The collimated light is a kind of light whose rays are parallel and spread minimally as it propagates. The term collimated is “collinear” and infers that it doesn’t scatter with distance or will scatter negligibly.
A perfectly collimated beam without divergence cannot be created due to diffraction. Light can be approximately collimated by several processes, for instance, using a kilometer. Perfectly collimated light is sometimes said to be focused at infinity versus the distance. From the point the source expands, the circular wavefronts become compliment and nearer to impeccably collimated plane waves.
The Term collimation also refers to all the optical elements in an instrument on the designed optical axis. It also refers to the process of adjusting an optical device, so all its elements are on that designed axis with regards to a telescope. This term also refers to the optical axis of each visual component which has to be centered in parallel so that the collimated light emerges from the eyepiece.
Now, let’s come to fiber optics and collimation from a fiber.
When do people need a collimated filament light source?
In many fiber optic applications, customers need collimated light to emerge from their fiber optics cable. To collimate light, one must place the lens at an equal distance to its focal length away from the source. For this to work, the Nano-Optics offers optic collimator and focuser assemblies.
These products are attached to standard connectors on the end of fiber optic cables and position the lens at its focal length away to collimate the light. They’re designed for specific wavelengths since the focal length of the lens shifts slightly with wavelength.
The fibers and fiber optic collimators are also specified by their numerical aperture, which defines the light cone angle accepted by optic or fiber. Suppose the numerical aperture of a source is greater than the numerical aperture of the optic. In that case, the optic is considered overfilled, and not all of the light will be collected by the optic. But, if the numerical aperture of the source is smaller than the numerical aperture of the optic, then the optic is considered underfilled, and all the light will be collected. Still, it won’t span over the entire aperture of the optic.
Moving to guide for setting up fiber optic illuminator and collimated filament light source;
If you move a stage further from the light guide, you will notice that light diverges. By attaching one of the fiber light focusing lenses, the light can be collimated. A standard optical component used for coupling light from a laser into fiber optic is known as a ball lens.
The ball focal points are best for the sign coupling between strands, producers, and locators. They can shine or collimate light contingent on the math of the information source. The decision of the ball focal point relies upon the mathematical opening of fiber and source.
Both underfilling and overloading apply to ball focal points too.
How to know if a light is collimated?
Well, if you have a focal point with an obscure central length, you can utilize collimated light to decide its mid-size. We can expect that light is collimated or coming from boundlessness if the light source is more prominent than a distance equivalent to 10x the mid-length of the focal point away.