Theoretical background: Light Sources

Introduction light sources

For applications such as transmission, absorption and reflection, illumination sources are needed. Avantes offers a wide range of different light sources, to suit your specific needs. An overview of the different options can be found on this page.

Different types of light sources

Tungsten Halogen light sources are mostly used to do measurements in the visible and NIR range. AvaLight Halogen sources provide a very stable output combined with long bulb lifetime. The high-stability enables their use in reflection and transmission configurations or as an irradiance calibration light source. Most importantly, the Halogen light’s spectral output is a smooth black body curve which provides for maximized dynamic range.

Avantes Deuterium light sources are known for their stable output and are used for UV absorption or reflection measurements. These can also be used as irradiance calibration sources due to their high-stability. The standard AvaLight-DH-S mixes the Halogen light with the Deuterium light, thus producing a wide spectral range light source. The output spectrum of Deuterium light sources exhibits several peaks, with a prominent peak at 656 nm. The AvaLight-DH-S-BAL incorporates a dichroic beam splitter installed to minimize these peaks, providing a smooth spectrum from 200-2500 nm.

Our pulsed Xenon light source is used in applications where a long lifetime and high output power is needed, such as in fluorescence measurements. This is an affordable UV source, but the spectral output is not as smooth and continuous as the AvaLight Halogen and Deuterium light sources. LED light sources provide high power at a precise wavelength. A typical application for AvaLight-LED sources is fluorescence. They provide long lifetime, short warm-up time and high-stability.

For wavelength calibration Avantes offers a variety of sources including Argon, Mercury- Argon, Neon, Zinc and Cadmium. All Avantes spectrometers are factory wavelength calibrated and do not require recalibration as they have fixed slits and optics. For those customers who wish to do their own calibrations, the AvaLight-CAL light sources can be used for recalibration purposes. For auto-calibration AvaSoft-Full provides a calibration procedure to make this easy.

Table Light sources

Application

Wavelength Range

Type

Principle

Product

Color / VIS / NIR

360-2500 nm

Tungsten Halogen

Continuous

AvaLight-HAL(-S)

DUV

190-400 nm

Deuterium

Continuous

AvaLight-D-S-DUV

UV

215-400 nm

Deuterium

Continuous

AvaLight-D-S

UV/VIS/NIR refl./abs.

215-2500 nm

Deuterium/Halogen

Continuous

AvaLight-DH-S-(BAL)

UV/VIS/NIR absorption

200-2500 nm

Deuterium/Halogen

Continuous

AvaLight-DHc

UV/VIS

200-1000 nm

Xenon

Pulsed

AvaLight-XE

Fluorescence

Multiple possible

LED

Continuous

AvaLight-LED

Wavelength Calibration

253-1704 nm

Mercury-Argon

Neon / Argon

Continuous

AvaLight-CAL

 

Irradiance Calibration

 

200-700 nm

Zinc / Cadmium

Continuous

AvaLight-CAL-CAD/Zinc

360-2500nm

Tungsten Halogen

Continuous

AvaLight-HAL-CAL

200-1100nm

Deuterium/Halogen

Continuous

AvaLight-DH-(BAL)-CAL

Radiance Calibration 360-2500 Tungsten Halogen Continuous AvaSphere-50-LS-HAL-CAL

Spectral distribution light sources

The spectral distribution of the different light source is given in this figure.

allspec2