- 2 cm-1 or 0.8 cm-1 linewidth
- Tuning range from 193 to 16000 nm
- Up to 0.7 mJ in VIS
- Up to 1 kHz repetition rate
- 2 cm-1 or 0.8 cm-1 linewidth
- Tuning range from 193 to 16000 nm
- Up to 0.7 mJ in VIS
- Up to 1 kHz repetition rate
Features & Applications
- 2 cm-1 or 0.8 cm-1 linewidth
- High brightness picosecond pulses at 50 Hz or at up to 1 kHz pulse repetition rate
- Nearly Fourier-transform limited linewidth
- Low divergence <2 mrad
- Hands-free wavelength tuning
- Tuning range from 193 nm to 16000 nm
- PC control using USB (RS232 is optional) and LabVIEW™ drivers
- Remote control via keypad
- Time resolved pump-probe spectroscopy
- Laser-induced fluorescence
- Infrared spectroscopy
- Nonlinear spectroscopy: vibrational-SFG, surface-SH, Z-scan, pump probe
- Other laser spectroscopy applications
PGx11 series optical parametric devices employ advanced design concepts in order to produce broadly tunable picosecond pulses with nearly Fourier-transform limited linewidth and low divergence. High brightness output beam makes the PGx11 series units an excellent choice for advanced spectroscopy applications.
Optical layout of PGx11 units consists of Synchronously pumped Optical Parametric Oscillator (SOPO) and Optical Parametric Amplifier (OPA). SOPO is pumped by a train of pulses at approx. 87 MHz pulse repetition rate. The output from SOPO consists of a train of pulses with excellent spatial and spectral characteristics, determined by the SOPO cavity parameters.
OPA is pumped by a single pulse temporally overlapped with SOPO output. After amplification at SOPO resonating wavelength, the PGx11 output represents a high intensity single pulse on top of a low-intensity train, while in all other spectral ranges (idler for PG411 and PG711, signal for PG511, also DFG stages) only a single high intensity pulse is present.
Three models designed for pumping by up to the 3rd harmonic of Nd:YAG laser are available.
Microprocessor based control system provides automatic positioning of relevant components, allowing hands free operation. Nonlinear crystals, diffraction grating and filters are rotated by ultra-precise stepper motors in microstepping mode, with excellent reproducibility. Precise nonlinear crystal temperature stabilization ensures long-term stability of generated wavelength and output power.
For customer convenience the system can be controlled through its USB type PC interface (RS232 is optional) with LabView™ drivers or a remote control pad. Both options allow easy control of system settings.
Available standard models are summarized in a Specifications table. Please inquire for custom-built versions.
|PG411||Model has a tuning range from 410 to 2300 nm and is optimized for providing highest pulse energy in the visible part of the spectrum. When combined with an optional Second Harmonic Generator (SHG) and Sum Frequency Generator (-DUV), it offers the widest possible tuning range – from 193 to 2300 nm.|
|PG511||Model has a tuning range from 2300 to 10000 nm. PG411 and PG511 models are designed to be pumped by PL2230 series lasers with a 50 Hz pulse repetition rate.|
|PG711||Model has 1 kHz pulse repetition rate and uses DPSS mode‑locked laser of the PL2210 series for pumping. When pumped with pulses of 90 ps duration, linewidths of less than 1 cm⁻¹ were measured in the spectral range up to 16 µm, which makes this device an excellent choice for time-resolved or nonlinear infrared spectroscopy.|
|OPA SPECIFICATIONS 1)|
|Output wavelength tuning range|
|SH, DUV||–||210–410 nm||193–410 nm||–|
|Signal||410–709 nm||–||1550–2020 nm|
|Idler||710–2300 nm||–||2250–3350 nm|
|DFG||–||2300–10000 nm||–||3350–16000 nm|
|DFG2 (up to 16000 nm)||–||inquire||–|
|Output pulse energy 2)|
|SH, DUV||–||100 µJ 3)||50 µJ 3)||–|
|Signal||700 µJ||–||500 µJ|
|Idler 4)||250 µJ||–||100 µJ|
|DFG||–||> 200 µJ at 3700 nm,|
> 40 μJ at 10000 nm
|–||20 µJ 5)|
|Max pulse repetition rate||50 Hz||1000 Hz|
|Linewidth||< 3 cm-1 6)||<2 cm-1||< 0.8 cm-1||< 1 cm-1|
|Linewidth Idler||< 5 cm-1 6)||–|
|Typical pulse duration 7)||~15 ps||~20 ps||~70 ps|
|SH, DUV||–||0.01 nm||–|
|Typical beam diameter 8)||~ 4 mm||~ 9 mm||~ 3 mm|
|Beam divergence 9)||< 2 mrad|
|Beam polarization 9)|
|PUMP LASER REQUIREMENTS|
|Recommended pump source||PL2231A + APL2100-TRAIN-H411||PL2231 + H500-APL2100-TRAIN||PL2211A TR|
|Min. pump energy or power 10)|
|at 1064 nm||–||2 mJ||(10 mJ)||5 mJ at 1 kHz|
|at 532 nm||–||5 mJ (8 mJ)||5 mJ at 1 kHz|
|at 355 nm||5 mJ (10 mJ)||–|
|Pulse duration 11)||30 ps||90 ps|
|Bream polarization at pump wavelength||vertical||horizontal|
|Beam size12)||7 mm||2.5 mm|
|Beam divergence||< 0.5 mrad|
|Beam profile||homogeneous, without hot spots|
|Size (W × L × H)||456×1026×244 mm||456×1226×244 mm||PL2231: 456×1026×244 mm|
H500-APL2100-TRAIN: 456×1026×244 mm
|456 × 1026 × 244 mm|
|Room temperature||15 – 30 °C|
|Room temperature stability||± 2 °C|
|Power requirements||100 – 240 V single phase, 47 – 63 Hz|
|Power consumption||< 300 W|
- Due to continuous improvement, all specifications are subject to change without notice. Parameters marked typical are not specifications. They are indications of typical performance and will vary with each unit we manufacture. Unless stated otherwise, all specifications are measured at 450 nm for PG411 units, 800 nm for PG511 units, and 1620 nm for PG711 units and for basic system without options.
