What are sapphire windows?

Sapphire windows are optical or protective windows manufactured from single-crystal aluminum oxide (Al2O3). They offer exceptional hardness, scratch resistance, wide transmission from UV to mid-IR, and high thermal and chemical stability, which makes them ideal for high-pressure, high-temperature and harsh-environment applications.

What is natural sapphire?

Natural sapphire is a crystalline form of aluminum oxide that occurs in the Earth’s crust. It is extremely hard, thermally stable and resistant to abrasion and chemicals. These properties make natural sapphire useful for durable optical windows, watch crystals, lenses and other components that require long life in demanding environments.

What is synthetic sapphire?

Synthetic sapphire is grown in a crystal furnace using methods such as Czochralski, Verneuil or Kyropoulos growth. The process reproduces the structure and properties of natural sapphire but allows tight control over purity, size, orientation and thickness. Synthetic sapphire windows and wafers are widely used in optics, LED manufacturing, consumer electronics and high-strength transparent armor.

What are sapphire optical windows used for?

Sapphire optical windows are used to protect sensors, lasers, cameras and analytical instruments while maintaining high transmission from deep UV to the infrared. Typical applications include medical and industrial equipment, high-temperature view ports, spectroscopy systems, barcode scanners, pressure vessels, and optical assemblies that require high strength and scratch resistance.

Which sapphire wafer orientations are available?

Common sapphire wafer orientations include C-plane (0001), A-plane (11-20), M-plane (10-10) and R-plane (10-12). Different orientations are chosen for epitaxy, optical birefringence, mechanical properties and specific device structures. UniversityWafer, Inc. stocks A-, C-, M- and R-plane sapphire windows and wafers and can supply custom sizes and thicknesses for research and development.

Sapphire Windows (Al2O3) for Research & Development

Q: What are sapphire waveplates?

Sapphire waveplates exploit sapphire’s birefringence to control polarization. They can be manufactured as quarter-wave or half-wave plates and used from the visible into the infrared. Because sapphire is very hard and chemically robust, sapphire waveplates are well suited for high-power lasers and demanding laboratory or industrial environments.

Sapphire Substrates for Graphene Deposition

UniversityWafer supplies sapphire wafers, diced sapphire pieces, and graphene samples for thin-film deposition, Raman characterization, atomic force microscopy, semiconductor research, photonics, sensors, and advanced materials development.

Sapphire is frequently selected as a graphene growth or transfer substrate because it offers excellent surface stability, high-temperature resistance, electrical insulation, optical transparency, and compatibility with thin-film processing. Researchers may also request monolayer graphene transferred onto thermal oxide silicon substrates for easier optical identification and electrical device fabrication.

A research and teaching assistant requested the following materials:

Research request:

We would like to order sapphire wafers and monolayer graphene on 285 nm SiO₂/Si. Could you provide information about the delivery time, material quality, and price?

We are also interested in monolayer graphene on 300 nm SiO₂/Si with dimensions of 70 × 70 mm. What percentage of the sample is covered by monolayer graphene?

Can the 70 × 70 mm sample be diced into 10 × 10 mm pieces, providing 49 samples in total?

Can you provide Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) data? Is a large-area Raman map also available?

Graphene Sample Availability and Characterization

The following information was provided for monolayer graphene on 300 nm SiO₂/Si with a 70 × 70 mm substrate size:

Estimated lead time: Approximately three weeks, depending on current inventory and requested processing.
Graphene coverage: Full substrate coverage was available for the quoted material.
Available sample sizes: 70 × 70 mm sheets or standard 10 × 10 mm diced graphene samples.
Cost and delivery: Standard 10 × 10 mm samples may have a shorter lead time and lower cost than custom large-area pieces.
Raman characterization: Raman measurements can be performed at multiple locations across the sample.
Additional analysis: Ask about Raman mapping, AFM surface images, XPS analysis, defect density, layer count, and graphene uniformity.

Reference #164511 for sample quality, available sizes, characterization options, specifications, quantity, and pricing.

Request a Sapphire or Graphene Quote

Send us your required substrate material, dimensions, sapphire orientation, graphene layer count, oxide thickness, sample coverage, dicing requirements, characterization data, and quantity. UniversityWafer can help identify suitable sapphire wafers, thermal oxide silicon wafers, and graphene samples for your research.

