NT340 series

High Energy Broadly Tunable Lasers
  • Integrated OPO system
  • High energy
  • Ultrabroad tuning range from 192 to 4400 nm
  • Up to 50 mJ in VIS
  • Up to 20 Hz repetition rate
  • Integrated OPO system
  • High energy
  • Ultrabroad tuning range from 192 to 4400 nm
  • Up to 50 mJ in VIS
  • Up to 20 Hz repetition rate

Features & Applications


  • Hands-free no gap wavelength tuning from 192 to 4400 nm
  • Up to 50 mJ pulse energy in visible spectral range
  • Up to 10 mJ pulse energy in UV spectral range
  • Up to 15 mJ pulse energy in MIR spectral range
  • 3 – 5 ns pulse duration
  • Up to 20 Hz pulse repetition rate
  • Remote control via key pad or PC
  • Optional separate shared output port for 532/1064 nm beam (separate output port for the 355 nm beam is standard)
  • OPO pump energy monitoring
  • Hermetically sealed oscillator cavity protects non-linear crystals from dust and humidity


  • Laser-induced fluorescence
  • Flash photolysis
  • Photobiology
  • Remote sensing
  • Time-resolved spectroscopy
  • Non-linear spectroscopy


  • The system is widely tunable 192 – 2600 nm and delivers high pulse energy (up to 50 mJ) that allows the investigation of an extensive range of materials
  • Up to 18 μm customization possibility enables studies of IR vibrations of molecules
  • Narrow linewidth (down to 3 cm⁻¹) and superior tuning resolution (1 – 2 cm⁻¹) allows recording of high quality spectra
  • Flashlamps replacement without misalignment of the laser cavity saves on maintenance costs
  • High integration level saves valuable space in the laboratory
  • In-house design and manufacturing of complete systems, including pump lasers, guarantees on-time warranty and post warranty services and spares supply
  • Variety of control interfaces: USB, RS232, LAN and WLAN ensures easy control and integration with other equipment
  • Attenuator and fiber coupling options facilitate incorporation of NT340 systems into various experimental environments


The NT340 series tunable wavelength nanosecond laser seamlessly integrates the nanosecond optical parametric oscillator and the Nd:YAG Q-switched nanosecond laser – all in a compact housing.
The main system features are: hands-free wavelength tuning from UV to IR, high conversion efficiency, optional fiber-coupled output and separate output port for pump laser beam.

NT340 has a linewidth of less than 5 cm⁻¹, which is ideal for many spectroscopic applications.

The laser is designed for convenient use. It can be controlled from remote keypad or PC using LabView™ drivers that are supplied with the system. The remote keypad features a backlit display that is easy to read even through laser safety googles. The OPO pump energy monitoring system helps to control pump laser parameters. Replacement of laser flashlamps can be done without misalignment of the laser cavity and/or deterioration of laser performance.

Tuning range extensions

-SHSecond harmonic generator for 210 – 410 nm range
-SFSum-frequency generator for 300 – 410 nm range with high pulse energy
-SH/SFCombined option for highest pulse energy in 210 – 410 nm range
-DUVDeep UV option for 192 – 210 nm range
-MIRMid infrared option for 2500 – 4400 nm range output

Accessories and Options

-FCFiber coupled output in 350 – 2000 nm range
-ATTN/FCFiber coupled attenuator
-H, -2HSeparate shared output port for Nd:YAG pump laser harmonics (532 or 1064 nm wavelengths)
-AWAir cooled power supply