- Pulse energies are specified at selected wavelengths. See typical tuning curves for pulse energies at other wavelengths.
- Measured at 280 nm for SH and 200 nm for DUV.
- Measured at 1000 nm for PG411 units, 1620 nm for PG511, and 3000 nm for PG711 units.
- Measured at 10000 nm.
- Linewidth for signal (409 – 710 nm) <3 cm-1, linewidth for idler and SH-DUV (710 – 2300 nm and 193 – 409 nm) <5 cm-1.
- Estimated FWHM assuming pump pulse duration 30 ps at 1064 nm for PG411 and PG511 units, and 90 ps at 1064 nm for PG711 units.
- Beam diameter is measured at 1/e² level and can vary depending on the pump pulse energy.
- Full angle measured at FWHM level.
- The first number represents pulse train energy or power, while the value in brackets represents single pulse energy.
- At FWHM level. Inquire for other available pulse duration options.
- Beam diameter measured at 1/e² level.
Note: Laser must be connected to the mains electricity all the time. If there will be no mains electricity for longer that 1 hour then laser (system) needs warm up for a few hours before switching on.
Note: The energy tuning curves are affected by air absorption due narrow linewidth. These pictures present pulse energies where air absorption is negligible.
Optical Layouts & Drawings
Structure Determination of Hen Egg-White Lysozyme Aggregates Adsorbed to Lipid/Water and Air/Water Interfaces
We use vibrational sum-frequency generation (VSFG) spectroscopy to study the structure of hen egg-white lysozyme (HEWL) aggregates adsorbed to DOPG/D2O and air/D2O interfaces. We find that aggregates with a parallel and antiparallel β-sheet structure together with smaller unordered aggregates and a denaturated protein are adsorbed to both interfaces. We demonstrate that to retrieve this information, fitting of the VSFG spectra is essential. The number of bands contributing to the VSFG spectrum might be misinterpreted, due to interference between peaks with opposite orientation and a nonresonant background. Our study identified hydrophobicity as the main driving force for adsorption to the air/D2O interface. Adsorption to the DOPG/D2O interface is also influenced by hydrophobic interaction; however, electrostatic interaction between the charged protein’s groups and the lipid’s headgroups has the most significant effect on the adsorption. We find that the intensity of the VSFG spectrum at the DOPG/D2O interface is strongly enhanced by varying the pH of the solution. We show that this change is not due to a change of lysozyme’s and its aggregates’ charge but due to dipole reorientation at the DOPG/D2O interface. This finding suggests that extra care must be taken when interpreting the VSFG spectrum of proteins adsorbed at the lipid/water interface.
Vibrational Relaxation Lifetime of a Physisorbed Molecule at a Metal Surface
Previous measurements of vibrational relaxation lifetimes for molecules adsorbed at metal surfaces yielded values of 1–3 ps; however, only chemisorbed molecules have been studied. We report the first measurements of the vibrational relaxation lifetime of a molecule physisorbed to a metal surface. For CO(v=1) adsorbed on Au(111) at 35 K the vibrational lifetime of the excited stretching mode is 49±3 ps. The long lifetime seen here is likely to be a general feature of physisorption, which involves weaker electronic coupling between the adsorbate and the solid due to bonding at larger distances.
Ultra-sensitive mid-infrared emission spectrometer with sub-ns temporal resolution
We evaluate the performance of a mid-infrared emission spectrometer operating at wavelengths between 1.5 and 6 μm based on an amorphous tungsten silicide (a-WSi) superconducting nanowire single-photon detector (SNSPD). We performed laser induced fluorescence spectroscopy of surface adsorbates with sub-monolayer sensitivity and sub-nanosecond temporal resolution. We discuss possible future improvements of the SNSPD-based infrared emission spectrometer and its potential applications in molecular science.
