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The surface-enhanced coherent anti-Stokes Raman scattering (SECARS) from a self-assembled monolayer (SAM) of benzenethiol on a silver-coated surface-enhanced Raman scattering (SERS) substrate has been measured for the 1574 cm−1SERS mode. A value of 9.6 ± 1.7×10−14W was determined for the resonant component of the SECARS signal using 17.8 mW of 784.9 nm pump laser power and 7.1 mW of 895.5 nm Stokes laser power; the pump and Stokes lasers were polarized parallel to each other but perpendicular to the grooves of the diffraction grating in the spectrometer. The measured value of resonant component of the SECARS signal is in agreement with the calculated value of 9.3×10−14W using the measured value of 8.7 ± 0.5 cm−1for the SERS linewidth (full width at half-maximum) and the value of 5.7 ± 1.4×10−7for the product of the Raman cross section σSERSand the surface concentration Nsof the benzenethiol SAM. The xxxxcomponent of the resonant part of the third-order nonlinear optical susceptibility |3 | for the 1574 cm−1SERS mode has been determined to be 4.3 ± 1.1×10−5cm.g−1.s2. The SERS enhancement factor for the 1574 cm−1mode was determined to be 3.6 ± 0.9×107using the value of 1.8×1015molecules/cm2for Ns. [ABSTRACT FROM AUTHOR]

Raman line widths of neat benzenethiol and a self-assembled monolayer (SAM) of benzenethiol on a surface-enhanced Raman scattering (SERS) substrate have been measured using a mini spectrometer with a resolution (full width at half-maximum) of 3.3 ± 0.2 cm(-1). Values of 7.3 ± 0.7, 4.6 ± 0.6, 2.4 ± 0.6, 3.2 ± 0.5, 8.8 ± 0.9, and 11.0 ± 1.1 cm(-1) have been determined for the Raman line widths of the 414, 700, 1001, 1026, 1093, and 1584 cm(-1) modes of neat benzenethiol. Values of 13.3 ± 0.7, 9.1 ± 0.7, 5.1 ± 0.6, 5.9 ± 0.6, 13.3 ± 0.5, and 8.7 ± 0.5 cm(-1) have been determined for the SERS line widths of a benzenethiol SAM on a silver-coated SERS substrate for the corresponding frequency-shifted modes at 420, 691, 1000, 1023, 1072, and 1574 cm(-1). The line widths for the SERS modes at 420, 691, 1000, 1023, and 1072 cm(-1) are about a factor of two larger than those of the corresponding Raman modes. However, the line width of the SERS mode at 1574 cm(-1) is slightly smaller than the corresponding Raman mode at 1584 cm(-1).