Optatec 2022: LZH showcases its optical manufacturing breakthroughs…

20 Oct 2022

…and Edmund Optics and Schott expand partnership to provide filter glass in China.

Laser Zentrum Hannover (LZH) has this week presented what it calls “future technologies of industrial optics” at Optatec 2022, which has been taking place in Frankfurt, Germany.

LZH’s Department of Optical Components presented its latest research activities as well as its service and product portfolio at the international trade fair for optical technologies, components, and associated manufacturing systems. There were three main exhibits on its booth:

• Spatial ALD: The rotating ALD concept with plasma activation allows faster coating of optics. The technology enables more efficient production of optically conformal coatings on a wide variety of surfaces and optical geometries.
• Miniaturized filters: Whether in telecommunications, quantum technologies, or life science, such miniaturized filters have many applications. The production of thin-film filters without a substrate enables the manufacture of extremely small and very compact optics, for example for photonic integrated circuits.
• Multi-radius broadband monitor (BBM): This monitor allows optics to be coated precisely, efficiently, and reproducibly. LZH presented a new concept with multiple radii for improved process control.

In depth interview

optics.org visited the LZH booth and interviewed Tammo Böntgen, who is Head of Coatings Group at the center’s Optical Components Department.

“Considering the miniature filters, which are based on substrate-free coating materials, what we have done is use traditional ion beam sputtering (IBS) to coat a substrate; we then take off the coating itself from the substrate by chemical separation,” Böntgen said. “Then we cut the 30-40 micron layer of coating into tiny tiles. These can be used as, for example, optical filters in telecoms applications between sections of optical fibers. The coating materials that become the filters are typically combinations of oxides of silicon, hafnium, tantalum and titanium.”

“Inserting a tile is better and easier than trying to coat the end of the fiber. Conventional telecom fiber joints made with coated fiber ends also have a relatively high loss at the joint so using our tiles as optical filters is more efficient.” He added, “LZH is one of the very few companies that can do this because it is such a technical challenge. Our approach enables both better quality control and mass production.”

Another related project underway at LZH is to deposit such coatings directly onto the end of an optical fiber without losing the vacuum in the coating chamber; the challenge here is just to coat the fiber end – not the whole section of fiber that can be up to several meters long. Böntgen said this aim is currently a proposed IGEL research project with LZH and potential partners, due to start in 2023. “Such a capability would have applications in telecoms but also in endoscopy for bio-imaging and in anti-reflective coatings, and for example, in chip inspection,” Böntgen said.

Recently, LZH acquired an Atomic Layer Deposition (ALD) system from Finland-based supplier Beneq. Böntgen said, “The typical ALD machine is rather slow so we are working to make it faster and to make it compatible with other ALD semiconductor processes, and adapt it for optical coating purposes.

“With traditional surfaces such as spherical coating systems there is usually a bias towards one side or area that receives a thicker coating but we are aiming to make the coating process delivery material evenly all over the target shapes, such as onto a sphere or inside a cylinder.”

Edmund Optics and Schott to provide filter glass in China

Edmund Optics and Schott have announced the development of their strategic partnership to provide customers in Asia easy access to high-quality optical glass filters. The partners stated that “in-region inventory speeds up the delivery of standard filter types and sizes while in-region support simplifies the process for sourcing custom filters tailored for specific applications.”

The companies first partnered in 2020 to ease access to Schott’s materials in Europe, and the recent expansion of this partnership now brings these benefits to customers in China and all across Asia. The local inventory and flexible solutions allow optical system designers to minimize lead times, select from a range of standard options, and customize filters for their needs. Both Edmund and Schott can now leverage each other’s supply chains to support the filter glass market in China.

An inventory of 58 types of Schott filter glasses will be kept in stock and are available in 12.5mm, 25mm, and 50mm round and square sizes. Custom sizes can also be cut to meet particular needs.