Second harmonic generation (SHG) is a nonlinear optical process that occurs when non-centrosymmetric materials are probed with high-energy laser excitation. The process was discovered in quartz in 1962 and it occurs when two photons at the frequency of the laser excitation combine to emit a third...
The second order nonlinear susceptibility tensor element {xxx} of (2) () in 卤-quartz is calculated using a full band structure approach. A scissor operator is applied to the band structure obtained from the first-principles OLCAO method using local density approximation (LDA). The calculated ...
Second-harmonic generation was observed in an elastic surface wave propagating in the y direction on the x surface of α-quartz. The waves were generated and detected by means of interdigital electrode transducers. The fundamental frequency was 9 MHz. The amplitude of the second-harmonic signal ...
Second harmonic generation SHG may be used as an experimental technique in structural crystallography. By applying a bond polarizability model to the nonlinear optical coefficients of quartz, the rotation of the SiO4 tetrahedron with temperature is `observed'. Additionally, the oxygen positional parameter...
Potassium titanyl phosphate, KTiOPO4 (KTP) is one of the best nonlinear optical materials increasingly being used commercially for the second harmonic generation (SHG) and parametric oscillation since its discovery and introduction in 1976 [88]. KTP crystals are mechanically, chemically, and thermally...
Quasi-phase-matched second harmonic generation in crystal quartz QuartzSecond-harmonic generationNonlinear crystalsDeep ultravioletLasersLight sourcesNonlinear optical materialsOptical materialsTransparency M Harada,KI Muramatsu,S Kurimura - 《Proceedings of Spie the International Society for Optical Engineering》 ...
Upon wavelength modulation, the absorbed optical power is distributed over different harmonics of the excitation frequency, including DC, and only a fraction of 34% (at optimum modulation parameters) is centered at the second harmonic [25]. For IM, this fraction can be significantly higher, ...
A new optical study of the first order α‐β quartz transition (573 °C) shows an intimate mixing of the two phases which produces small angle scattering for fundamental and second harmonic light. The previously known "critical" opalescence is most probably related to Dauphiné twinning. In all...
In the QEPAS system, wavelength modulation and second harmonic (2 f) demodulation technology were employed to suppress effectively background noise. A high-frequency sine wave and a low-frequency ramp wave were combined and then sent into the laser controller for wavelength modulation of the ...
(2001) who measured Q by second harmonic generation (SHG), the tem- perature evolution of lattice parameters and the transition entropy, and observed these inter-grain effects. Mechanical parameters, such as RUS signals, were measured by McKnight et al. (2008) who found no significant ...