High-power laser sources have essential applications in the fields of industry and research. However, the spectral gain of the active medium often limits the output power of highly demanded laser sources at uncommon wavelengths. Driven by higher requirements of industry and science, laser sources with process-optimized emission wavelengths represent a key technology in our society. Among other systems, Raman lasers provide an excellent technology to shift and adapt the emission spectrum to the process. These are less complex than comparable systems based on other nonlinear effects such as optical parametric gain. In this work, high-performance diamond-based Raman oscillators are developed and realized in double and single resonant operation to shift the emissions spectrum into the infrared range. Furthermore, parasitic nonlinear effects are shown and a method of their suppression is presented. Two different fiber-based lasers were developed for oscillator operation, which were used as pump sources for the Raman frequency converters. Both pump Wavelength 1060 nm and 1018 nm and the corresponding Raman frequency converters were used to shift the output spectrum into the infrared range. Going beyond the state of the art, high continuous wave power of 105Wat 1234 nm and 56Wat 1178 nm were shown for the single resonant Diamond- Raman-Oscillator. Furthermore, a double resonant system was developed to shift the emission spectrum even further into the infrared range to 1477 nm. The Raman oscillators have been characterized at high powers in a modulated and continuous mode operation. In particular, the transient behavior of the double-resonant oscillator was investigated. Here, an unstable behavior strongly dependent on the resonator length and the power range was found. In addition, upcoming intense pulse trains and spectral broadenings were investigated.