High-power single-spatial-mode near-IR laser diodes are mixed in periodically poled LiNbO3 (PPLN) to generate broadly tunable mid IR-radiation. Conversion efficiencies to the mid IR up to 0.017%/W are demonstrated, and up to 31 µW of power is generated at the spectroscopically important 4.3-µm wavelength. We achieved broadband mid-IR tunability by mixing a wavelength-tunable laser-diode pump source with a fixed-wavelength master oscillator power amplifier laser-diode signal source in a PPLN sample that has a poling period that varies from 21.0 to 22.6 µm in the direction transverse to the beam propagation. We generated mid-IR radiation from 4.1 to 4.3 µm with these laser sources, using a fixed 22.0-µm period region of the sample.
© 1996 Optical Society of America
A. Balakrishnan, S. Sanders, S. DeMars, J. Webjörn, D. W. Nam, R. J. Lang, D. G. Mehuys, R. G. Waarts, and D. F. Welch, "Broadly tunable laser-diode-based mid-infrared source with up to 31 µW of power at 4.3-µm wavelength," Opt. Lett. 21, 952-954 (1996)