There are different types Fused Silica according the different application. In China, there are mainly three types, i.e. JGS1, JGS2, JGS3.Below are the application and their equivalent to other Fused Silica supplier.

JGS1

UV grade Fused Silica: (JGS1) is synthetic amorphous silicon dioxide of extremely high purity. This non-crystalline, colorless silica glass combines a very low thermal expansion coefficient with good optical qualities, and excellent transmittance in thf orientation and temperature instability inherent in the crystalline form. Fused silica is used for both transmissive at ultraviolet. Transmission and homogeneity exceed those of crystalline quartz without the problems on reflective optics, especially where high laser damage threshold is required. JGS1 is transparent in the ultraviolet and visible regions, and has no absorption bands in the 170-250 nm wavelength intervals. It has an intensive OH absorption band in the interval of wavelength 2600-2800 nm.  

JGS1 is used for optics operating in the deep UV and the visible wavelength range (Laser Lenses, Windows, Prisms, Mirrors, etc.). It is practically free of bubbles and inclusions.

JGS2

Optical Grade Fused Quartz (JGS2) provides good UV and visible transmission. It has almost the same physical and chemical properties with JGS1. However only in thin & small sheet pieces, JGS2 is virtually bubble-free. Elements built from larger pieces will most likely contain bubbles, so application should not be sensitive to these inclusions. But in cases where simple light gathering and strong mechanical properties are the primary goals, JGS2 grade provides excellent performance at a low price.  Ideal Applications for JGS2:  

● Condenser optics not concerned with scatter or distortion
● High temperature and pressure applications
● Optical flats, microscope slides and sight glasses

JGS3

JGS3:equivalent to Suprasil 300 (Heraeus). JGS3 is transparent in the ultraviolet, visible and infrared spectral regions, without considerable absorption bands in the 185-250 nm spectral region.