Sapphire custom plates with a single-side polished surface are high-precision optical and structural components manufactured from premium single-crystal aluminum oxide (Al₂O₃). Owing to their exceptional hardness, excellent optical transmission, high thermal resistance, and chemical stability, sapphire plates have become indispensable in advanced optical systems, semiconductor processing, high-end industrial equipment, and scientific instrumentation. The single-side polished design (commonly referred to as single-polish or single-side mirror finish) provides a cost-effective yet highly functional solution for applications that require only one optical-grade surface.

Unlike double-side polished components, single-side polished sapphire plates retain one highly refined optical surface while the opposite side remains lapped or semi-finished. This configuration is widely used in scenarios such as protective windows, light-entry surfaces, sensor covers, inspection fixtures, and structural support plates, where only one surface undergoes optical interaction while the other serves as a mounting or bonding interface.

Material Characteristics

Sapphire is one of the hardest optical materials available, ranking 9 on the Mohs scale—second only to diamond. This exceptional hardness ensures long-term scratch resistance and durability in harsh environments. In addition, sapphire exhibits excellent transmission from ultraviolet (UV) to infrared (IR) wavelengths, making it suitable for broadband optical applications.

Its high thermal conductivity and melting point (~2050°C) allow sapphire to perform steadily in high-temperature conditions. It also sports superior chemical inertness, resisting acids, alkalis, and most solvents. These combined properties result in a durable, stable, and multifunctional material suitable for precision engineering fields.

Key Product Features

1. Single-Side Optical Polishing

The polished surface can achieve roughness levels as low as Ra < 1 nm, providing high clarity, minimal scattering, and excellent surface quality. This ensures compatibility with optical systems requiring strict surface precision, such as laser instruments and imaging equipment.

2. High Mechanical Strength

Sapphire custom plates can endure extreme mechanical impacts and abrasive wear. They maintain high bending strength, compressive strength, and structural stability even in continuous-duty industrial equipment.

3. Excellent Thermal and Chemical Stability

Sapphire maintains stable performance under high thermal loads, rapid temperature cycling, and exposure to corrosive chemicals. This makes it suitable for semiconductor equipment, high-temperature inspection windows, and harsh-environment optical components.

4. Full Customization Capability

Dimensions, shapes, cut angles (C-plane, A-plane, R-plane), thickness tolerances, flatness grades, chamfer dimensions, and surface roughness are all customizable. Additional machining—laser cutting, ultrasonic drilling, grooves, steps, slots, and edge shaping—is available based on drawings.

Typical Specifications (Fully Customizable)

Applications

Optical and Laser Systems

Single-polished sapphire plates are widely used as protective windows for lasers, optical sensors, and imaging systems. The polished surface ensures excellent optical performance, while the unpolished side serves as a bonding or mounting surface.

Precision Instrumentation

These plates act as viewports, detection windows, and inspection interface components in industrial metrology systems. Sapphire’s scratch resistance and stability make it ideal for long-term precision measurement environments.

Semiconductor Equipment

Sapphire’s thermal resistance and chemical inertness enable its use in wafer inspection tools, test fixtures, probe stations, and chamber protection windows.

Harsh-Environment Protection

Sapphire plates withstand sand, dust, chemicals, high temperature, and mechanical shock better than most glass materials, making them ideal for aerospace, underwater cameras, and high-pressure systems.

Consumer Electronics

Sapphire camera windows, cover plates, and biometric sensor covers benefit from the scratch-proof nature of single-crystal sapphire.

Advantages of Single-Side Polishing

1. Cost-effective solution compared with double-polished plates.

2. Ideal for applications where only one optical interface is required.

3. Better bonding compatibility for the matte or lapped side.

4. Flexibility in assembly, especially for mechanical clamping or adhesive mounting.

5. Reduced light reflection on the non-polished side in some optical designs.

FAQ

Q1: Can sapphire plates be made extremely thin?
Yes. We can produce sapphire plates down to 0.15–0.2 mm depending on size. Thinner pieces can be evaluated based on drawings and tolerance requirements.

Q2: Do you support complex shapes or micro-machining?
Absolutely. We support laser cutting, ultrasonic drilling, rectangular or contour shaping, slots, blind holes, steps, and through-holes.

Q3: What wavelength range does sapphire transmit?
Sapphire offers excellent transmission from 150 nm (UV) to over 5 μm (IR), making it suitable for UV, visible, and near-IR optical systems.