Quartz fiber (silicon dioxide) is widely used in optical fiber communication:

The blue column represents the silica fiber! Ingredients: glass!
Plastic optical fiber, the pore size is quite large, the structure reference is as follows:

POF Plastic Optical Fiber, fiber core is made of plastic, the main material is composed of the following parts:
※ Polymers such as polystyrene（PS）
※ PMMA
※ Polycarbonate（PC）
※ Fluorine plastics

Characteristics of plastic optical fiber:
1. Large attenuation, large optical loss, is a thousand times of the quartz fiber
2. Low bandwidth
3. Heat resistance is weak, plastic is not heat resistant
4. The connection distance is short, easy to connect
5. Cheap, cheap, cheap
The communication capacity of one plastic optical fiber can replace 4 copper wire.

The progress of plastic optical fiber to reduce the loss:
※ In 1968, the United States DuPont Co made plastic optical fiber with PMMA.
※ In 1974, Japan MITSUBISHI artificial silk Co use PMMA and polystyrene as core and fluorine plastic as cladding to make the plastic optical fiber. Optical loss is 3500dB/km (Quartz SM fiber 0.2dB/km), It's hard to use in communication.
※ In 1980, MITSUBISHI use high-purity MMA monomer polymerization PMMA, loss decreased to 100-200dB/km.
※ In 1983, NTT company began using deuterium to replace the H atom in PMMA, make minimum optical loss can be reached 20dB/km, can transmit the light wave near-infrared to visible light.
※ In 1986, Japan F Fujitsu Corporation developed SI type heat resistant POF by using PC as core material, heat resistant temperature is up to 135 degrees Celsius, attenuation is up to 450dB/km.
※ In 2000, Japan ASAHI GLASS company reported the attenuation coefficient of fluoride gradient plastic optical fiber (GI-POF) was 70dB/km in 850nm, 33dB/km in 1300nm, bandwidth up to 100mhz/km. High speed transmission test of 50m,2.5Gbit/s was carried out, meet the communication requirements of short distance.

Where they use? We should know about it.
Industry: many use on car, BMW's car communication is using plastic optical fiber.
Air conditioning, refrigerator, kitchen appliances.
Short distance communication: enjoying music, movies, video games and shopping on the plane because of the plastic optical network.
Lighting: gorgeous landscape avenue, optical fiber lamp, plastic optical fiber is used as the light source in the case of coal mine can’t use electricity.
Military: wearable lightweight computer systems for soldier, soft, easy connection, can do without fiber fusion splicer.