Sum Frequency Generation Vibrational Spectroscopy Sensitive and selective to the orientation of molecules in the surface layer Picosecond scanning Femtosecond broadband Spectral resolution < 3 cm-1

LASER SPECTROSCOPY SYSTEMS Sum Frequency Generation Vibrational Spectroscopy (SFG-VS) is powerful and versatile method for in-situ investigation of surfaces and interfaces. In SFG-VS experiment a pulsed tunable infrared IR (wR) laser beam is mixed with a visible VIS (wvis) beam to produce an output at the sum frequency (wSFG = wIR + wVIS). SFG is second order nonlinear process, which is allowed only in media without inversion symmetry. At surfaces or interfaces inversion symmetry is necessarily broken, that makes SFG highly surface specific. As the IR wavelength is scanned, active vibrational...

LASER SPECTROSCOPY SYSTEMS Narrowband picosecond scanning and broadband femtosecond SFG spectrometer VIS Narrowband picosecond scanning SFG spectrometer Broadband femtosecond SFG spectrometer In order to obtain SFG spectrum during measurement wavelength of narrowband mid-IR pulse is changed point‑by-point throughout the range of interest. Narrowband SFG signal is recorded by the time-gated photomultiplier. Energy of each mid-IR, VIS and SFG pulse is measured. After the measurement, the SFG spectrum can be normalised according to IR and VIS energy. Spectral resolution is determined by the bandwidth...

LASER SPECTROSCOPY SYSTEMS Features and design of the picosecond scanning SFG spectrometer SYSTEM COMPONENTS ▶ Picosecond mode-locked Nd:YAG laser and optical parametric generator in one unit Spectroscopy module with: – PMT based signal detectors – Data acquisition system – Dedicated LabView® software package for system control The SFG spectrometer developed by Ekspla engineers is a nonlinear spectrometry instrument, convenient for everyday use. Ekspla manufactures SFG spectrometers, which are used by chemists, biologists, material scientists, and physicists. The spectrometer has many features...

LASER SPECTROSCOPY SYSTEMS S P E C T R O S C O P Y M O D U L E , S A M P L E C O M PA R T M E N T A large sample compartment can be customised and enables the use of various extensions and additional instruments for simultaneous control of the sample conditions, including a Langmuir-Blodgett trough for air/water and lipid/air interface studies, temperature and humidity-controlled cells, and other instruments. Standard layout of the vertically-arranged sample compartment of the SFG spectrometer SAFETY OF THE SFG SPECTROMETER The spectrometer is safe to use: all high energy pulsed beams are enclosed....

LASER SPECTROSCOPY SYSTEMS SPECTRA EXAMPLES SFG spectra of monoolein surface, 1 cm-1 scan step, 200 acquisitions per step DOUBLE RESONANCE MODEL This two-dimensional spectroscopy is more selective than single resonant SFG. Double resonant SFG allows investigation of vibrational mode coupling to electron states at a surface. Double resonance enables the use of another wavelength for VIS beam Water-air interface spectra, 200 acquisitions per step Picosecond scanning SFG spectrometer Modifications and Options Both IR and VIS wavelengths are tunable in Double resonance SFG spectrometer model. if...

LASER SPECTROSCOPY SYSTEMS SFG SPECTROMETERSPHASE-SENSITIVE SFG SPECTROMETERPhase sensitive measurements A phase sensitive spectrometer allows the measurement the phase of nonlinear susceptibility x(2). Reference and test samples are used and the SFG phase difference between them is scanned. The real and imaginary parts of second order susceptibility are calculated from the experimental results. Such an approach enables the unambiguous determination of the orientation of molecular groups at the interface. In conventional SFG-VS intensity of SF signal is measured. It is proportional to the square...

LASER SPECTROSCOPY SYSTEMS PHASE SENSITIVE SFG + CLASSIC SFG SPECTROMETER IN ONE UNIT Interference measurements of SFG signals from reference sample and the investigated sample for Phase-sensitive configuration. Switchable setup. Phase Sensitive / “Classic” Top configuration. Switch: VIS beam manual. IR mirror mount is motorised, lens positioning stage is manual. Path length to the sample is same in all configuration Motorised polarisation control. VIS beam 532 nm. IR 2.3 – up to 16 µm. “Classic” configuration OPTIONS Spectrometer has "Classic" and "Phase-sensitive" properties: ▶ ▶ Easy switching...

LASER SPECTROSCOPY SYSTEMS SFG SPECTROMETERS SFG Spectrometer polarisation control options SIMULTANEOUS MEASUREMENT OF S AND P POLARISATION S and P polarisation of the SFG signal are detected during the same measurement in the dual polarisation detection system. Classic detection system COIR COvis (Osfg Gian prism Dual detection system SFG signal to detector 2 Gian prism MOTORIZED POLARISATION CONTROL OF SFG, VIS, IR The SFG spectrometer has a motorized polarisation switch for the IR, VIS, and the generated SFG light beams. The automatic change of polarisation and energy attenuation makes it...

LASER SPECTROSCOPY SYSTEMS Version SFG Classic SFG Double Resonance SFG Phase Sensitive For standard specifications please check the brochure of particular model. PHYSICAL DIMENSIONS (FOOTPRINT) 1 Due to continuous improvement, all specifications are subject to change without advance notice. 2) Laser is optimised for pumping parametrical generator, maximum output energy may be different than specified for stand alone application. REV. 250617 SAVANORIU AV. 237, LT-02300 VILNIUS, LITHUANIA TEL +370 5 2649629 E-MAIL [email protected] WWW.EKSPLA.COM &EKSPLA 9

LASER SPECTROSCOPY SYSTEMS Features and design of the broadband femtosecond SFG spectrometer bandwidth (150 – 450 cm-1) mid-IR radiation can be continuously tuned in a spectral range from 2.5 up to 10 μm, providing from 0.5 to 12 μJ close to energy transform-limited pulses for the IR channel. The VIS channel implementation depends on the system configuration. In a standard setup, a part of laser output radiation is frequency doubled (515 nm) ~20 µJ and then spectrally filtered to produce <8 cm-1 bandwidth pulses. High resolution version consists of optically synchronised femtosecond and picosecond...