OPO 1)
Wavelength range 2)
    Signal 410 – 710 nm 3)
    Idler 710 – 2600 nm
    SH generator (optional) 210 – 410 nm
    SH/SF generator (optional)210 – 410 nm
    DUV generator (optional)192 – 210 nm
    MIR generator (optional)2500 – 4400 nm
Output pulse energy
    OPO 4)30 mJ50 mJ
    SH generator (optional) 5)4 mJ6.5 mJ
    SH/SF generator (optional) 6)6 mJ10 mJ
    DUV generator (optional) 7)0.6 mJ1 mJ
    MIR generator (optional) 8)15 mJ
Linewidth<5 cm-1 9)
Tuning resolution 10)
    Signal (410 – 710 nm)1 cm⁻¹
    Idler (710 – 2600 nm) 1 cm⁻¹
    SH/SF/DUV beam (192 – 410 nm) 2 cm⁻¹
    MIR (2500 – 4400 nm) 1 cm⁻¹
Pulse duration 11)3 – 5 ns
Typical beam diameter 12)5 mm7 mm
Typical beam divergence 13)< 2 mrad
    Signal beamhorizontal
    Idler beamvertical
    SH/SF beamhorizontal
    DUV beamvertical
    MIR beamhorizontal
Pump wavelength355 nm
Typical pump pulse energy100 mJ150 mJ
Pulse duration4 – 7 ns
Beam qualityHat-top in near field, without hot spots
Beam divergence< 0.6 mrad
Pulse energy stability (StdDev)< 3.5 %
Pulse repetition rate10 or 20 Hz10 Hz
Unit size (W × L × H) 15)456 × 821× 270 mm
Power supply size (W × L × H)330 × 490 × 585 mm
Umbilical length2.5 m
Water consumption (max 20 °C) 16)< 10 l/min
Room temperature18 – 27 °C
Relative humidity20 – 80 % (non-condensing)
Mains voltage200 – 240 VAC, single phase, 50/60 Hz
Power consumption< 1.5 kVA
  1. Due to continuous improvement, all specifications are subject to change. Parameters marked typical are illustrative; they are indications of typical performance and will vary with each unit we manufacture. Unless stated otherwise, all specifications are measured at 450 nm and for basic system without options.
  2. Hands-free tuning range is from 192 nm to 4400 nm. MIR option is not compatible with SF and DUV option. Inquire for custom IR option with tuning up to 18 µm.
  3. Tuning range extension to 400 – 709 nm is optional.
  4. Measured at 430 nm. See tuning curves for typical outputs at other wavelengths.
  5. Measured at 260 nm. See tuning curves for typical outputs at other wavelengths.
  6. Measured at 340 nm. SF generator is optimized for maximum output in 300 – 410 nm range. See tuning curves for typical outputs at other wavelengths.
  7. Measured at 200 nm. See tuning curves for typical outputs at other wavelengths.
  8. Measured at 3000 nm. See tuning curves for typical outputs at other wavelengths.
  9. Linewidth is <8 cm⁻¹ for 210 – 409 nm, 2500 – 4400 nm ranges.
  10. When wavelength is controlled from PC. When wavelength is controlled from keypad, tuning resolution is 0.1 nm for signal, 1 nm for idler, MIR and 0.05 nm for SH, SF and DUV.
  11. FWHM measured with photodiode featuring 1 ns rise time and 300 MHz bandwidth oscilloscope.
  12. Beam diameter is measured at 450 nm at the FWHM level. It is approximate and can vary depending on the pump pulse energy and wavelength.
  13. Full angle measured at the FWHM level at 450 nm, < 5 mrad at 3000 nm with MIR option.
  14. Separate output port for the 355 nm beam is standard. Outputs for 1064 nm and 532 nm beams are optional. Laser output will be optimised for the best OPO operation and specifications may vary with each unit we manufacture.
  15. Length from 821 to 1220 mm depending on configuration.
  16. Air cooled power supply is available as an option.

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.

Performance & Drawings


Found total :
10 articles, 10 selected
Application selected :
All Applications
All Applications
Scientific Applications
Photolysis – breaking down of a chemical compound by photons
Laser Spectroscopy
Absorption Spectroscopy
Luminescence Spectroscopy
Gas-phase Ion Luminescence

Luminescence spectroscopy of chalcogen substituted rhodamine cations in vacuo

Related applications:  Laser Spectroscopy Gas-phase Ion Luminescence

Authors:  M.H. Stockett, Ch. Kjær, M.K. Linder, M.R. Detty, S.B. Nielsen

Intrinsic optical properties of several rhodamine cations were probed by measuring their dispersed fluorescence spectra in vacuo. Three different rhodamine structures were investigated, each with four different chalcogen heteroatoms. Fluorescence band maxima were blue-shifted by between 0.15 and 0.20 eV (1200–1600 cm−1) relative to previous solution-phase measurements. Trends in emission wavelengths and fluorescence quantum yields previously measured in solution are generally reproduced in the gas phase, confirming the intrinsic nature of these effects. One important exception is gas-phase brightness of the Texas Red analogues, which is significantly higher than the other rhodamine structures studied, despite having similar fluorescence quantum yields in solution. These results expand the library of fluorophores for which gas-phase photophysical data is available, and will aid in the design of experiments utilizing gas-phase structural biology methods such as Förster resonance energy transfer.

Published: 2017.   Source: Photochem. Photobiol. Sci., 2017,16, 779-784

Sibling rivalry: intrinsic luminescence from two xanthene dye monoanions, resorufin and fluorescein, provides evidence for excited-state proton transfer in the latter

Related applications:  Laser Spectroscopy Gas-phase Ion Luminescence

Authors:  Ch. Kjær, S.B. Nielsen, M.H. Stockett

While the emission spectrum of fluorescein monoanions isolated in vacuo displays a broad and featureless band, that of resorufin, also belonging to the xanthene family, has a sharp band maximum, clear vibronic structure, and experiences a small Stokes shift. Excited-state proton transfer in fluorescein can account for the differences.

