In 1821 Josef Fraunhofer (1787–1826) was the first scientist to conduct experiments on the diffraction of light on optical gratings which he virtually "rediscovered" for this purpose. The American astronomer David Rittenhouse (1732–1796) had already produced the first grating with a four-slit arrangement as far back as 1785. In 1882 the gratings, which were produced by mechanical means only (Fraunhofer himself used wires), were decisively improved by H.A. Rowland (1848–1901) in terms of the degree of precision that they offered. In addition to the theoretical discoveries in the field of physics made during this period, he also initiated new developments in the application of gratings. To this very day, however, the production of mechanically ruled gratings is still extremely time- and cost-intensive and requires the ultimate in precision engineering skills.
The first grating ruling engine for 30 x 30 mm gratings was probably set up in a design office at ZEISS in Jena around 1925. The first verifiable record of a grating ruled at ZEISS dates back to 18 January 1938. This was the day when the 101st ruling was performed by a modified Rowland-type ruling engine. After the end of World War II in 1945, and the subsequent partition of Germany and ZEISS, many products were developed in parallel in the two ZEISS companies in West and East Germany. And this also applied to grating manufacture in the decades to follow. During the 1950s, the first endeavors to set up grating production facilities were made in both Jena and Oberkochen as the first ruling engine was no longer available.
In Jena a new grating ruling engine (GTM I – Rowland type) was developed in 1951. This GTM I featured two all-time firsts: the moving slides were supported by an oil pressure mount, and the stepping switch mechanism used a smooth stepping disk instead of a gearwheel. At the end of 1955 a reproducible relative diffraction efficiency of ≥ 70 % in the maximum on a diffractive area of 70 x 64 mm² was achieved for gratings with 651 L/mm ruled by the machine applying this stepping disk.
In 1955 the Oberkochen facility also began to set up ruling technology and construct ruling engines for diffraction gratings displaying a ruling length of 75 mm.
In the 1960s and 1970s the potential for producing mechanical master gratings was expanded at both ZEISS companies through the use of additional ruling engines. The improvements and innovations of the ruling engines built in Jena allowed the parallel ruling of up to 4 gratings, the production of gratings with a small groove density for the infrared range and of grating prisms (GRISMs). The produced gratings displayed a maximum diffraction efficiency of approximately 90 %. The vibration sensitivity of the last generation of ruling engines was so low that they no longer made any contribution to stray light.
With the ruling engines set up in Oberkochen it was possible to further increase the size of the ruled grating surface. Here, the first interferometric control of the ruling arm was also used, allowing highly precise spacing of the grating lines in order to minimize the stray light caused by "grating ghosts". The two ruling engines used today produce mechanically ruled gratings which embody the know-how and expertise of ZEISS in the field of precision engineering and represent the state of the art in industrial production.
After 1950 there was a constant increase in the demand for plane gratings for monochromators. In response to this need, ZEISS initiated the development of replication technology for gratings, parallel to the ongoing development of the ruling engines. Without any compromise in efficiency, this technology makes it possible to produce precision grating replicas with a very low level of stray light that reproduce the flatness of the master gratings. ZEISS is one of the few quality providers in this field.
The company's own internal development of ion gas lasers in Jena during the 1970s was accompanied by the development of a special type of gratings known as holographic gratings which are produced by using optical interference methods. Right from day one, scientific research and engineering work were sharply focused on customer
needs. This close collaboration ensured that rapid advances were achieved in the development, leading to extremely effective solutions. The mid1970s saw the start of work on the production of holographic blaze gratings and the development of patented replication techniques. Blaze grating replicas and widefield gratings have been produced
in series since 1980.
The dry etching technique used in Oberkochen for grating production in the early 1980s enabled the manufacture of gratings with extremely low stray light. The 1980s were marked by the increased development of holographic concave gratings.
After the reunification of the ZEISS plants in Oberkochen and Jena the know-how was gradually consolidated in the 1990s. The production of industrial grating replicas has been performed solely in Jena since the start of 2000. Until 2011,
Oberkochen and Jena operated independent master grating production facilities, with Oberkochen concentrating on special gratings for synchrotron and space applications. These activities culminated in the production of, for example, the gratings for the James Webb Space Telescope in Oberkochen.
Today, ZEISS offers mechanically ruled plane gratings as well as holographically produced plane and concave gratings at the highest quality level. The standard program includes the production of precision replicas and specially manufactured master gratings.
ZEISS offers all customers collaborative assistance in the development of specific grating solutions. This incorporates the entire know-how and expertise of ZEISS, all garnered over many decades of scientific and engineering work and all at the customer's fingertips.