26 Nov 2002
The pick of this week's hottest patent applications in the world of photonics.
• Title: Four kHz gas discharge laser system
Applicant: Cymer Inc, US
International application number: WO 02/093699
Are you looking to extend the repetition rate of your excimer laser? If so, the invention described in application WO 02/093699 could be one to watch out for. A fan clears the debris from the discharge region of the gas chamber between consecutive pulses. The patent claims that this allows a laser, such as an ArF laser, to operate with a pulse rates of 4000 Hz and at pulse energies of 5 mJ or greater. To maintain these specifications, the invention relies on customized software to control both a tuning mirror and the charging voltage.
• Title: Methods for laser treatment of soft tissue
Applicant: Laserscope, US
International application number: WO 02/091935
A method to treat soft-tissue, such as the prostate gland, with a solid-state laser is described in international patent application WO 02/091935. An optical fiber terminating in a side-firing probe carries the output of a laser to the target tissue. Operating with pulse duration between 0.1 and 500 milliseconds, the application says these pulses quickly char the target tissue, which increases ablation rates and reduces treatment time.
• Title: Nitride semiconductor LED with tunnel junction
Applicant: Emcore Corporation, US
International application number: WO 02/093658
A layer structure being patented by Emcore could lead to LEDs with better illumination uniformity. A tunnel junction that is sandwiched between two p-type regions spreads the charge over the device and improves the light emission. In addition, the nitride-based LED does not require a transparent electrode in contact with the p-type semiconductor.
• Title: Device for optimization of the thickness of an ice layer
Applicant: Kalannin Kaspek, Finland
International application number: WO 02/093106
A Finnish firm is attempting to patent an idea to optimize the thickness of an artificial ice sheet, such as those at ice hockey rinks. A laser, mounted on an ice-resurfacing machine, fires a beam at the ice sheet. A receiver on the resurfacing machine then regulates the position of the scraper blade to keep the ice-sheet thickness constant.
Jacqueline Hewett is news reporter on Optics.org and Opto & Laser Europe magazine.