meisuoptics
https://www.meisuoptics.com/fiber-lens-lensed-fiber.html
Principle and application of optical fiber lens
Optical fiber len, also known as optical fiber lens or lens fiber, is made by processing the tip of the fiber into the shape of a certain lens. It is used to change the optical path or transform the optical mode in optical system.
Different fields require for different fiber lenses. In terms of the shape of lenses, they can be divided into inclined plane, wedge (double inclined plane, or four inclined plane), sphere, conical, etc., as shown in picture below. Moreover, lensed optical fiber can also be divided into single fiber lens and fiber lens combination based on the form of fiber lens. This paper mainly introduces the principle and application of different types of fiber lenses.