Fiber optic switch is a non-contact circuit switch composed of a light emitting tube, fiber optic probe, photodetector, amplifier, and output indicator light. The fiber optic probe is composed of a sending fiber and a receiving fiber, with a certain detection space between them. The optical path is used to turn on or off in the detection space, and the circuit switch function is achieved through photoelectric conversion. Used as a circuit switch for various automatic control equipment. To help everyone gain a deeper understanding, this article will summarize relevant knowledge on the characteristics and working principles of fiber optic switches. If you are interested in the content to be covered in this article, then continue reading.

Characteristics of fiber optic switches

Fiber optic switches are devices that can switch fiber optic lines. According to the number of incoming and outgoing lines, it can be divided into 1 × 2, 2x4 and other switches. When switching, the position of the movable optical fiber is changed through electromagnetic induction. The switching time can be as small as milliseconds. Widely used in fiber optic communication systems to provide switching of backup lines. Fiber optic switches have a long lifespan, are safe and reliable, and have strong anti-interference capabilities. They are particularly suitable for applications such as humidity, high temperatures, and strong electromagnetic interference. These switches can be completely immersed in liquids and can also work, and can be installed far away from control systems. But this switch has a higher cost.

Working principle of fiber optic switch

Fiber optic switches are a simple application of quantum technology that converts electrical signals into optical signals, controls photons, opens the switch, generates photons, and then turns them on to work.

Fiber optic is the abbreviation for optical fiber. Optical fibers are transparent filaments with coatings, typically composed of a core material (glass) and a coating (glass). The core material diameter of optical fibers ranges from a few micrometers to tens of micrometers, and the outer diameter of the coating ranges from 0.1 to 0.2 millimeters. The refractive index of the optical fiber coating must be less than that of the core material, and there should be good optical contact between the optical fiber core material and the coating to form a high-quality optical interface. When light enters the incident end face of the optical fiber at an angle of incidence, it refracts and enters the optical fiber at an angle of φ Incident on the smooth interface between the core material and the coating. Just choose the appropriate incident angle θ， It can always make the angular curvature greater than the critical angular curvature required to produce total reflection φ m. The incident light will generate total reflection on the interface; If the optical fiber is a uniform cylinder, the incident light can be completely reflected several times (depending on the length and diameter of the fiber, usually several hundred, several thousand, or even tens of thousands of times) within the optical fiber, and then transmitted from one end of the optical fiber to the other end until it is emitted from the emitting end face.

In general, light propagates in optical fibers, and the absolute values of its energy are equal. Obstacles are set in the middle of the fiber or the total reflection condition of the fiber is destroyed, causing the optical energy output at the fiber outlet to decay. In this way, as long as the optical energy at the fiber outlet is detected, electronic switches can be controlled to control various types of electrical appliances.