Hard-clad silica or polymer-clad fiber (PCF) is an optical fiber

Optical fiber

An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...

 with a core

Core (optical fiber)

The core of a conventional optical fiber is a cylinder of glass or plastic that runs along the fiber's length. The core is surrounded by a medium with a lower index of refraction, typically a cladding of a different glass, or plastic...

 of silica glass (diameter: 200 µm) and an optical cladding made of special plastic (diameter: 230 µm). In contrast to all-silica fiber

All-silica fiber

All-silica fiber, or silica-silica fiber, is an optical fiber whose core and cladding are made of silica glass. The refractive index of the core glass is higher than that of the cladding. These fibers are typically step-index fibers...

, the core and cladding can be separated from each other.
Due to their medium bandwidths and transmission rates of less than 100 MBit/s, HCS fibers are suitable for distances of up to 2 km, e.g. in local networks in buildings and industry. Generally, the following applies: The higher the attenuation, the shorter the distance.

For comparison, plastic optical fiber

Plastic optical fiber

Plastic optical fiber is an optical fiber which is made out of plastic. Traditionally PMMA is the core material, and fluorinated polymers are the cladding material...

s (POF) have low bandwidths and transmission rates (less than 40 MBit/s). They also have a high attenuation and therefore, the maximum distance is around 100 meters. Glass fibers on the other hand have very high bandwidths and transmission rates of up to GBit/s. The attenuation in glass fibres is much lower, glass fibers can cover distances of more than 10 km. Regarding bandwidth and distances, HCS fibers are situated between POF and multimode

Multi-mode optical fiber

Multi-mode optical fiber is a type of optical fiber mostly used for communication over short distances, such as within a building or on a campus...

 or singlemode fiber

Single-mode optical fiber

In fiber-optic communication, a single-mode optical fiber is an optical fiber designed to carry only a single ray of light . Modes are the possible solutions of the Helmholtz equation for waves, which is obtained by combining Maxwell's equations and the boundary conditions...

s.

Application area fiber types

Fiber type	Core/Cladding	Application area	Distance	Data rate
Glass fiber	9/125 µm 10/125 µm	telecommunications	more than 10 km	MBit/s up to Gbit/s
Glass fiber	50/125 µm 62.5/125 µm	local networks in medium areas, buildings and telecommunications	up to 4 km	<155 MBit/s
HCS	200/230 µm	local networks in buildings and telecommunications	up to 2 km	<100 MBit/s
Plastic fiber (POF)	980/1000 µm	local networks in buildings, industry and automotive	up to 100 m	<40 MBit/s

External links

• Hard Clad Silica at Photonics
• Hard Clad Silica at ITWissen