Published: 2017.   Source: Phys. Chem. Chem. Phys., 2017,19, 24440-24444

Luminescence Spectroscopy of Rhodamine Homodimer Dications in Vacuo Reveals Strong Dye‐Dye Interactions

Related applications:  Laser Spectroscopy Gas-phase Ion Luminescence

Authors:  Ch. Kjær, H. Lissau, N.K.G. Salinas, A.Ø. Madsen, M.H. Stockett, F.E. Storm, T.H. Hansen, J.U. Andersen, B.W. Laursen, K.V. Mikkelsen, M.B. Nielsen, S.B. Nielsen

Being alone or together makes a difference for the photophysics of dyes but for ionic dyes it is difficult to quantify the interactions due to solvent screening and nearby counter ions. Gas‐phase luminescence experiments are desirable and now possible based on recent developments in mass spectrometry. Here we present results on tailor‐made rhodamine homodimers where two dye cations are separated by methylene linkers, (CH2)n. In solution the fluorescence is almost identical to that from the monomer whereas the emission from bare cation dimers redshifts with decreasing n. In the absence of screening, the electric field from the charge on one dye is strong enough to polarize the other dye, both in the ground state and in the excited state. An electrostatic model based on symmetric dye responses (equal induced‐dipole moments in ground state) captures the underlying physics and demonstrates interaction even at large distances. Our results have possible implications for gas‐phase Förster Resonance Energy Transfer.

Published: 2018.   Source: ChemPhysChem, Vol. 20 (4), p. 533-537, 2019

Gas-phase Ion Spectroscopy of Flexible and Nonflexible Nitrophenolates: Effect of Locking the Two Phenyl Units in 4’-nitro-[1,1’-biphenyl]-4-olate by a Bridging Atom

Related applications:  Laser Spectroscopy Gas-phase Ion Luminescence

Authors:  B.M. Pedersen, S.B. Nielsen

Nitrophenolates (NPs) are molecular anions that can undergo charge-transfer (CT) transitions determined by the degree of electron delocalization between the phenolate oxygen (donor group) and the nitro group (acceptor). Here we have studied four different NPs: 4’-nitro-[1,1’-biphenyl]-4-olate (1), 7-nitro-9H-carbazol-2-olate (NH linker, 2), 7-nitrodibenzo[b,d]furan-3-olate (oxygen linker, 3), and 7-nitrodibenzo[b,d]thiophen-3-olate (sulphur linker, 4), and recorded their electronic absorption spectra when isolated in vacuo to determine the effect of locking the biphenyl spacer group between the donor and acceptor on transition energies. Absorption was identified from ion dissociation (action spectroscopy) using a homebuilt setup (sector mass spectrometer combined with pulsed laser). We find that the absorption is broad in the visible region for all four NPs with significant vibronic features. The lowest energy peak is at 601 ± 4 nm, 606 ± 4 nm, 615 ± 4 nm, and 620 ± 4 nm, for 3, 4, 2, and 1, respectively. NP 1 is flexible, and its lowest energy structure is nonplanar while the other three NPs are planar according to density functional theory calculations. Hence in the case of 1 the electronic transition has a higher degree of CT than for the other three, accounting for its absorption furthest to the red. Our work demonstrates that oxygen and sulphur are best at conveying the electronic coupling between the donor and acceptor sites as 3 and 4 absorb furthest to the blue (i.e., the degree of CT is lowest for these two NPs). Based on the average spacing between the peaks in the vibrational progressions, coupling occurs to skeleton vibrational modes with frequencies of 649 ± 69 cm-1 (3), 655 ± 49 cm-1 (4), and 697 ± 52 cm-1 (2).

Published: 2018.   Source: Journal of Self-Assembly and Molecular Electronics, Vol. 6_1, 1–12.