Get Your Sapphire or Graphene Quote FAST! Or, Buy Sapphire Wafers Online and start researching today.

Buy Sapphire Wafers and Windows Online

UniversityWafer supplies single-crystal sapphire wafers and optical windows for LEDs, GaN epitaxy, power semiconductors, RF electronics, graphene research, photonics, lasers, sensors, watch crystals, and harsh-environment optical systems.

Researchers can purchase small quantities for laboratory testing or larger volumes for production. Standard and custom sapphire substrates are available in diameters and dimensions ranging from small diced pieces to wafers up to 200 mm.

Available specifications may include C-plane orientation, single-side polishing, double-side polishing, thin sapphire wafers, epi-ready surfaces, custom thicknesses, and diced rectangular or square pieces.

Item Number	Diameter or Size	Orientation	Thickness	Polish
3156	Rectangle	C-plane <0001>	500 µm	SSP
3467	10 × 10 mm	C-plane <0001>	430 µm	DSP
3409	6.0 mm	C-plane <0001>	100 µm	DSP
1251	50.8 mm	C-plane <0001>	430 µm	DSP
1306	50.8 mm	C-plane <0001>	430 µm	SSP
2768	50.8 mm	C-plane <0001>	330 µm	DSP
3407	50.8 mm	C-plane <0001>	100 µm	DSP
1732	100 mm	C-plane <0001>	650 µm	SSP
2562	100 mm	C-plane <0001>	650 µm	DSP

Available Sapphire Wafer Sizes

50.8 mm Sapphire Wafers — 430 µm, DSP
76.2 mm Sapphire Wafers — 350 µm, SSP
100 mm Sapphire Wafers — standard and custom thicknesses, SSP or DSP
150 mm Sapphire Wafers
200 mm Sapphire Wafers — available with custom thickness and polishing specifications

Other sapphire diameters, rectangular windows, diced substrates, thin wafers, custom crystal orientations, surface finishes, and thickness tolerances may also be available upon request.

How to Specify a Sapphire Wafer

To receive an accurate sapphire wafer recommendation, include the following:

Diameter or dimensions
Crystal orientation: C-plane, A-plane, M-plane, or R-plane
Thickness and tolerance
Surface finish: SSP, DSP, epi-polished, lapped, or unpolished
Surface roughness, bow, warp, and TTV requirements
Dicing, edge shaping, or custom fabrication requirements
Coating or deposited film requirements
Quantity and intended application

Optically polished sapphire windows for lasers, sensors, and research applications

Sapphire Windows, Wafers, and Optical Substrates

Sapphire, also known as single-crystal aluminum oxide (Al₂O₃), combines excellent optical transmission, high mechanical strength, chemical resistance, electrical insulation, and exceptional scratch resistance. These properties make sapphire wafers and sapphire windows suitable for demanding research, semiconductor, photonic, medical, industrial, and high-temperature applications.

UniversityWafer supplies A-plane, C-plane, M-plane, and R-plane sapphire substrates in standard and custom diameters, thicknesses, orientations, and surface finishes. Available configurations include single-side polished (SSP), double-side polished (DSP), epi-ready, optically polished, lapped, and diced sapphire pieces.

Polished sapphire wafer for optical, semiconductor, and research applications

Key Properties of Sapphire

Sapphire is frequently selected when conventional glass, quartz, or other optical materials cannot provide the required combination of strength, thermal stability, and optical performance.

High hardness and abrasion resistance — Sapphire has a Mohs hardness of 9 and resists scratching in harsh environments.
Wide optical transmission — Optical sapphire can transmit wavelengths from the ultraviolet through the visible and into the mid-infrared, depending on material quality, thickness, polish, and coatings.
High-temperature stability — Sapphire maintains useful mechanical and optical properties at temperatures where many glasses soften or deform.
Chemical resistance — Single-crystal Al₂O₃ withstands many corrosive chemicals and process environments.
Electrical insulation — Sapphire is used as an insulating substrate in RF electronics, semiconductor devices, sensors, and silicon-on-sapphire technologies.
High mechanical strength — Thin sapphire windows can provide excellent resistance to pressure, impact, and mechanical wear.
Birefringence — Sapphire is optically anisotropic, so crystal orientation must be considered for polarization-sensitive optical systems.

