Optical Grade Quartz Single Crystal Wafers

Application of Optical Grade Quartz Single Crystal Wafers

• Optical low-pass filters for digital cameras
• Polarizers and polarifiers in optical instruments
• Optical isolator and optical fiber coupler in optical fiber communication
• Semiconductor and microelectronics

Advantages of Optical Grade Quartz Single Crystal Wafers

• Wide light transmission range
• Good optical uniformity
• Corrosion resistance
• Superior light transmission
• Super high insulation
• High-temperature resistance

Ability of Optical Grade Quartz Single Crystal Wafers

• Orientations: X/Y/Z-cut etc.
• Diameter: 1”, 2”, 3”, 4”
• Thickness: 0.2 mm, 0.5 mm, 1.0 mm etc.
• Available items: crystal wafers, blanks and customized optics

Quality Evaluation of Synthetic Quartz Crystal

a) The amount of crystal defect and impurity in synthetic quartz crystal depends on growth rate, mineralizer and raw material. The growth rate affects greatly to the important properties such as infra-red absorption coefficient α, which correlates to Q value, and frequency –temperature characteristics. The larger growth rate causes increase in α, decrease in Q value, and dispersion in frequency-temperature characteristics.

b) The quality index of synthetic quartz crystal was originally a Q value, and a 5 MHz quartz crystal unit operated in 5th overtone mode was used to obtain the Q value. But it required laborious work to fabricate the 5 MHz crystal unit, so the index had been changed to the coefficient α instead of the Q value.

Standard Specification for Synthetic Quartz Crystal

a) Twinning: There shall be no electrical or optical twinning in the usable region.

b) Strain: There shall be no strain contained both inside and surface of seed crystal as well as in a grown quartz crystal.

c) Cracks and fractures: There shall be no cracks, chippings or fractures in the usable region.

d) Inclusion density: The specification is in accordance with the IEC 60758.