Simultaneous broadband generation of second and third harmonics from chirped nonlinear photonic crystals

• Published in: Light, science & applications Vol. 3; no. 7; p. e189
• Main Authors: Chen, Bao-Qin, Ren, Ming-Liang, Liu, Rong-Juan, Zhang, Chao, Sheng, Yan, Ma, Bo-Qin, Li, Zhi-Yuan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.07.2014; Springer Nature B.V
• Subjects: 639/624/399/1022; 639/624/400/385; Applied and Technical Physics; Atomic; Bandwidth; Broadband; Classical and Continuum Physics; Conversion; Displays; Harmonics; Lasers; Molecular; Nonlinearity; Optical and Plasma Physics; Optical Devices; Optics; original-article; Photonic crystals; Photonics; Physics; Physics and Astronomy; quasiphase matching; second-harmonic generation; chirped periodically poled lithium niobate; third-harmonic generation
• ISSN: 2047-7538; 2047-7538
• DOI: 10.1038/lsa.2014.70

Ultrabroadband laser sources are highly desirable in a wide variety of modern science disciplines ranging from physics, chemistry and materials science to information communications and processing. Here we present the design and fabrication of a chirped periodically poled lithium niobate (CPPLN) nonlinear photonic crystal that supports multiple orders of quasiphase matching with finite bandwidth and allows for the simultaneous broadband generation of second and third harmonics with high conversion efficiency. Moreover, the chirp rate has a significant influence on the conversion efficiency and bandwidth. The CPPLN scheme offers a promising approach for the construction of short-wavelength laser sources and enables the generation of the three primary colors—red, green and blue—from a single crystal, which may have potential applications in large-screen laser displays. Nonlinear optics: multicolour crystals Developments in crystal engineering may soon allow the simultaneous generation of red, green and blue light from a single material. Bao-Qin Chen and co-workers from China and Australia have designed and fabricated a nonlinear optical crystal of chirped periodic-poled lithium niobate. They fabricated the crystal by periodically poling a sample of lithium niobate with an electric field, while varying the period along the length of the crystal. When optically pumped, the resulting chirped-crystal supports both second- and third-harmonic generation, thus allowing the simultaneous emission of many shorter wavelengths. Conversion efficiencies are as high as 30% for second-harmonic generation and 2% for third-harmonic generation. The scheme could be a promising approach for realizing a suitable optical source for laser display technology or photoelectron spectrometers.