After the discovery of quantum mechanics in the early 20 th century, lots of progress was made in using quantum effects. Many applications became part of everyday's life. Today, we are at the beginning of the second quantum revolution, that will not only use quantum effects indirectly, but aims at controlling quantum states and using this for a variety of new applications such as quantum computing, information processing, sensing and metrology. The laser, a tool from the first quantum revolution, will play a major role. Many quantum systems based on optical transitions, such as single atoms, ions or artificial atoms require lasers for the initialization and manipulation. Many of them demand "high-quality photons", that is a laser with stable frequency, low linewidth, high beam quality and single-mode frequency tunability. External cavity diode lasers (ECDL) meet these requirements. In addition, each quantum system requires a specific combination of wavelengths and power levels. TOPTICA Photonics offers the broadest wavelength coverage from 190 nm to 4 µm based on direct diode lasers and filling the optical gap with frequency converted diode lasers. For a variety of applications, the output power of an ECDL in the range of a few mW up to approximately 150 mW is not sufficient. Using tapered amplifier chips in a master oscillator power amplifier (MOPA) configuration, commercially available output powers up to 4 W can be achieved while maintaining the properties of the master oscillator, i.e. singlefrequency and single-spatial mode operation. R&D results of even higher output power of "high-quality photons" are presented.