Trends In Fiber Optic Beam Delivery For Materials Processing With Lasers

Lasers for materials processing are no longer an anomaly. Many industries now take lasers for granted as manufacturing tools. Carbon-dioxide lasers are still the most widely used, but Nd:YAG lasers have shown the fastest growth of technological improvement in recent years, and sales of these lasers are increasing rapidly.

by Thomas Kugler

The Optical Invariant

Sunbeams And Moonshine

Crepuscular rays are solar rays that are seen emanating from the horizon at twilight and spreading across the sky. They may be caused by clouds at or below the horizon, blocking some of the light path but allowing light to penetrate overhead in places. Similarly, a mountain range at or below the horizon may result in crepuscular rays, as the sun is blocked by the peaks and passed by the mountain passes. At other times during the day, one may see sunbeams breaking through holes in clouds or around the edges of clouds. Under these conditions, the sunlight breaking through the clouds is scattered toward the observer, and forms a contrast with those adjacent areas in which the sunlight is blocked.

by Janet Shields

Nintendo Surgery: Laparoscopic Techniques Increase In Popularity

Minimally invasive surgical procedures using the laparoscope are becoming extremely popular in general surgery. Ever since the first laparoscopic cholecystectomy (gall bladder removal) in 1987, a variety of intra-abdominal operations have been introduced. Laparoscopic procedures such as the cholecystectomy are preferred over conventional open surgery since the recovery time is substantially reduced.

by Michael Thomas

Industry Input Sought On Two New Activities

The Telecommunications Industry Association (TIA) has formed a new Multimedia Engineering Subcommittee, TR 41.5, to work on standardization issues related to systems architecture required to support multimedia at customer sites. The new committee will also act as the focal point for various multimedia projects in residential and commercial environments. According to subcommittee chair Jim Romlein, president of MIS Labs, key action items for the multimedia committee are determining "what the customer interface box will be," where it will stand at customer sites, and how it will support the transport layer and the many requirements of products and services developers. Some suggested areas for standardization include specifications for front and backend pieces and the card cage, according to Romlein.

by Marilyn Kornfeld

Color Confusion

On the 200th anniversary since John Dalton published “Extraordinary facts relating to the vision of colours; With observations,” the first scientifically presented, detailed observation on color vision confusion in inherited cases

by Odeda Rosenthal