LARS, the Laser Absolute Reference Spectrograph of the Kiepenheuer-Institute is a scientific instrument for the ultramodern observation of the Sun at the Vacuum Tower Telescope (VTT) at the Observatorio del Teide on Tenerife. LARS enables the measurement of the solar spectrum of a selected field-of-view with the high-resolution Echelle-spectrograph of the VTT. Additionally, the emission spectrum of the newly installed Laser Frequency Comb is superimposed with the solar spectrum. Since each emission peak of the comb spectrum represents one well-defined frequency, the solar spectrum can be calibrated on an absolute wavelength scale. Figuratively, the comb serves as a ruler for the spectral lines. The accuracy is of the order of m/s or below and is therefore a multiple better than former devices. The successful upgrade of the Laser Frequency Comb in May 2016 enables the continuous operation of this worldwide unique spectroscopic observation of the Sun.