In January of 2023, Inprentus debuted their unique blazed grating strategy for Augmented Reality waveguides at SPIE 2023 AR|VR|MR conference (link). Within the next 8 months, this small company from Champaign, Illinois has seen rapid engagement with more than 10 leading companies at the forefront of the Augmented Reality industry. “These companies, among the largest AR original equipment manufacturers, have gaps in their manufacturing solutions”, says Subha Kumar, the Chief Growth Officer at Inprentus. “Additionally, we are very excited about our developing partnerships with several high volume replicators, allowing us to be a one-stop shop for waveguides - from manufacturing of masters to delivering replicated lenses for smart glass manufacturers.”
Blazed grating structures have high spectral tunability, large angular bandwidth, are highly efficient, and are easy to replicate. The advantages of mechanically-ruled blazed masters over traditional e-beam lithography masters are many, and include: one technology for ruling all waveguide gratings, crossed (2D) grating capabilities, no screen-door effect, line-by-line control of diffractive properties, highly efficient blazed facets, and ease of scalability.
A key bottleneck in the manufacture of blazed waveguides involves a series of complex and expensive manufacturing steps using e-beam lithography. Inprentus elegantly addresses this bottleneck by employing a simple and unique nanoscale contact mode lithography technique called mechanical ruling as an alternative to e-beam lithography. The Inprentus technique is ideal for creating master diffractive optics used for prototyping as well as for high-volume replication. Inprentus’ mechanical ruling methods allow for multiple gratings – input, expander, and output – to be precisely oriented on a surface to create an AR waveguide using a single efficient manufacturing set-up.
Peter Abbamonte, Inprentus’ founder and professor of physics at the University of Illinois, noted “Our experience over the past ten years, as providers of high-value diffraction gratings for materials research, precision spectroscopy, and the semiconductor lithography market, has primed us to address the stringent requirements of the emerging AR market. Clearly, the Inprentus method presents a distinct manufacturing advantage for surface relief waveguides where one does not have to choose between performance and scalability”.
Inprentus offers established optics engineering services including complete optical system designs, RCWA and FDTD simulations, design-for-manufacturing services, manufacturing of masters in collaboration with a replication partner, and a full suite of metrology techniques.