Nonlinear Optical Phenomena in a Silicon-Smectic A Liquid Crystal (SALC) Waveguide

• Published in: Materials Vol. 12; no. 13; p. 2086
• Main Authors: Lembrikov, Boris I, Ianetz, David, Ben-Ezra, Yosef
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 28.06.2019; MDPI
• Subjects: Anisotropy; Electric fields; Lasers; Light; Light scattering; Liquid crystals; Long range order; Motion picture directors & producers; Nematic crystals; Nonlinear optics; Nonlinearity; Optical properties; optical waveguide; Optics; Organic materials; Phase modulation; Phase transitions; Photonics; Silicon; silicon photonics; smectic A liquid crystal (SALC); stimulated light scattering (SLS); Thin films; Waveguides; silicon photonics; smectic A liquid crystal (SALC); stimulated light scattering (SLS); optical waveguide
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma12132086

Liquid crystals (LCs) are organic materials characterized by the intermediate properties between those of an isotropic liquid and a crystal with a long range order. The LCs possess strong anisotropy of their optical and electro-optical properties. In particular, LCs possess strong optical nonlinearity. LCs are compatible with silicon-based technologies. Due to these unique properties, LCs are promising candidates for the development of novel integrated devices for telecommunications and sensing. Nematic liquid crystals (NLCs) are mostly used and studied. Smectic A liquid crystals (SALCs) have a higher degree of long range order forming a layered structure. As a result, they have lower scattering losses, specific mechanisms of optical nonlinearity related to the smectic layer displacement without the mass density change, and they can be used in nonlinear optical applications. We theoretically studied the nonlinear optical phenomena in a silicon-SALC waveguide. We have shown theoretically that the stimulated light scattering (SLS) and cross-phase modulation (XPM) caused by SALC nonlinearity can occur in the silicon-SALC waveguide. We evaluated the smectic layer displacement, the SALC hydrodynamic velocity, and the slowly varying amplitudes (SVAs) of the interfering optical waves.