19 Nov 2013 ZEISS has a long tradition in the design and manufacture of optical diffraction gratings for OEM spectroscopic instruments and laser applications. For the last 75 years ZEISS has developed comprehensive capabilities in the generation of master gratings, first by mechanical ruling, and later on by holographic recording.
Mechanically ruled gratings from Zeiss offer particularly uniform groove spacing with very low Rowland ghosts, resulting in low stray light. ZEISS has two state-of-the-art Rowland type ruling engines in operation, each producing a significant number of gratings each year. Grooves are produced by burnishing them individually with a diamond tool into a thin film of metal layer.
Holographic gratings are recorded by an interference field of two laser beams. The interference field is transformed into an actual spatial structure through a photoresist, which is supported by a nearly diffraction-limited quality polished substrate. In distinction to mechanical ruling, grooves may be either parallel or of unequal distribution in order to optimize optical imaging performance. Holographically produced gratings can be generated on flat as well as curved (concave/convex) substrates correcting aberrations. Holographic gratings can be produced with sinusoidal, binary or blaze groove profiles and are characterized by superior diffraction efficiency and stray light performance.
Both types of master gratings (ruled and holographic) allow replication of optically equivalent copies of the master. A variety of copying processes are established in order to produce volume quantities of consistent high quality at commercially sensible level. Depending on the application, customers can choose between master grating or replicas. Gratings from ZEISS are either available as standard grating, defined in grating configuration and size or custom made solutions. Custom made gratings are specifically designed and produced according to the customer’s unique technical requirements.
ZEISS gratings are typically used in OEM instruments such HPLC systems, Biomedical devices, Sensing instruments, Process control equipment, Laboratory spectrometer systems, Color analyzer, High energy lasers, Space flight instruments, Astronomy, only to mention a few applications.
The Zeiss product range comprises the following grating types:
Plane gratings
- Mechanically ruled blaze gratings
- Holographic blazed
- Holographic sinusoidal gratings
- Gratings optimized for Laser applications
- Grisms
Gratings on curved surfaces
- Aberration corrected concave Monochromator gratings
- Aberration corrected concave Polychromator grating
- Rowland Circle Gratings
- Convex gratings for different configurations, e.g. Offner-Spectrograph
Grating Manufacturing Capabilities:
Substrate type: Flat, concave and convex
Substrate material: Various glasses (e.g. N-BK7), Zerodur, Aluminum, as well as customer supplied materials
Substrate shape: Circular, square and rectangular shapes up to 270 mm in diameter
Groove density: 3 grooves/ mm to 7,200 grooves per mm (depending on groove profile)
Groove profiles: Blaze, laminar, sinusoidal
|