Pro Lite Technology

LED Light Sources for Spectroscopy

Phos-4 LED Light Sources

The Phos-4® is a precision, UV-VIS-NIR, fibre-coupled light source purpose designed for precision spectroscopic analysis. Phos-4 LED light sources are available either with either single wavelength or multi-wavelength modules. Interchangeable, temperature controlled LED modules provide stable outputs between 285 and 730nm. Applications for Phos-4 LED sources include the measurement of reflectance, transmittance and absorbance, as well as in the measurement of fluorescence and for industrial illumination.


  • Temperature & voltage clamped
  • Wavelength flexibility: 285-730nm
  • Up to 4 LED drives for single and multi-LED modules
  • 4 independent linear mode current drives
  • USB, UART, TTL & analogue interfaces
  • Supports in-line optical filters

Powerful Scientific Illumination

All the Phos-4 LED modules are based on high power, surface mount LEDs. With some of the LEDs developing up to 150 mW total flux and with a radiant intensity value of >300 mW/sr, coupling into a 600µm 0.39 NA fibre can exceed 20mW. Precise XYZ adjustment of the output focussing lens ensures optimal coupling into either an SMA-905 fibre or into 16mm (5/8") optical fibre bundles. Diffusers and filters can be added to the output of the light source.

Output Stability for Improved Data Quality

The output of non-scientific LED illuminators varies both  with drive level and with temperature. The Phos-4 design solves both these problems to yield an incredibly stable LED light source. Each of the 4 independent LED drives is based on a ±8ppm voltage reference. Combine that with thermal clamping to 35 ±0.02°C, and the drift in the output power can be as low as -0.02% / hour in continuous mode. The thermal clamp and precision drive also means you can be sure that the spectral output will be as stable as possible.

Wavelength Flexibility

The beauty of the Phos-4 is that you have the utmost in illumination flexibility:

  • Wavelength Selection
  • User Interchangeable LED Modules
  • Wavelength options ranging from 285 nm to 730 nm
  • Multi-LED die devices allowing adjustable combinations of wavelengths

The Phos-4 is the only integrated fibre coupled LED light source that allows you to control multi-die LEDs. What does that mean? Well the options are endless but here are a few:

  • Need a white light ranging from 400 to 700nm? Try the P4-VCAW-U00.
  • Comparing fluorescence intensity at 400 and 450nm? Try the P4-VGRB-U00.

Power is Nothing without Control

Phos-4 incorporates four independent LED drives, delivering upto 800mA per channel and 1,200mA in total over 4 channels. Control options include:

  • USB (for PC, LabView, MatLab)
  • UART (µControllers)
  • TTL logic controls
  • DC (analogue) voltage input


Related Products

> Reflectance
> Transmittance
> Absorbance
> Fluorescence

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