Choosing A Light Source For Your Spectrometer
Depending on your spectrometer application, you will probably need at least one illumination or excitation source. This excitation can come in various forms. For example, electroluminescence measurements will require of some sort of testing board connected to an external voltage source. However, most characterisation of optical materials require some sort of incident light.
The light source you will need to use depends on the measurements you are doing. For photoluminescence measurements, you will need a monochromatic light source with a higher energy than the transition you wish to measure. However, for absorbance measurements you will need a broadband illumination source.
There are many things to consider when you are choosing light sources for your optical spectroscopy lab. The best light source for you will depend on:
- The type of measurements you are doing
- The specifications of your spectrometer
- Your budget
- The safety restrictions of your lab.
- The time needed to set-up and maintain your light source
One important thing to note is that you will need different light sources for different optical measurements. Therefore, it is quite likely that you will need more than one light source in order to fully characterise your organic electronic materials.
Optical Spectroscopy Kit
- Excellent Value
- Precision Optics
- Free Software + Updates
Worldwide Delivery £2400
Comparing Different Spectroscopy Light Sources
In the table below, we have done a brief comparison of different light sources. Here, we have outlined their ideal applications, costs and other important information.
| White Light LED | Tungsten Halogen + Deuterium Light Sources | UV LED Light Source | Lasers | |
| Type | Broadband | Monochromatic | ||
| What measurement is this for? |
|
Photoluminescence measurements |
|
|
| Advantages | Long bulb lifetimes | Wide spectral range | Long bulb lifetimes |
|
| Cost | Low price and low running costs | High ($4000-$5000) | Low | High ($1000 – $6500) |
| Emission Spectra | Broad spectrum (360 nm – 900 nm for Ossila Broadband White Light) | Very broad spectrum (190 nm – 2200 nm) | Well-defined narrowband emission (e.g. 370 nm for Ossila UV LED) | Well-defined emissions (can be tunable depending on the laser) |
| Warm-Up Time | Minimal | 30 minutes – 1 hour | Minimal | 5–60 minutes (will vary depending on laser material and mode) |
| Temperature Control Needed? | No | Yes – to stop overheating | No | Most likely – but depends on the laser |
| Set Up and Calibration Time | Low | Low | Low | High |
| Safety Considerations | Low | Low | Low–Medium | High |
In order to take the broadest range of general spectroscopy measurements, you will need at least one broadband and one monochromatic light source.
Ossila Light Sources
Ossila sell two low-cost light sources which are compatible with the Ossila Optical Spectrometer, but also with other spectroscopy equipment via the use of standard optical fibers. This will enable you to take a range of optical spectroscopy measurements quickly and easily.
UV Light Source
Our USB-C powered UV Light Source emits light at 370 nm. It will not be as powerful as laser excitation but is considerably safer.
Suitable for:
- Optical excitation in visible fluorescence spectroscopy measurements.
Broadband White Light Source
Our LED Broadband White Light Source outputs light over the entire visible spectrum (360 nm - 900 nm). This white light source is considerably smaller than tungsten/deuterium sources.
Suitable for:
In combination, these two light sources will provide you with everything you need to take basic spectroscopy measurements. These are compatible with standard spectroscopy fittings (SMA 905 fiber connections, M6 optical breadboard holes) so that they can be easily integrated with any spectroscopy system.
Optical Spectroscopy Kit
- Excellent Value
- Precision Optics
- Free Software + Updates
Worldwide Delivery £2400