Europe, UK, Asia & RoW: [email protected] +44 (0)1622 859444 | USA & Canada: [email protected] +1 401-583-7846

BREXIT UPDATE: Knight Optical will continue to provide quality assured service for all your optical requirements both custom & stock. We will handle all requirements caused by the new regulations.


Looking For a Custom Optical Solution? Enquire

Custom YAG

Yttrium Aluminium Garnet, Y3Al5O12, more commonly known as YAG, is a durable, synthetic material that belongs to the garnet group. It is often used as a substitute for sapphire as it is has a similar transmission range and refractive index, but it is easier to polish and does not exhibit birefringence.
Below is a summary of YAG’s optical properties:

Transmission range

0.21 to 5.5µm

Refractive Index

1.81523 @ 1.06µm


4.56 g/cm3

Melting Point



Knoop 1215

Knight Optical can supply a variety of YAG optical components including windows, lenses, rods and YAG ground blanks. We can also provide uncoated and coated optics, with broadband antireflective (BBAR) coatings. Our typical manufacturing specifications are listed below, however we are always expanding our capabilities so if your requirements are not mentioned below please contact our technical sales team who will guide you through your enquiry.


< 5mm to 100mm

Form error (@633nm)

< 0.25 waves

Centration /parallelism

< 1 arc minute


< 20/10

Typical coatings

BBAR @ 3-5µm

DLC @ 3-5µm

Every component is individually tested by our highly skilled technicians in our state-of-the-art metrology lab to ensure all components meet our high quality standards. You can find out more about our testing capabilities here.
Contact our multilingual technical sales team and discover how Knight Optical’s high quality YAG optical components and service can improve your instrumentation and supply chain experience.

Additional Information

  • Crystalline YAG is grown via the Czochralski technique.
  • YAG crystal has good optical homogeneity across its transmission range and be used in in high temperature and high energy applications.
  • It is often used in place of sapphire, where durability is needed but sapphire’s birefringence is an issue. YAG shares similar mechanical and optical properties to sapphire, including its transmission range and a high refractive index, but it is not birefringent.

Typical Applications

Laser crystal
  • When YAG is doped with metals such as neodymium (Nd), thulium (Tm), erbium (Er), and chromium (Cr) it can be used as an active laser crystal. Undoped YAG cannot.
  • Nd:YAG is the most widely used active laser medium, with an operating wavelength of 1064nm. It is the medium in most solid state lasers that are used for scientific and medical applications, such as ophthalmology and laser spectroscopy.


Our 2022/2023 Catalogue

Inside Knight Optical’s catalogue you’ll find details of the industries we serve as well as the many other services we can offer. It also showcases hundreds of our most popular products, supported by useful technical information, to help you choose the right part for your application.
Click below to view our digital catalogue now.

view our catalogue