NT250 series tunable wavelength UV-NIR range DPSS lasers

The full 335–2600 nm span is achieved by combining three adjacent output regions rather than relying on one conversion branch. With the -SH option fitted, second-harmonic output covers 335–669 nm, the OPO signal covers 670–1064 nm and the idler covers 1065–2600 nm; the option description rounds the UV upper limit to 670 nm. Motorised control and programmable scanning allow the system to move through the configured range without manual wavelength adjustment. In practice, a base NT252 covers 670–2600 nm, while work below 670 nm requires the -SH configuration. Filters, detectors and laser-safety measures must still be selected for each spectral region.

Treat the 1100 µJ OPO value and 200 µJ SH value as reference points at specified wavelengths, not as flat output across the complete tuning range. The OPO figure is measured at the maximum between 700 and 750 nm, while the SH figure is measured at 400 nm, and typical pulse energy changes elsewhere in the range. The available energy at a chosen wavelength therefore needs to be matched against detector sensitivity, sample damage threshold and the required signal-to-noise ratio. For system sizing, include margin for wavelength-dependent conversion efficiency and unit-to-unit variation. Wavelength-specific energy confirmation is advisable before fixing optical attenuation, fibre delivery or exposure settings.

At 1000 Hz, pulses are separated by 1 ms, which can support rapid averaging and scanning when the sample and detector recover within that interval. The OPO pulse duration is 1–4 ns, making the system suitable for nanosecond excitation, photoacoustic generation and pump-probe arrangements that do not require picosecond resolution. Pump pulse energy stability is specified at less than 2.5% standard deviation, but timing jitter is not specified. The experiment should therefore be checked for thermal accumulation, detector dead time and sample relaxation before using the full rate. Where absolute trigger timing is critical, obtain the required jitter and synchronisation details for the selected configuration.

PC-based manual wavelength input uses minimum tuning steps of 1 cm⁻¹ for signal and idler output and 2 cm⁻¹ for SH output. Keypad control is expressed differently, with resolutions of 0.1 nm for signal, 1 nm for idler and 0.05 nm for SH. Because wavenumber and wavelength are inversely related, a fixed cm⁻¹ step does not correspond to the same nm increment across the whole spectrum. PC control is therefore useful when a spectroscopy method is defined in wavenumber spacing, while keypad entry is convenient for direct wavelength selection. The control method should be chosen to match scan spacing, monochromator bandwidth and the linewidth of less than 10 cm⁻¹.

The installation requires a single-phase 100–240 V AC, 50/60 Hz supply and provision for power consumption below 1.5 kW. The laser is air-cooled and specified for 18–27 °C, 20–80% relative humidity without condensation, and room cleanliness of ISO Class 9 or better. Allow space for the 456 × 1040 × 297 mm laser unit, the 520 × 400 × 286 mm power supply and the 2.5 m umbilical. Ventilation clearances should be included around the air-cooled equipment rather than treating the stated dimensions as the complete installation envelope. The system should remain connected to the mains; an interruption longer than one hour can require several hours of warm-up before operation. These requirements should be included in laboratory power, thermal and start-up planning.

Option selection should begin with the required spectral region and beam-delivery method. The -SH option extends tuning into the UV-visible range, -H provides a separate 1064 nm output, and -2H provides a separate 532 nm output; the documented code example NT252-SH-2H combines UV extension with the 532 nm port. The -FC option supplies fibre-coupled output from 350 to 2000 nm, while -ATTN adds attenuation across 335–2600 nm. These ranges mean that fibre delivery does not cover the full idler range to 2600 nm. Before ordering, confirm whether the required output ports, fibre coupling and attenuation can be combined in the same build and whether all outputs are needed simultaneously.

The free-space output has a typical 3 × 6 mm beam diameter measured at the 1/e² level, and the value can vary with pump pulse energy. Signal and SH outputs are horizontally polarised, whereas the idler is vertically polarised, so downstream optics must be chosen and oriented for the active wavelength region. USB, RS232, LAN and WLAN interfaces support integration with control systems, while PC operation is available through supplied LabVIEW drivers. The system is identified as a Class IV laser product, requiring an enclosed or controlled beam path, interlocks, wavelength-appropriate eyewear and management of specular reflections. Integration should therefore treat beam geometry, polarisation, remote control and laser safety as one design task rather than separate installation details.