Micro non-planar ring oscillator (micro-NPRO

NASA Goddard Space Flight Center has developed a specifically shaped, smaller NPRO using a higher-doped Neodymium (Nd) crystal, helping to stabilize spatial modes and removing problems in frequency and polarization. This NPRO eliminates a technology gap between micro-chip lasers and traditional NPROs. Previous non-planar ring oscillator (NPRO) designs have stability issues in terms of frequency, polarization, beam quality, mode choice, and output power due to the fact that the non-linear cavity design length prevents avoidance of spatial hole burning. Furthermore, large NPRO crystals are susceptible optical loss and not compatible with opto-mechanical parts and electro-optics developed for standard diode lasers.