Highly sensitive setup for tunable wavelength hyper-Rayleigh scattering with parallel detection and calibration data for various solvents

Abstract

A very sensitive experimental setup for accurate wavelength-dependent hyper-Rayleigh scattering (HRS) measurements of the molecular first hyperpolarizability beta in the broad fundamental wavelength range of 600 to 1800 nm is presented. The setup makes use of a stable continuously tunable picosecond optical parametric amplifier with kilohertz repetition rate. To correct for multi-photon fluorescence, a small spectral range around the second harmonic wavelength is detected in parallel using a spectrograph coupled to an intensified charge-coupled device. Reliable calibration against the pure solvent is possible over the full accessible spectral range. An extensive set of wavelength-dependent HRS calibration data for a wide range of solvents is presented, and very accurate measurements of the beta dispersion of the well-known nonlinear optical chromophore Disperse Red 1 are demonstrated.

Syntheses, Crystal Structures and Photophysical Measurements of Phosphite‐Substituted Schiff Base and Azobenzene Li­gands

“…Many nonlinear optical chromophores exhibit significant two-photon fluorescence (2PF). [32,36] This has sometimes led to overestimation of the β values obtained from HRS measurements. Since the 2PF spectrum is typically much broader than the HRS spectrum, spectral measurements are the most reliable way to distinguish between HRS and 2PF.…”

“…Since the 2PF spectrum is typically much broader than the HRS spectrum, spectral measurements are the most reliable way to distinguish between HRS and 2PF. [32,36] In this work, the HRS signal is measured with two different detection bandwidths to assess possible 2PF contamination of the HRS signal. The 60 cm -1 (1.6 nm) bandwidth includes the entire HRS spectrum but may also include significant 2PF.…”

Nonlinear optics on nano/micro-hierarchical structures on metals: focus on symmetric and plasmonic effects

“…Here, HRS is incoherent second-harmonic (SH) scattering from small feature structures based on Mie theory; up to now, HRS signals from spherical and non-spherical lacking centrosymmetric structures have been observed [39,40]. Hence, the consideration of HRS is important, and the experimental setup has been referred to in some papers [38,41]. Following polarization selection, the reflected SHG light signals were detected by a photomultiplier tube (PMT).…”

Theory-Guided Design of Organic Electro-Optic Materials and Devices

“…Experimentally, the acentric order parameter can be defined using techniques such as attenuated total reflection (ATR) [83][84][85], two-slit interferometry (TSI) [86,87], Fabry-Perot interferometry (FPI) [88], or a Mach Zehnder interferometric technique (MZI) [89], which permit measurement of both of the two non-zero electro-optic tensor elements, r 33 and r 13 , for poled OEO materials. The acentric order parameter can be extracted either from the ratio of r 33 /r 13 or from r 33 alone if the elements of the molecular first hyperpolarizability tensor (e.g., β zzz ) are correctly estimated from a combination of quantum mechanical calculations and hyper-Rayleigh scattering (HRS) measurements [53,90,91] and/or electric field induced second harmonic generation (EFISH) measurements [16]. Figure 5 illustrates the variation of the ratio r 33 /r 13 with LAP optical power (orientation-selective heating) illustrating how these change with increasing order.…”