I. Overview
In lighting technology, fiber optic lighting is a unique lighting technology. Because it has flexible transmission of light, it is safe and reliable. Therefore, it is widely used in industrial, scientific research, medical and landscape design, and has formed various products in the domestic and foreign markets. This article focuses on fiber optic lighting technology and products and applications in landscape design with limited knowledge in personal learning and practice to seek peer experts.
Second, the principle of fiber optic lighting
The fiber optic illumination system consists of a light source, a mirror, a color filter, and an optical fiber, as shown in Figure 1.
When the light source passes through the mirror, a bundle of approximately parallel light is formed. The light beam is turned into colored light due to the action of the color filter. When the beam enters the fiber, the colored light is sent to the intended location along the path of the fiber.
The light source is generally strong due to the loss of light on the way. Commonly used light sources are around 150~250W. And in order to obtain an approximately parallel beam, the point of illumination should be as small as possible, similar to a point source.
Mirrors are an important factor in the ability to obtain approximately parallel beams. Therefore, aspherical mirrors are generally used.
A color filter is a part that changes the color of a beam. According to the need, the corresponding color light source is obtained by changing the filters of different colors.
Optical fiber is the main body in a fiber-optic lighting system. The function of the fiber is to transmit or transmit light to a predetermined place. The optical fiber is divided into two types: end light emission and body light emission. The former is that after the beam is transmitted to the end point, it is illuminated by the tail light, and the latter itself is the illuminator, forming a flexible beam.
For fiber optic materials, it must be in the visible range, the loss of light energy should be minimized to ensure the quality of the illumination. However, it is practically impossible to have no loss, so the optical fiber transmission distance is about 30 m.
The optical fiber has three types: single-strand, multi-strand and mesh. For a single-strand fiber, its diameter is Ф6～Ф20mm. At the same time, it can be divided into body light and end light. For multi-strand fiber, it is end-emitting. The diameter of multi-strand fiber is generally Ф0. 5 ~ Ф 3mm, and the number of shares is usually several to hundreds.
The mesh fiber is composed of a thin-diameter bulk light-emitting fiber. It can be composed of a flexible light band.
In theory, light is transmitted in a straight line. However, in practical applications, people want to change the direction of light propagation. After hundreds of years of unremitting efforts by scientists, optical elements such as lenses and mirrors are used to change the direction of propagation infinitely. The emergence of fiber optic illumination is based on the finite number of changes in the direction of light propagation, achieving the flexible propagation of light. Just as the arc is divided into straight lines after numerous divisions, the fiber illumination is reflected in an infinite number of times. Flexible propagation is achieved with the transmission of the fiber. However, the flexible propagation of fiber illumination does not change the classical theory of linear propagation of light.