Durable Borosilicate Glass Plate

Borosilicate Glass windows offer superior visual quality and clarity due to their optically polished surfaces. They have a lower melting temperature compared to fused silica, making them easier and less expensive to process. With a higher thermal expansion coefficient than fused silica, they still provide excellent thermal shock resistance. Compared to N-BK7 windows, borosilicate windows have a higher melting temperature and are better equipped to handle thermal shock.

Why Choose Durable Borosilicate Glass Plate ?

Borosilicate Glass windows serve as a practical alternative to fused silica and N-BK7 windows, especially when mechanical strength and thermal shock resistance are required. These windows are commonly used in optics, photonics, and opto-electronics, offering both durability and cost-effectiveness.

Available Shapes of Durable Borosilicate Glass Plate

• Round Optical Windows
• Rectangular and Square Windows
• Step Optical Windows

Sizes of Borosilicate Glass Windows

• Round Windows: Available in diameters up to 400mm.
• Rectangular and Square Windows: Produced in sizes up to 280mm x 280mm.

Minimum Thickness of Borosilicate Glass Windows

• For dimensions less than 20mm: Thickness can be reduced to 0.15mm.
• For dimensions less than 80mm: Thickness can be reduced to 0.25mm.

Custom Optical Windows by Dongqiao Optics

Dongqiao Optics specializes in manufacturing high-quality optical windows, including custom Fused Silica, N-BK7, K9, Borosilicate, Sapphire, Silicon, and other optical materials. These windows are utilized in UV, VIS, and IR spectra, functioning as optical filters and protection covers.

Understanding Optical Windows

Optical windows, often referred to as transparent optical plates or clear optical barriers, are flat panels made from optically clear materials. They are designed to allow light to pass into optical instruments while protecting the light source from environmental conditions.

Key Considerations When Choosing Optical Windows

These windows are engineered to minimize reflection and absorption while maximizing transmission over a specific wavelength range. When selecting an optical window, it is essential to consider the optical surface quality, material transmission properties, and mechanical attributes required for your application.

Streamlined Overview of Substrate Properties for Optical Windows

When selecting custom optics, pay attention to substrate properties and optical surface specifications. These factors determine the transmission, refractive index, and durability of optical windows, directly impacting their performance.

Transmission and Refractive Index

The material of the substrate influences how light passes through it. For example, Potassium Bromide (KBr) substrates efficiently transmit UV, visible, and infrared light. With a density of 2.75 g/cm³ and a refractive index of 1.527, they are ideal for various applications. Zinc Selenide (ZnSe) substrates block UV and some visible light while allowing higher wavelength visible and infrared light to pass, with a refractive index of 2.631. This makes ZnSe highly effective in specific optical systems.

Fused Silica is another popular substrate, featuring a density of 2.202 g/cm³ and a refractive index ranging from 1.55 to 1.40. The refractive index is crucial for achieving precise optical results, as it measures how much light slows down when traveling through the substrate.

Sapphire Windows have a refractive index of 1.76-1.77, typically measured at 587.6 nm (the Helium d-line wavelength). Higher refractive indices, like those found in flint glass, are ideal for dense optical applications, while lower indices, like those in crown glass, are better for lighter applications.

Abbe Number and Dispersion

The Abbe Number indicates how the refractive index changes with wavelength. Lower Abbe numbers correspond to higher dispersion, which is critical for color correction and reducing chromatic aberration. Sapphire has an Abbe number of 72.24, while BK7 glass has an Abbe number of 64.17, both offering excellent optical clarity.

MgF2 (Magnesium Fluoride) Windows

MgF2 windows are renowned for their hardness and durability. With a refractive index of 1.378 and an Abbe number of 106.22, they provide exceptional broadband transmission from 120 nm to 8 μm. These windows are ideal for UV radiation sources and high-performance optical systems, thanks to their high laser damage threshold.

Density Considerations

For weight-sensitive applications, substrate density is a key factor. While higher density often correlates with a higher refractive index, this relationship is not always linear. Careful consideration of both density and refractive index is essential when selecting the right material for your optical windows.

By carefully optimizing these substrate properties, you can ensure that your optical windows deliver high performance and longevity in your specific application.