Abstract: A spectral imaging device with a narrow band spectrally tunable light source. The light source includes an optical parametric oscillator that can be tuned across a wide range of wavelengths while illuminating a target. In a preferred embodiment, a Q-switched YAG laser pumps the OPO. Two-dimensional images of the target may be detected at various wavelengths by a imaging sensor with a many pixel focal plane array to generate data arrays known as hyper-spectral image cubes. These images detecting variations is optical parameters including transmission, reflectivity, and fluorescence of the target can be obtained in various spectral ranges from ultraviolet to infrared for a variety of applications in metrology, agriculture, life sciences, and in the pharmaceutical industry.

Abstract: An optical parametric oscillator for converting the wavelength of a laser pump beam into a signal wavelength and an idler wavelength. A co-linear double resonance cavity is created with a right angle prism serving as a maximum reflector for both the pump beam as well as the signal and idler beams. A non-linear crystal is positioned within said resonance cavity and is pivoted to tune the oscillator. A pump beam deflector is positioned to deflect the pump beam into the resonance cavity. The deflector preferably is a mirror with a multi-layer coating configured to provide maximum reflection at the wavelength of the pump beam and maximum transmittal of the signal and idler beams over their ranges. The pump beam passes twice through said non-linear crystal and is efficiently converted into said signal and idler beams in said non-linear crystal. The deflector can be placed inside or outside the cavity. In a preferred embodiment the output coupler is an uncoated window.