying the combination of laser source elements such that they operate at different, but controlled, wavelengths with their beams overlapping. The laser beam generating device (100) comprises at least one laser source element (11) and an external cavity. The external cavity comprises an output coupler (40) and a periodic filter element (30) arranged between the laser source element (11) and the output coupler (40). The laser beam generating device is characterized in that the laser beam generating device further comprises at least two cut-off filter elements (21, 22) each arranged between the laser source element (11) and the periodic filter element (30).