Common Sapphire Applications

Sapphire wafers, windows, and diced substrates are used across optics, microelectronics, semiconductor fabrication, and materials research.

GaN and III-nitride epitaxy for LEDs, laser diodes, photodetectors, and power electronics
Graphene growth and deposition
Optical windows for cameras, sensors, lasers, and spectroscopy systems
High-temperature and high-pressure viewports
Infrared and ultraviolet optical components
RF, microwave, and high-frequency electronic devices
Silicon-on-sapphire integrated circuits and radiation-resistant electronics
MEMS, biosensors, microfluidic devices, and analytical instruments
Protective covers for barcode scanners, fingerprint sensors, and displays
Watch crystals, wear-resistant surfaces, and transparent protective components
Medical, aerospace, defense, and industrial optical assemblies

Sapphire Crystal Orientations

Sapphire is an anisotropic single crystal. Its optical, epitaxial, mechanical, and surface properties vary with crystallographic orientation. The correct orientation should therefore be selected according to the deposition process, device structure, optical path, or mechanical requirement.

Orientation	Miller Index	Common Uses
C-Plane	(0001)	GaN and AlN epitaxy, LEDs, semiconductor research, optical devices, and general sapphire wafer applications
A-Plane	(11-20)	Nonpolar epitaxy, optical components, dielectric substrates, and specialized thin-film research
M-Plane	(10-10)	Nonpolar nitride growth, optoelectronics, optical research, and orientation-dependent material studies
R-Plane	(10-12)	Silicon-on-sapphire, RF electronics, piezoelectric films, optical components, and specialized epitaxial research

C-Plane Sapphire Wafers

C-plane sapphire wafers are among the most commonly used sapphire substrates. The (0001) surface is widely selected for GaN, AlGaN, and AlN epitaxy, LED fabrication, optoelectronics, dielectric research, and thin-film deposition.

Representative 50.8 mm C-plane specification:

Diameter: 50.8 ± 0.1 mm
Orientation: C-plane (0001)
M-axis off-cut: 0.2 ± 0.1°
A-axis off-cut: 0 ± 0.1°
Primary flat orientation: A-plane (11-20) ± 0.3°
Primary flat length: 16.0 ± 1 mm
Thickness: 400 ± 15 µm
Total thickness variation: ≤10 µm
Bow: ≤10 µm
Surface roughness: Ra ≤0.3 nm
Front surface: Epi-polished
Back surface: Fine-ground or polished, depending on the required configuration

Additional C-plane sapphire pieces may include:

5 × 5 × 0.5 mm, C-plane (0001), SSP
5 × 5 × 0.5 mm, C-plane (0001), DSP
10 × 5 × 0.5 mm, C-plane (0001), DSP
10 × 10 × 0.1 mm, C-plane (0001), DSP
10 × 10 × 0.1 mm, C-plane (0001), SSP

A-Plane Sapphire Wafers

A-plane sapphire has a (11-20) surface orientation. It is used for nonpolar epitaxial growth, optical components, thin-film research, and applications where the crystal orientation must differ from conventional C-plane sapphire.

Al₂O₃ sapphire, 5 × 5 × 0.5 mm, A-plane, DSP
Al₂O₃ sapphire, 5 × 5 × 0.5 mm, A-plane, SSP

M-Plane Sapphire Wafers

M-plane sapphire has a (10-10) surface orientation. It is commonly investigated for nonpolar III-nitride epitaxy, orientation-dependent optical properties, photonics, and advanced materials research.

Al₂O₃ sapphire, 5 × 5 × 0.5 mm, M-plane, DSP
Al₂O₃ sapphire, 5 × 5 × 0.5 mm, M-plane, SSP

R-Plane Sapphire Wafers and Windows

R-plane sapphire has a (10-12) surface orientation. It is used for silicon-on-sapphire electronics, RF and microwave devices, piezoelectric thin films, optical components, and specialized epitaxial structures.

