29 Oct 2002
The pick of this week's hottest patent applications in the world of photonics.
• Title: Method for imaging and spectroscopy of tumors and determination of the efficacy of anti-tumor drug therapies
Applicant: John Hopkins University, US
International application number: WO 02/082988
Clinicians treating skin cancer and lesions could benefit from an infrared imaging method being patented by US scientists. The technique, developed at John Hopkins University in Baltimore, relies on taking multiple infrared images before, during and after heating or cooling of the tumor. Apparently, the intensity distribution of the images relates to the tumor's metabolic activity and can be used to determine its shape and size. By comparing the images taken before and after medical treatment the success of the therapy can be assessed.
• Title: Method for reducing speckle
Applicant: STN Atlas Elektronik, Germany
International application number: WO 02/084380
The speckling that plagues the appearance of objects illuminated by laser light, may not be an annoyance for much longer thanks to a German scheme. Researchers at STN Atlas Elektronik of Bremen say that the way to reduce the effect is to use a laser with a sufficiently small coherence length and to cover the illuminated object with an even layer of a "volume scattering material". By carefully selecting the thickness of the layer to suit the laser's characteristics the speckle may be reduced to a desirable level.
• Title: Method and device for generating extreme ultraviolet radiation in particular for lithography
Applicant: Commissariat a L'Energie Atomique, France
International application number: WO 02/085080
Firing a laser beam into a dense mist of tiny droplets of liquid xenon is a way to make extreme ultraviolet (EUV) radiation, according to a patent application filed by the French atomic energy authority (CEA). The application states that the liquid xenon must be held at a pressure between 5 x 105 Pa and 50 x 105 Pa and a temperature of between -70 and -20 °C before being passed into a chamber through a small nozzle. Sources of EUV light will be needed for future semiconductor lithography equipment that will fabricate silicon chips will smaller and smaller feature sizes.
• Title: Irradiation device, particularly for carrying out photodynamic diagnosis or therapy
Applicant: Susann Edel and Georg Knott, Germany
International application number: WO 02/083237
A device for generating uniform high-intensity illumination of a surface, such as skin, for example, is outlined in the international patent application WO 02/083237. A series of flat reflecting segments are arranged in a hemispherical pattern above the surface and equipped with an array of LEDs or laser diodes. Even though the each individual segment features a relatively low intensity of radiation, the combined effect is homogenous strong irradiation of the surface. The applicants say that the device particularly suits photodynamic therapy (PDT) for clinical applications.
Oliver Graydon is editor of Optics.org and Opto & Laser Europe magazine.