Nanosecond optical parametric oscillator with 90° image rotation: design and performance

According to numerical models of nanosecond optical parametric oscillators, cavities with 90° image rotation can produce high-quality beams even if the Fresnel number of the cavity is large. We review the properties of such image-rotating cavities and present a method for designing them. The laboratory performance of one promising design is characterized, demonstrating its ability to produce high-quality beams with good efficiency.