Photodissociation of Sodium Iodide Clusters Doped with Small Hydrocarbons

Related applications:  Photolysis

Authors:  N. K. Bersenkowitsch, Dr. M. Ončák, J. Heller, Dr. Ch. van der Linde, Prof. Dr. M. K. Beyer

Marine aerosols consist of a variety of compounds and play an important role in many atmospheric processes. In the present study, sodium iodide clusters with their simple isotope pattern serve as model systems for laboratory studies to investigate the role of iodide in the photochemical processing of sea‐salt aerosols. Salt clusters doped with camphor, formate and pyruvate are studied in a Fourier transform ion cyclotron resonance mass spectrometer (FT‐ICR MS) coupled to a tunable laser system in both UV and IR range. The analysis is supported by ab initio calculations of absorption spectra and energetics of dissociative channels. We provide quantitative analysis of IRMPD measurements by reconstructing one‐photon spectra and comparing them with the calculated ones. While neutral camphor is adsorbed on the cluster surface, the formate and pyruvate ions replace an iodide ion. The photodissociation spectra revealed several wavelength‐specific fragmentation pathways, including the carbon dioxide radical anion formed by photolysis of pyruvate. Camphor and pyruvate doped clusters absorb in the spectral region above 290 nm, which is relevant for tropospheric photochemistry, leading to internal conversion followed by intramolecular vibrational redistribution, which leads to decomposition of the cluster. Potential photodissociation products of pyruvate in the actinic region may be formed with a cross section of <2×10−20 cm2, determined by the experimental noise level.

Published: 2018.   Source: Chem. Eur.J. 2018, 24,12433 –12443

Photochemistry and spectroscopy of small hydrated magnesium clusters Mg+(H2O)n, n = 1–5

Related applications:  Photolysis

Authors:  M. Ončák, T. Taxer, E. Barwa, Ch. van der Linde, M. K. Beyer

Hydrated singly charged magnesium ions Mg+(H2O)n, n ≤ 5, in the gas phase are ideal model systems to study photochemical hydrogen evolution since atomic hydrogen is formed over a wide range of wavelengths, with a strong cluster size dependence. Mass selected clusters are stored in the cell of an Fourier transform ion cyclotron resonance mass spectrometer at a temperature of 130 K for several seconds, which allows thermal equilibration via blackbody radiation. Tunable laser light is used for photodissociation. Strong transitions to D1–3 states (correlating with the 3s-3px,y,z transitions of Mg+) are observed for all cluster sizes, as well as a second absorption band at 4–5 eV for n = 3-5. Due to the lifted degeneracy of the 3px,y,z energy levels of Mg+, the absorptions are broad and red shifted with increasing coordination number of the Mg+ center, from 4.5 eV for n = 1 to 1.8 eV for n = 5. In all cases, H atom formation is the dominant photochemical reaction channel. Quantum chemical calculations using the full range of methods for excited state calculations reproduce the experimental spectra and explain all observed features. In particular, they show that H atom formation occurs in excited states, where the potential energy surface becomes repulsive along the O⋯H coordinate at relatively small distances. The loss of H2O, although thermochemically favorable, is a minor channel because, at least for the clusters n = 1-3, the conical intersection through which the system could relax to the electronic ground state is too high in energy. In some absorption bands, sequential absorption of multiple photons is required for photodissociation. For n = 1, these multiphoton spectra can be modeled on the basis of quantum chemical calculations.

Published: 2018.   Source: J. Chem. Phys. 149, 044309 (2018)

Electronic spectroscopy and nanocalorimetry of hydrated magnesium ions [Mg(H2O)n]+, n = 20–70: spontaneous formation of a hydrated electron?

Related applications:  Photolysis

Authors:  T. Taxer, M. Ončák, E. Barwa, Ch. van der Lindea, M. K. Beyer

Hydrated singly charged magnesium ions [Mg(H2O)n]+ are thought to consist of an Mg2+ ion and a hydrated electron for n > 15. This idea is based on mass spectra, which exhibit a transition from [MgOH(H2O)n−1]+ to [Mg(H2O)n]+ around n = 15–22, black-body infrared radiative dissociation, and quantum chemical calculations. Here, we present photodissociation spectra of size-selected [Mg(H2O)n]+ in the range of n = 20–70 measured for photon energies of 1.0–5.0 eV. The spectra exhibit a broad absorption from 1.4 to 3.2 eV, with two local maxima around 1.7–1.8 eV and 2.1–2.5 eV, depending on cluster size. The spectra shift slowly from n = 20 to n = 50, but no significant change is observed for n = 50–70. Quantum chemical modeling of the spectra yields several candidates for the observed absorptions, including five- and six-fold coordinated Mg2+ with a hydrated electron in its immediate vicinity, as well as a solvent-separated Mg2+/e pair. The photochemical behavior resembles that of the hydrated electron, with barrierless interconversion into the ground state following the excitation.

