Single-mode fiber optic patch cord plays a key connecting role in the field of optical communications. Its bending radius has an important impact on signal attenuation, and there is a specific influencing mechanism behind it.
First, when the single-mode fiber optic patch cord is bent, the propagation path of the light in the fiber core will change. The light that originally propagates in a straight line will deviate from the ideal path at the bend due to refraction and reflection effects. A smaller bending radius will change the incident angle of the light at the interface between the core and the cladding. Some light may be incident on the cladding at a larger angle, causing more light energy to leak into the cladding, thereby causing signal attenuation.
Secondly, bending will cause uneven stress distribution inside the optical fiber. When the bending radius is too small, the optical fiber close to the inner side of the bend is squeezed, while the outer side is stretched. This stress change will cause a slight change in the refractive index distribution of the optical fiber, which no longer meets the ideal single-mode transmission conditions. The optical signal will undergo mode coupling and other phenomena, causing the transmitted light energy to disperse, thereby increasing signal attenuation.
Furthermore, from a microscopic structure point of view, single-mode optical fiber is made of glass material, and excessive bending may cause damage to the microstructure of the core and cladding. For example, tiny cracks or defects may occur, which will cause light to scatter during propagation. The scattered light cannot move along the predetermined transmission direction, which will eventually lead to a decrease in signal strength, that is, an increase in signal attenuation.
In addition, the coating material of the single mode fiber optic patch cord also plays a role in the bending process. If the bending radius is too small, the coating may not be able to effectively buffer the impact of external stress on the optical fiber, aggravating the structural changes inside the optical fiber, and indirectly causing the signal attenuation to increase.
From the perspective of optical principles, a small bending radius will destroy the total reflection condition of light in a local area. Light relies on total reflection in the optical fiber to achieve low-loss transmission, and the change in geometric shape caused by bending makes some light unable to meet the critical angle requirements of total reflection. These light rays will escape from the fiber core, causing signal energy loss and attenuation.
In practical applications, different bending radii have different degrees of influence on signal attenuation. Generally speaking, the closer the bending radius is to the minimum allowable bending radius of the optical fiber, the greater the increase in signal attenuation.
The bending radius of the single mode fiber optic patch cord has a significant impact on signal attenuation through multiple mechanisms such as changing the light propagation path, causing uneven stress distribution, destroying the microstructure, affecting the coating effect, and changing the total reflection conditions. Therefore, when installing and using the single mode fiber optic patch cord, its bending radius requirements must be strictly followed to ensure the quality and stability of signal transmission.
