Highly Efficient Infrared Optical Nonlinearity of a Wide-Bandgap Chalcogenide Li2CdGeS4
A quaternary chalcogenide Li2CdGeS4 is an excellent candidate for a nonlinear optical (NLO) material exhibiting wide transparency spanning from its fundamental band edge (3.15 eV) to the terahertz regime (23.5 μm). Strong optical nonlinearity of Li2CdGeS4 has been investigated over a wide spectral range 𝜆=1.064–3.3 μm based on second- and third-harmonic generation. The compound has a high damage threshold at λ=1.064 μm because of saturable three-photon absorption, and is phase-matchable for λ>1.5 μm with 𝜒(2)≃50 pm/V. It also exhibits strong third-order nonlinearity of 𝜒(3)≃105 pm2/V2. Li2CdGeS4 is promising for high-power NLO applications in the broad infrared spectrum.
Jang, Joon I.; Clark, Daniel J.; Brant, Jacilynn A.; Aitken, Jennifer A.; and Kim, Yong Soo, "Highly Efficient Infrared Optical Nonlinearity of a Wide-Bandgap Chalcogenide Li2CdGeS4" (2014). Chemistry and Physics Faculty Articles. 166.