Fiber optic communication is a communication method that uses laser light as the information carrier and optical fiber as the transmission medium. Due to the excellent light transmission performance and extremely high bandwidth of optical fiber, it has become the primary mode of communication, supplemented by microwave and satellite communication. Today, let's learn about optical fiber!
I. What is Optical Fiber?
Optical fiber is a light transmission medium composed of high-purity transparent materials.
Optical fiber composition: Core: SiO2 + GeO2 Cladding: SiO2
*Bare optical fiber structure diagram
II. Fiber Optic Performance
A) Four Determining Factors
1. Geometric Dimensions: Mode field diameter, cladding diameter, cladding non-circularity, core concentricity error, etc., affect splicing and system transmission performance.
2. Environmental Performance: Temperature cycling, high temperature and humidity, temperature delay drift, immersion, nuclear radiation, etc., affect fiber lifespan.
3. Mechanical Performance: Tensile strength, lateral pressure resistance, bending, and torsion affect fiber lifespan.
4. Transmission Performance: Attenuation, dispersion, PMD, nonlinearity, etc., determine system transmission quality.
B) Spectral Curve:
(C) Refractive index distribution diagram of commonly used optical fibers:
III. Fiber Optic Application Development Trends:
1. Core Network Applications: G.655 and G.656 are the development directions.
2. Metropolitan Area Network (MAN) Applications: G.652C fiber/G.652D, G.655, G.656.
3. Access Network Applications: G.652B/D fiber, G.657 fiber.
4. Local Area Network (LAN) Applications: G.651 multimode fiber (50 mm core diameter).
5. Indoor Cabling Applications: G.652B fiber will evolve towards G.657 and plastic fiber.
6. Fiber Optic Research Updates: Photonic crystal fiber.
From Yulia Liu Nov.27th