Isaienko Oleksandr, Borguet Eric
Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania, USA.
Opt Express. 2012 Jan 2;20(1):547-61. doi: 10.1364/OE.20.000547.
We describe an ultrabroadband IR-visible sum-frequency (SF) setup that allows simultaneous acquisition of the entire vibrational spectrum of water molecules at mineral surfaces in the OH stretching region without ever tuning the IR laser pulses. Our newly developed 800-nm pumped noncollinear optical parametric amplifier (NOPA) generates broadband mid-IR pulses (~1800-3500 nm, or ~2900 - 6000 cm-1) with bandwidths >600 cm-1 at half-maximum at near 3500 cm-1. Using the ultra-broadband IR NOPA, we constructed a sum-frequency vibrational spectrometer that allowed the acquisition of spectra of the OH stretches of water at hydrophilic and hydrophobic silica surfaces, over the frequency range ~2900 - 3800 cm-1, within 60 s, much shorter than with scanning SFG spectrometers. The ultra-broadband SFG spectrometer reported here can be potentially applied to time-resolved measurements of kinetics at interfaces.
我们描述了一种超宽带红外 - 可见和频（SF）装置，该装置无需对红外激光脉冲进行调谐，就能在矿物表面的OH伸缩区域同时获取水分子的整个振动光谱。我们新开发的800纳米泵浦非共线光学参量放大器（NOPA）能产生宽带中红外脉冲（1800 - 3500纳米，或2900 - 6000厘米⁻¹），在接近3500厘米⁻¹处半高宽带宽>600厘米⁻¹。利用超宽带红外NOPA，我们构建了一台和频振动光谱仪，该光谱仪能在60秒内获取亲水性和疏水性二氧化硅表面水的OH伸缩光谱，频率范围约为~2900 - 3800厘米⁻¹，比扫描和频光谱仪所需时间短得多。这里报道的超宽带和频光谱仪有可能应用于界面动力学的时间分辨测量。