Published: 2018.   Source: Faraday Discuss., 2019, Advance Article

Photodissociation spectroscopy of protonated leucine enkephalin

Related applications:  Photolysis

Authors:  A. Herburger, Ch. van der Linde, M. K. Beyer

Protonated leucine enkephalin (YGGFL) was studied by ultraviolet photodissociation (UVPD) from 225 to 300 nm utilizing an optical parametric oscillator tunable wavelength laser system (OPO). Fragments were identified by absolute mass measurement in a 9.4 T Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS). Bond cleavage was preferred in the vicinity of the two aromatic residues, resulting in high ion abundances for a4, a1, b3, y2 and y1 fragments. a, b and y ions dominated the mass spectrum, and full sequence coverage was achieved for those types. Photodissociation was most effective at the short wavelength end of the studied range, which is assigned to the onset of the La π–π* transition of the tyrosine chromophore, but worked well also at the Lb π–π* chromophore absorption maxima in the 35 000–39 000 cm−1 region. Several side-chain and internal fragments were observed. H atom loss is observed only above 41 000 cm−1, consistent with the requirement of a curve crossing to a repulsive 1πσ* state. It is suggested that the photochemically generated mobile H atom plays a role in further backbone cleavages, similar to the mechanism for electron capture dissociation. The b4 fragment is most intense at the Lb chromophore absorptions, undergoing additional fragmentation at higher photon energies. The high resolution of the FT-ICR MS revealed that out of all x and z-type fragments only x3 and x4 were formed, with low intensity. Other previously reported x- and z-fragments were re-assigned to internal fragments, based on exact mass measurement.

Published: 2017.   Source: Phys. Chem. Chem. Phys., 2017,19, 10786-10795

Luminescence spectroscopy of oxazine dye cations isolated in vacuo

Related applications:  Luminescence Spectroscopy

Authors:  Ch. Kjær, S. B. Nielsen

Here we report gas-phase action and luminescence spectra of cationic dyes derived from oxazine: cresyl violet (CV+), oxazine 170 (Ox-170+), nile blue (NB+), darrow red (DR+), oxazine 1 (Ox-1+), oxazine 4 (Ox-4+), and brilliant cresyl blue (BCB+). The first four have a benzofused structure, which results in asymmetric charge distributions along the long axis. The positive charge is also asymmetrically distributed in BCB+ while Ox-1+ and Ox-4+ are symmetric. As the ions are isolated in vacuo, there are no interactions with solvent molecules or counter ions, and the effect of chemical modifications is therefore more easily revealed than from solution-phase experiments. The transition energy decreases in the order: DR+ > CV+ > Ox-4+ > Ox-170+ > BCB+ > Ox-1+ > NB+, and the fluorescence from BCB+ is less than from the others. We discuss the results based on electron delocalisation, degree of charge-transfer character, rigidity of the chromophore structure, and substituents.

Published: 2019.   Source: Phys. Chem. Chem. Phys., 2019,21, 4600-4605

A cylindrical quadrupole ion trap in combination with an electrospray ion source for gas-phase luminescence and absorption spectroscopy

Related applications:  Absorption Spectroscopy Luminescence Spectroscopy

Authors:  M. H. Stockett, J. Houmøller, K. Støchkel, A. Svendsen, S. B. Nielsen

A relatively simple setup for collection and detection of light emitted from isolated photo-excited molecular ions has been constructed. It benefits from a high collection efficiency of photons, which is accomplished by using a cylindrical ion trap where one end-cap electrode is a mesh grid combined with an aspheric condenser lens. The geometry permits nearly 10% of the emitted light to be collected and, after transmission losses, approximately 5% to be delivered to the entrance of a grating spectrometer equipped with a detector array. The high collection efficiency enables the use of pulsed tunable lasers with low repetition rates (e.g., 20 Hz) instead of continuous wave (cw) lasers or very high repetition rate (e.g., MHz) lasers that are typically used as light sources for gas-phase fluorescence experiments on molecular ions. A hole has been drilled in the cylinder electrode so that a light pulse can interact with the ion cloud in the center of the trap. Simulations indicate that these modifications to the trap do not significantly affect the storage capability and the overall shape of the ion cloud. The overlap between the ion cloud and the laser light is basically 100%, and experimentally >50% of negatively charged chromophore ions are routinely photodepleted. The performance of the setup is illustrated based on fluorescence spectra of several laser dyes, and the quality of these spectra is comparable to those reported by other groups. Finally, by replacing the optical system with a channeltron detector, we demonstrate that the setup can also be used for gas-phase action spectroscopy where either depletion or fragmentation is monitored to provide an indirect measurement on the absorption spectrum of the ion.

Published: 2016.   Source: Review of Scientific Instruments 87, 053103 (2016)

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