Working Principle and Application of Optical Fiber Collimator

What Is an Optical Fiber Collimator?

A device that collimates light coming out of an optical fiber, or emits collimated light into the optical fiber. Often, there is a need to transform the output light from an optical fiber into a collimated beam in free space. Theoretically, using a collimating lens can meet this demand. However, the lens requires the fiber port to be at a fixed distance, approximately equal to its focal length. In practice, using an optical fiber collimator is more convenient. There are two different types of optical fiber collimators, one type can directly contact a bare optical fiber. This is a cheap and simple method, but this collimator is usually permanently attached to the fiber. The other type has a mechanical interface between the optical fiber collimator and an optical connector, such as FC or SMA types; these are usually not used with bare fibers. This kind of collimator can be easily installed or removed from a fiber with a connector. The same device can also emit a collimated beam into an optical fiber or be used for fiber-to-fiber coupling, first using the first collimator to collimate the light exiting the first fiber, and then using another collimator to focus the collimated beam into the second fiber. Generally speaking, a fiber connector can be considered a natural interface between fiber optics and free-space optics.

The Principle of MEISU's Optical Fiber Collimators

The basic principle of an optical fiber collimator is to place the fiber end face at the focal point of a collimating lens to collimate the beam, and then finely adjust the position of the fiber end face near the focal point to obtain the required working distance. Therefore, the working distance of the collimator is related to the distance L between the fiber head and the lens. The design method of the optical fiber collimator is to determine the working distance of the collimator according to actual requirements. After determining the distance L between the fiber head and the lens, calculate the spot size based on Gauss beam transmission theory, and then calculate the positioning accuracy of the collimator based on optical theory.

Applications of Optical Fiber Collimators

Fiber optic communication

Optical fiber collimators are indispensable passive optical devices in fiber optic communication systems, used to improve data transmission speed and accuracy. They can be used in circulators, optical switches, collimator arrays, and other optical communication devices to ensure stable transmission of optical signals.

Medical equipment

In laser surgery, optical fiber collimators are used to correct and control the direction and intensity of laser beams, ensuring the safety and effectiveness of the surgery. In light source illumination, optical fiber collimators can input fiber at different angles, making it convenient for medical personnel to illuminate different parts.

Industrial production

In the fields of precision processing and detection, optical fiber collimators are used to control the position and intensity of the laser light source, achieving high-precision processing and detection. For example, they are used for welding and cutting parts in automobile manufacturing; and for detecting weak optical signals on circuit boards in electronics manufacturing.