Researchers at the Technion – Israel Institute of Technology have developed a ‘faster, cheaper method to produce customized optical components’ for applications including ‘corrective lenses, augmented and virtual reality, autonomous vehicles, medical imaging and astronomy.’ As DIY Photography observes, it’s not unreasonable to think that the new lens making method could be used for photographic lenses, at least during development and prototyping.
Optical lenses come in many different shapes and sizes. The more complex a lens, the more difficult and costly it is to develop and produce. Specialized equipment is required. At Technion – Israel Institute of Technology, the team has developed a way to shape curable liquid polymer. The method can be used for making large optics, which has proved challenging for other similar methods.
‘Our approach to making freeform optics achieves extremely smooth surfaces and can be implemented using basic equipment that can be found in most labs,’ said research team leader Moran Bercovici from the Technion – Israel Institute of Technology. ‘This makes the technology very accessible, even in low resource settings.’
|Lens manufacturing in progress. Credit: Technion – Israel Institute of Technology|
Bercovici and colleagues have published their research in Optica, and it shows that the technique can be used to fabricate freeform optical components with sub-nanometer roughness in mere minutes. It’s even faster than other prototyping methods, such as 3D printing.
Omer Luria, a contributor to the research paper, said, ‘Currently, optical engineers pay tens of thousands of dollars for specially designed freeform components and wait months for them to arrive. Our technology is poised to radically decrease both the waiting time and the cost of complex optical prototypes, which could greatly speed up the development of new optical designs.’
|The research team has used its method to create a variety of freeform optics, including lenses up to 200mm in size. Credit: Technion – Israel Institute of Technology|
The researchers began work on the new method after learning about the 2.5 billion people worldwide that need corrective lenses but lack access. Valeri Frumkin, who first developed the method in Bercovici’s lab, said, ‘We set out to find a simple method for fabricating high quality optical components that does not rely on mechanical processing or complex and expensive infrastructure.’ The team then realized that the method could be used for far more complex optical topographies, ones that have traditionally been extremely expensive and timely to create and required specialized equipment.
A primary challenge of making optics by curing a liquid polymer is that as you increase the size of optics beyond about 2mm, gravity overcomes the surface forces, and the liquid flattens. To overcome this challenge, the team developed a way to make lenses by using liquid polymer that is submerged in another liquid. The buoyancy works against gravity, allowing surface tension to do its job.
|From left to right, Mor Elgarisi, Prof. Moran Bercovici and Omer Luria. Credit: Technion – Israel Institute of Technology|
With gravity dealt with, the team could craft smooth optical surfaces. When you have created the required topography of the optical element, using UV exposure, or other methods, cures the liquid polymer. So far, the team has successfully fabricated a wide variety of shapes and sizes of optical lenses, with sizes up to 200mm and shapes such as trefoils.
The research paper’s lead author, Mor Elgarisi, said, ‘We identified an infinite range of possible optical topographies that can be fabricated using our approach. The method can be used to make components of any size, and because liquid surfaces are naturally smooth, no polishing is required. The approach is also compatible with any liquid that can be solidified and has the advantage of not producing any waste.’
|Mor Elgarisi. Credit: Technion – Israel Institute of Technology|
It’s easy to imagine the possible applications for such technology. Beyond improving people’s lives by making corrective optics more accessible, the method could also allow small labs and businesses to work more efficiently, thus driving innovation. Perhaps the method could even be used for prototyping camera lenses.