Sensor developments

For sensory applications and optical components, we develop customer-specific single-crystal garnet films. These are based on bismuth substituted rare earth iron garnet with stoichiometry (Bi,RE)3(Fe,Ga)5O12. The garnet films are deposited by liquid phase epitaxy (LPE) on 1 inch (R&D level) and 3 inch (production level) gadolinium gallium substrates (Gd3Ga5O12). Perfect single-crystallinity and low crystal defect density ensure high quality films for optical applications.

Generally, the already developed magneto-optical sensor types (A to D) have the following properties:

Specific Faraday rotation: 1 to 1.5 °/µm
Operating temperature range: 23 ± 8 °C for all types, type C also cryogenic
Magnetic dynamic range: 0.05 bis 140 kA/m
Sensor chip sizes: 8 x 8 mm, 20 x 15 mm (typ.)
Local resolution: 1 to 30 µm (system dependent)
Sensor total thickness: 0.5 mm
Transmission range (VIS): λ > 530 nm

There are differences in magnetic anisotropy. The sensor types A and D (bias) have an out-of-plane anisotropy. In contrast, types B and C have a predominant in-plane anisotropy.


Sensor design
Depending on the field of application, mirrors with adapted properties are applied to the magneto-optical films and optionally provided with a scratch-resistant layer. Sensor design is essential to achieve a high Faraday effect and the best possible spatial resolution.

Special developments
Due to the complete in-house production of magneto-optical films, we can develop special garnet films according to customer requirements. The following properties, for example, can be realized:

Film thickness: 0.5 to 10 µm (typ.)
Faraday rotation: 0.5 to 15 deg (polar)
Anisotropies: Out-of-plane (low and high uniaxial), in-plane
Chip sizes: greater than 3 x 3 mm to a maximum of 60 x 45 mm

We would be pleased to provide you with further information in response to your enquiry, and to submit an R&D offer with regard to a special development.

Dr. Carsten Dubs

Team Leader
Crystalline Materials


Phone: +49 3641 282564