Synthetic Sapphire, the single crystal form of Al2O3, is one of the hardest materials ( 9 Mohs hardness). Because of its structural strength, the sapphire crystal can be made much thinner than other common optical crystals, with better transmittance performance.

2. High thermal stability and excellent thermal conductivity make the sapphire crystal suitable for the applications in high power. The loss in a sapphire crystal is less than in another common optical crystal.

3. sapphire crystals can withstand considerably higher temperatures than most optical crystals with zero degradation.

4. sapphire crystals will not get dark and lose their brilliancy when exposed to UV light.

5. sapphire crystals are extremely stable and resistant to attack by strong acid due to sapphire’s high dielectric constant.