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Monochromator
Monochromator
Introduction
The term monochrome and its variants come to us from the Greek words mono “single” and chroma “colour”.
Light Dispersion Mechanisms
Mechanism | Dispersion Process | Pros | Cons |
---|---|---|---|
Prism | Refraction |
- Simple
- Inexpensive
|
- Prism material absorbs light
- Non-linear dispersion
|
Reflection diffraction grating | Diffraction | Can be optimised |
- Linear dispersion
- Complex process
- Delicate optics
- Expensive
- Delicate optics
|
Transmission diffraction grating | Diffraction | Relatively simple |
- Linear dispersion
- Expensive
- Complex process
- Delicate optics
- Grating material absorbs light
|
Band Pass Filter | Band pass filters |
- Simple
- Relatively inexpensive (in visible-NIR only)
|
- Low spectral resolution
- Low throughput
|
Of the above techniques, only the reflection diffraction grating can be used over wide spectral range in a practical application, providing potentially very high spectral resolution.
Wave Interference
▲Figure 1-5:-Wave interference