The collimation angle is the angle at which light rays deviate from a perfectly parallel (collimated) beam . The smaller the collimation angle, the better the beam is collimated and the less the light rays fan out.
1. Characteristics of the collimation angle
✅ Measure the spread of light rays → How much a light beam deviates from perfect parallelism.
✅ Smaller angle = better collimation → A low collimation angle means a tighter, less divergent beam .
✅ Important in optics and laser technology → For precision applications such as lasers, microscopes and telescope lens systems .
✅ Depending on the light source and lens → A laser has an extremely small collimation angle , while an LED has a larger one.
2. How is the collimation angle calculated?
The collimation angle can be estimated using the following formula:
whereby:
- = diameter of the light source or lens opening.
- = focal length of the collimating lens.
📌 Rule of thumb: The longer the focal length , the smaller the collimation angle and the better the light beam is collimated.
3. Applications of the collimation angle
📍 Laser Systems → Essential for cutting and measuring lasers where a narrow beam is required.
📍 Light Beams & Optics → Spotlights, LED Optics & Telescopes.
📍 Medical imaging → Precision optics such as endoscopes and microscopic light guides .
📍 Projection systems → The better the collimation, the sharper the projection over long distances.
📍 Astronomy → Telescope lenses and laser interferometry for space research.
4. Difference between collimation angle and divergence angle
| Feature | Collimation angle | Divergence angle |
|---|---|---|
| Meaning | How well a light beam remains parallel | How wide a beam of light spreads |
| Size | As small as possible for accurate beams | Greater with spreading light sources |
| Example | Laser beam in optical applications | LED light or car headlights |
📌 Small collimation angle = Low divergence = Tight beam of light .
💡 In short:
The collimation angle determines how well a light beam remains parallel . The smaller the angle, the better the beam is collimated, which is crucial in lasers, optics, and precision technology .