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
Original Manuscript: January 2, 1996
Published: July 1, 1996
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)