The FQCW266 series lasers are characterized by their excellent beam properties. Regardless of the model, all products impress with their quasi unmatched coherence length of > 1000 m and their spectral linewidth of < 300 kHz. The lasers are equipped with a resonant frequency conversion stage, emit single-frequency laser radiation at 266.050 nm, are available in a nominal power range from 10 mW to 1 W and stand out for their energy efficiency.