IR Lenses

Infrared lens
A lens acts as a converging or diverging device based on the principle of refraction of light.

The History of Lenses

The oldest artifact is a quartz lens excavated in Nineveh, Mesopotamia, about 640 BC. European written records about lenses first appeared in ancient Greece. In Aristophanes’ play Cloud (424 BC), it was mentioned that burning glass (a convex lens that can gather sunlight to ignite); The earliest written record of lens in China is Mozi in the Warring States period, which describes the imaging law of lens. The book was completed in the 4th century BC. The invention time of the East and the West is almost the same, cheering for human civilization.

Infrared lens

Infrared imaging optics is the process of collecting light signals through a set of lenses onto a detector, which converts the light signals into electrical signals and generates digital or image signals, also known as photoelectric conversion. Different imaging usage scenarios require the selection of different detectors, as well as the corresponding selection of suitable infrared lenses. Different optical materials should be selected based on the lens design.

Common substrates for infrared lenses:

Silicon, germanium, Zinc selenide, Zinc sulfide, Calcium fluoride, Magnesium fluoride, chalcogenide glass

When selecting materials, multiple factors need to be considered:

1. Optical performance: refractive index, transmission band, transmission rate, etc

2. Physical properties: hardness, fracture coefficient, thermal diffusion coefficient, laser damage threshold, etc

3. Material production and processing factors: material growth difficulty, size and thickness limitations, batch processing difficulty, and blank cost

Therefore, the outermost piece of mainstream infrared lenses nowadays usually uses silicon and germanium as the main mirror because silicon and germanium materials are relatively hard and not easily broken, and the material growth technology is more mature, and the price is also more suitable. Internally, fluoride, Zinc sulfide, Zinc selenide, etc. are usually used for optical design to eliminate aberrations, improve light transmittance, resolution, etc., and the material price is relatively expensive. For some lenses with high commercial usage, Chalcogenide glass is usually used. The growth cost of Chalcogenide glass by molding is very low, and it can also be directly molded into an aspherical surface, reducing lens volume, and improving imaging quality, which has certain advantages.

The difficulty in processing infrared lenses compared to traditional visible light lenses lies in

1: The material is relatively soft, making it difficult to achieve surface quality.
2: The material is prone to deformation and the surface figure is difficult to control.

Based on years of accumulated optical knowledge both domestically and internationally, Anticipation Photonics has absorbed experience across industries and fields, and has developed a suitable processing system that can efficiently process high-quality infrared lenses in batches.

  Anticipation Batch processing Specifications