Yellow monochromatic sources are useful in biomedical, remote sensing, and spectroscopy applications, but laser emission around 600 nm is difficult to achieve. Professor Juan Capmany of the Universidad Miguel Hernández (Elche, Spain) led a group that achieved generation of continuous-wave yellow laser light in a neodymium (Nd3+)-doped, periodically poled, lithium-niobate bulk crystal.
End-pumping of the crystal with a Ti:sapphire laser achieved simultaneous oscillation in π polarization of the two laser “channels” in Nd3+ at 1084.4 and 1373.6 nm. Intracavity quasi-phase-matched self-sum-frequency mixing of these two infrared laser waves generated yellow lasing at 606 nm. The yellow laser reached a power of 15.6 mW from an absorbed pump power of 314 mW. The research demonstrates the potential for monolithic microchip yellow lasers that can be directly pumped by commercial diode lasers. “This is the first example of a yellow laser in which two infrared laser waves around 1060 and 1300 nm were simultaneously oscillated and self-sum-frequency mixed in the same crystal to yield yellow laser radiation,” said Capmany. Contact Juan Capmany at [email protected].