19 Sep 2002
The pick of this week's hottest patent applications in the world of photonics.
• Corning has been granted a patent for allegedly the first photoblank substrate material ideally suited to 193 nm lithography. The company will use the material as the starting point for making photomasks -- the transparent optics that contain the pattern for writing integrated circuits.
"The material is more homogeneous in terms of both transmission and refractive index compared with existing products" said Christine Heckle, semiconductor materials development manager at Corning Specialty Materials. The substrate is also said to have low birefringence and good refractive index homogeneity.
These qualities give more consistent 193 nm exposures, according to Corning. "If the substrate beneath the pattern is more uniform, you'll get a more repeatable pattern from you exposure tool," says Heckle. Further details can be found in US patent number 6 410 192 B1
• Causing your laser source to melt down or even explode is something researchers usually like to avoid. This is not the case at Swedish firm Bofors Bepab though. The company is attempting to patent a self-destructing laser source that ignites explosive charges.
Detailed in international patent application number WO 02/073116, the company has come up with a way to assemble a laser within an explosive charge. With the present invention, a very small laser source can now trigger explosives, claim the researchers in their application. In the past, a powerful laser source remote from the explosive has been required.
• Sony is trying to patent a diffraction lens element that has the optical properties of both a random phase plate and a lens array. When used in tandem with a laser, the element is said to reduce the number of speckles in the output. The invention is the subject of international patent application number WO 02/073249
Jacqueline Hewett is news reporter on Optics.org and Opto & Laser Europe magazine.