Third-order nonlinear optical response in transparent solids using ultrashort laser pulses

• Published in: Applied physics. B, Lasers and optics Vol. 107; no. 3; pp. 703 - 709
• Main Authors: Dota, K., Dharmadhikari, J. A., Mathur, D., Dharmadhikari, A. K.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.06.2012
• Subjects: Engineering; Lasers; Optical Devices; Optics; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Quantum Optics; Optical Kerr Effect; Probe Beam; Pump Beam; BaF2; Diffraction Efficiency
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-012-4935-7

The third-order optical nonlinearity, χ (3) , is measured in transparent glasses (BK7 and fused silica) and crystals (BaF 2 and quartz) using 36-fs, 800-nm laser pulses and the optical Kerr gate (OKE) technique; values are found to lie in the range 1.3–1.7×10 -14  esu, in accordance with theoretical estimates. We probe the purely electronic response to the incident ultrashort laser pulse in fused silica and BK7 glass. In BaF 2 and quartz, apart from the electronic response we also observe contribution from the nuclear response to the incident ultrashort pulses. We observe oscillatory modulations that persist for ∼400 fs. The response of the media (glasses and crystals) to ultrashort pulses is also measured using two-beam self-diffraction; the diffraction efficiency in the first-order grating is measured to be in the range of 0.06–0.13 %. Third harmonic generation due to self-phase matching in the transient grating geometry is measured as a function of temporal delay between the two incident ultrashort pulses, yielding the autocorrelation signal.