‘Highway’ to guide light through an optical chip
“We set out to integrate tiny optical components that can direct a beam of light, such as lenses and mirrors, into a single optical chip”
University of Technology Eindhoven reports on the research of David De Vocht and colleagues:
“Our eyes are passive; they capture light from our surroundings to identify objects. But active optical sensors emit (laser) light themselves. A lens then focuses this light on an object and you can use the reflected light to analyze the object. Such optical sensors are widely used in industrial processes to improve quality, safety and control. You can use them to detect dangerous particulate matter in the air, for example. They’re also crucial in semiconductor manufacturing. And there is an ever-increasing demand for more accurate measurements. That’s why we’re developing new technology that will allow us to make sensors smaller and more affordable for even more applications” – explaines David De Vocht.
So, what makes the type of sensors developed by De Vocht and his colleagues so innovative? “We set out to integrate tiny optical components that can direct a beam of light, such as lenses and mirrors, into a single optical chip. So, it’s everything miniaturized and on one single chip. The curved lenses you’re familiar with are not practical for such compact applications; they take up far too much space. So, the lenses are flat like pancakes with a thickness of only a few micrometers.”
Keep your lane
All of this is to be able to accurately direct the light beam, De Vocht explains. He compares it to a highway, where motorists can only go in one direction. “We tried to develop technology that optimizes the selection of on-ramps and off-ramps for smooth traffic flow.”
In the lab, De Vocht worked on an innovative solution to direct the light beam using optical couplers. He did not use regular lenses for this, but waveguide holograms.
“We send the laser light through a thin waveguide on our optical chips, like a highway for light. In it, we built a series of nanostructures that are smaller in size than the wavelength of the laser light. As a result, the usual principles of traditional optics no longer apply. The position of a nanostructure now determines in which direction the light is sent, while the thickness controls the light beam’s intensity. So, we have an ultra-thin component that prevents the light beam from scattering in all directions and keeps it on its highway lane. Another remarkable thing is that we can do this with different colors of light.” …. more
If you enjoyed this article, you will like the following ones: don't miss them by subscribing to :
