Due to their high hardness, excellent optical performance and chemical stability, sapphire lenses offer significant advantages in the manufacture of optical devices. The following analysis outlines the specific applications and advantages of sapphire lenses in optical devices.

1. Medical field

(1) Endoscope and microscope lenses

Sapphire lenses are renowned for their high hardness and abrasion resistance, making them an optimal choice for medical devices such as endoscopes and microscopes. During surgery or testing, the lens needs to come into frequent contact with human tissues or chemical reagents. The scratch resistance and corrosion resistance of sapphire can ensure clear imaging over long-term use and reduce wear and tear to equipment.

(2) Laser surgery window

In laser medical equipment, sapphire is used as the laser window material. This material efficiently transmits laser beams (such as in the ultraviolet to near-infrared bands) while withstanding high temperatures and mechanical shocks. This ensures the accuracy and safety of the surgery.

(3) Biosensors and imaging systems

The technology of sapphire metallization (surface deposition of metal film) endows the substrate with both electrical and thermal conductivity, making it suitable for use in electrical connections and thermal management in biosensors. Additionally, its high reflection performance has the potential to enhance the image quality of high-resolution medical imaging systems and extend the service life of the equipment.

2. Consumer electronics

(1) Smartphone camera protection lens

Sapphire lenses are renowned for their scratch resistance and are used in mobile phone camera protection covers. This effectively mitigates the impact of daily wear and tear on image quality.

(2) Smartwatch crystal

Sapphire crystal has become a standard feature of wristwatches. It exhibits a Mohs hardness of 9, which endows it with the capacity to resist scratches inflicted by hard objects, such as keys and sandpaper. This property is accompanied by its ability to maintain light transmission and to enhance the display effect.

3. Aerospace industry

Sapphire demonstrates excellent performance in space. Its high-temperature resistance, radiation resistance and chemical stability render it an optimal window material for satellite optical detection equipment, thereby ensuring stable operation under harsh conditions.

4. Scientific research and industry

(1) Laboratory optical components

Sapphire lenses find application in scientific research instruments, such as lenses and windows. Their wide spectral transmittance (extending from the ultraviolet to the infrared spectrum) and chemical inertness renders them well-suited to scenarios such as chemical analysis and spectral detection.

(2) Semiconductor fabrication

Sapphire, when utilized as a substrate material for LEDs, has been shown to enhance the photoelectric efficiency and service life of LED devices. This enhancement is attributed to the high thermal conductivity and electrical insulation properties inherent to sapphire. Furthermore, sapphire substrates are utilized in the fabrication of gallium nitride (GaN)-based power devices and high-frequency communication devices, thereby supporting the emerging industries of 5G and electric vehicles.

Sapphire lenses offer significant technological benefits, however their high manufacturing cost and complexity in production, specifically the requirement for precise control of the uniformity of the metal film, present substantial obstacles to wider implementation. Advances in technology and large-scale manufacturing processes are anticipated to result in a decline in costs, thereby fostering its dissemination in domains such as medical optics and consumer electronics. This development is set to position it as a pivotal material for optical devices.