The materials of the astronomical telescope mirrors we supply usually need to meet the following aspects:
1. Lower thermal expansion coefficient
2. Lower stress birefringence
3. Fine annealing
4. Stable optical performance 5. Bubbles and streaks are effectively controlled.
JGS2 is a very good silica glass, which is widely used in semiconductors, electric light sources, and astronomical instruments. Its main features are as follows:
1. High temperature resistance. The softening point temperature of JGS2 is about 1730℃, and it can be used for a long time at 1100℃, and the maximum use temperature can reach 1450℃ in a short time.
2. Corrosion resistance. The chemical stability of JGS2 at high temperatures is unmatched by any other engineering materials.
3. Good thermal stability. The thermal expansion coefficient of the adaptable glass is very small, and it can withstand severe temperature changes. Heating JGS2 to about 1100°C, it will not burst when placed in water at room temperature.
4. Good light transmission performance. JGS2 has excellent light transmittance in the entire spectrum band from ultraviolet to infrared, and the visible light transmittance is above 93%, especially in the ultraviolet spectral region, the maximum transmittance can reach above 80. 5. JGS2 has good electrical insulation performance. The resistance value of JGS2 is equivalent to 10,000 times that of ordinary glass. It is an excellent electrical insulating material and has good electrical properties even at room temperature.
For a long time, Plexy, which has been known by everyone, may be the only choice, but after continuous experimentation with our customers, JGS2 fused silica material has almost the same properties as one of the choices for astronomical telescope mirrors.
Producing ability | Material | Fused silica ( JGS-2 ) |
Range of dimension | 100mm - 1800mm diameter | |
Range of thickness | 5 mm~300 mm | |
Radius processing | Upon customer's request | |
Center hole | Upon customer's request | |
Measurement / | Dimension | Vernier caliper |
Radius | Coordinate Measuring Machine (CMM) | |
Flatness | Dial indicator | |
Circularity and Concentricity | Dial indicator |