Up-Conversion of Near Infrared to Visible Radiation in Lithium-meta-Niobate

Abstract
Single‐crystal lithium niobate pumped with pulsed ruby‐laser radiation has been used to convert 1.7‐μ radiation to green light with more than 1% efficiency. A narrow infrared bandwidth of 17 Å, set by the phase‐matching requirement only, allows the up‐converter and photomultiplier to operate in place of a monochromator and infrared detector, and the emission spectrum of a mercury lamp has been thus examined in the region of 1.7 μ. A close agreement between theory and practice has been found in all respects except noise performance. Further studies of this aspect are required.