What is a lensed fiber?

Lensed Fiber

Lensed fiber refers to an optical fiber that has been modified at one or both ends to form a lens. This lensing effect at the fiber's tip is designed to focus or collimate the light coming out of the fiber, enhancing the coupling efficiency between the fiber and other optical components, such as lasers, detectors, and other fibers.

Construction

Lensed fibers are created by shaping the tip of the optical fiber into a specific form. This can be achieved through various methods, including melting, polishing, or applying a separate lensing material to the fiber end. The most common shapes for the lensed tips are spherical, aspherical, conical, or wedge-shaped, each offering different focusing and coupling characteristics.

Applications

Lensed fibers are widely used in a range of applications, including fiber-optic communications, sensors, biomedical imaging, and laser systems. They are particularly valuable in situations where efficient light coupling between fibers and other optical devices is critical.

Advantages

• Improved coupling efficiency, leading to better signal transmission and lower losses.
• Enhanced spatial resolution in imaging applications.
• Ability to focus light into a small spot, useful in laser surgery and precision machining.
• Compact and robust design, suitable for various environments.

Considerations

When designing or selecting a lensed fiber, several factors must be considered, including the lens shape, the refractive index contrast, and the working distance. These parameters must be optimized based on the specific application to achieve the desired performance.