Part Number	Size	Orientation	Available Quantity	Surface Finish
A.23.0309	107.95 × 1.2195 mm	R-plane	4	Unpolished
A.24.0011	100 × 0.5 mm	R-plane	5	Single-side polished
A.24.0024	50.8 × 0.43 mm	R-plane	22	Single-side polished
A.25.0062	100 × 0.5 mm	R-plane	17	Double-side polished
A.32.0096	82.55 × 68.072 mm	R-plane	464	Unpolished
A.33.0217	82.55 × 68.072 × 2.413 mm	R-plane	4	Unpolished
A.33.0218	82.55 × 68.072 × 2.794 mm	R-plane	18	Unpolished
A.35.0055	25.4 × 25.4 × 0.254 mm	R-plane	26	Double-side polished

Inventory and available quantities may change. Contact UniversityWafer for current availability, custom polishing, dicing, thickness tolerances, and delivery information.

What Are Sapphire Optical Windows?

Sapphire optical windows are transparent protective components manufactured from single-crystal Al₂O₃. They protect cameras, detectors, sensors, lasers, pressure vessels, and analytical instruments while allowing ultraviolet, visible, or infrared radiation to pass through.

Compared with conventional optical glass, sapphire offers greater hardness, abrasion resistance, thermal stability, and mechanical strength. These characteristics allow sapphire windows to be made relatively thin while still providing protection in high-pressure, high-temperature, chemically aggressive, or high-wear environments.

Polished optical sapphire windows for lasers, sensors, and high-pressure applications

Synthetic Sapphire for Research and Industry

Most technical sapphire wafers and optical windows are manufactured from synthetically grown single crystals rather than mined gemstone material. Controlled crystal growth allows manufacturers to specify purity, crystallographic orientation, diameter, thickness, surface finish, and optical quality.

Synthetic sapphire may be produced using crystal-growth methods such as Kyropoulos, Czochralski, Verneuil, edge-defined film-fed growth, or heat exchanger processes. The selected method depends on the required crystal size, optical quality, cost, and final application.

Sapphire Windows vs. Glass and Fused Silica

Property	Sapphire	Optical Glass	Fused Silica
Scratch resistance	Excellent	Moderate	Good
Mechanical strength	Very high	Moderate	Good
High-temperature use	Excellent	Limited to moderate	Excellent
Optical behavior	Birefringent	Generally isotropic	Isotropic
Typical applications	Harsh-environment windows, sensors, lasers, semiconductor substrates	General lenses, windows, and imaging systems	UV optics, photomasks, high-purity optical systems

What Are Sapphire Waveplates?

Sapphire is a birefringent material, meaning that its refractive index varies with polarization and propagation direction. This property allows specially oriented and precisely polished sapphire plates to modify the polarization state of light.

Sapphire waveplates may be designed as quarter-wave or half-wave components for visible, near-infrared, or infrared optical systems. Their hardness, chemical resistance, and thermal durability make them useful in high-power lasers, industrial optics, spectroscopy, and demanding laboratory environments.

How to Specify a Sapphire Wafer or Window

To receive the most accurate sapphire substrate recommendation and quotation, provide as many of the following specifications as possible:

Diameter, length, width, or custom dimensions
Thickness and thickness tolerance
C-plane, A-plane, M-plane, R-plane, or custom orientation
Orientation tolerance or off-cut angle
Single-side polished, double-side polished, lapped, or unpolished finish
Optical polish or epi-ready surface requirements
Total thickness variation, bow, warp, and flatness limits
Surface roughness or scratch-dig requirements
Anti-reflective, metallized, dielectric, or other optical coatings
Dicing, edge shaping, drilling, beveling, or custom fabrication
Required quantity and target application

Need Sapphire Wafers or Optical Windows?

UniversityWafer supplies sapphire substrates for GaN epitaxy, graphene deposition, LEDs, RF electronics, photonics, lasers, sensors, semiconductor research, and harsh-environment optical systems. Standard research quantities and custom sapphire wafers up to large diameters are available upon request.

Browse Sapphire Wafers Online or send your dimensions, orientation, thickness, polish, coating, and quantity for a custom quote.