Mid-infrared, super-flat, supercontinuum generation covering the 2–5 μm spectral band using a fluoroindate fibre pumped with picosecond pulses
Broadband, mid-infrared supercontinuum generation in a step-index fluoroindate fibre is reported. By using ~70-picosecond laser pulses at 2.02 μm, provided by an optical parametric generator, a wide spectrum with a cut-off wavelength at 5.25 μm and a 5-dB bandwidth covering the entire 2–5 μm spectral interval has been demonstrated for the first time. The behaviour of the supercontinuum was investigated by changing the peak power and the wavelength of the pump pulses. This allowed the optimal pumping conditions to be determined for the nonlinear medium that was used. The optical damage threshold for the fluoroindate fibre was experimentally found to be ~200 GW/cm2.
Detection of Disease Markers in Human Breath with Laser Absorption Spectroscopy
Number of trace compounds (called biomarkers), which occur in human breath, provide an information about individual feature of the body, as well as on the state of its health. In this paper we present the results of experiments about detection of certain biomarkers using laser absorption spectroscopy methods of high sensitivity. For NO, OCS, C2H6, NH3, CH4, CO and CO(CH3)2 an analysis of the absorption spectra was performed. The influence of interferents contained in exhaled air was considered. Optimal wavelengths of the detection were found and the solutions of the sensors, as well as the obtained results were presented. For majority of the compounds mentioned above the detection limits applicable for medicine were achieved. The experiments showed that the selected optoelectronic techniques can be applied for screening devices providing early diseases detection.
Retrieval of complex χ(2) parts for quantitative analysis of sum-frequency generation intensity spectra
Vibrational sum-frequency generation (SFG) spectroscopy has become an established technique for in situ surface analysis. While spectral recording procedures and hardware have been optimized, unique data analysis routines have yet to be established. The SFG intensity is related to probing geometries and properties of the system under investigation such as the absolute square of the second-order susceptibility |χ(2)|2 . A conventional SFG intensity measurement does not grant access to the complex parts of χ(2) unless further assumptions have been made. It is therefore difficult, sometimes impossible, to establish a unique fitting solution for SFG intensity spectra. Recently, interferometric phase-sensitive SFG or heterodyne detection methods have been introduced to measure real and imaginary parts of χ(2) experimentally. Here, we demonstrate that iterative phase-matching between complex spectra retrieved from maximum entropy method analysis and fitting of intensity SFG spectra (iMEMfit) leads to a unique solution for the complex parts of χ(2) and enables quantitative analysis of SFG intensity spectra. A comparison between complex parts retrieved by iMEMfit applied to intensity spectra and phase sensitive experimental data shows excellent agreement between the two methods.
Unified treatment and measurement of the spectral resolution and temporal effects in frequency-resolved sum-frequency generation vibrational spectroscopy (SFG-VS)
The lack of understanding of the temporal effects and the restricted ability to control experimental conditions in order to obtain intrinsic spectral lineshapes in surface sum-frequency generation vibrational spectroscopy (SFG-VS) have limited its applications in surface and interfacial studies. The emergence of high-resolution broadband sum-frequency generation vibrational spectroscopy (HR-BB-SFG-VS) with sub-wavenumber resolution [Velarde et al., J. Chem. Phys., 2011, 135, 241102] offers new opportunities for obtaining and understanding the spectral lineshapes and temporal effects in SFG-VS. Particularly, the high accuracy of the HR-BB-SFG-VS experimental lineshape provides detailed information on the complex coherent vibrational dynamics through direct spectral measurements. Here we present a unified formalism for the theoretical and experimental routes for obtaining an accurate lineshape of the SFG response. Then, we present a detailed analysis of a cholesterol monolayer at the air/water interface with higher and lower resolution SFG spectra along with their temporal response. With higher spectral resolution and accurate vibrational spectral lineshapes, it is shown that the parameters of the experimental SFG spectra can be used both to understand and to quantitatively reproduce the temporal effects in lower resolution SFG measurements. This perspective provides not only a unified picture but also a novel experimental approach to measuring and understanding the frequency-domain and time-domain SFG response of a complex molecular interface.
Investigating buried polymer interfaces using sum frequency generation vibrational spectroscopy
This paper reviews recent progress in the studies of buried polymer interfaces using sum frequency generation (SFG) vibrational spectroscopy. Both buried solid/liquid and solid/solid interfaces involving polymeric materials are discussed. SFG studies of polymer/water interfaces show that different polymers exhibit varied surface restructuring behavior in water, indicating the importance of probing polymer/water interfaces in situ. SFG has also been applied to the investigation of interfaces between polymers and other liquids. It has been found that molecular interactions at such polymer/liquid interfaces dictate interfacial polymer structures. The molecular structures of silane molecules, which are widely used as adhesion promoters, have been investigated using SFG at buried polymer/silane and polymer/polymer interfaces, providing molecularlevel understanding of polymer adhesion promotion. The molecular structures of polymer/solid interfaces have been examined using SFG with several different experimental geometries. These results have provided molecularlevel information about polymer friction, adhesion, interfacial chemical reactions, interfacial electronic properties, and the structure of layerbylayer deposited polymers. Such research has demonstrated that SFG is a powerful tool to probe buried interfaces involving polymeric materials, which are difficult to study by conventional surface sensitive analytical techniques.