Kathy, IEC 825-1 has been published as EN 60825-1. EN 60825-1 covers lasers and LED's. An LED and a laser are two different devices, so I don't think that I can tell you the circumstances under which an LED "becomes" a laser. Theoretically, this would only happen if the piece of semiconductor used for the LED were cleaved to the proper dimensions in order to make a reflective cavity ... But I don't think that that's what your asking, so I'll spare the details.
What I can tell you is that EN 60825-1 deals with safety and exposure limits of light radiation. The standard covers both lasers and LED's and really doesn't care if the light source is a laser or an LED. As a matter of fact, the beginning of the standard goes so far as to mention that it will use the word "laser" to cover both "laser" and "LED" for the remainder of the text. The standard is concerned with semiconductor light sources that have the potential to concentrate enough light power into a small enough area to either cause eye damage, skin burns, or fire hazards. This includes both lasers and LED's. It doesn't matter what it's called. What matters is how much power it puts out and how small an area this power is focused into. I'll give you some examples: We manufacture fiber optic light sources which inject infra-red(1550nm) light into a fiber. We have one model that uses a laser to generate the light and another which uses an LED. We have gone through the calculations outlined in the standard, and both are Class 1 devices. We label both as a Class 1 laser device under EN 60825-1. We then put certain warnings in the user's manual ... We manufacture another product which uses an LED to inject red (635nm) light into a fiber. The red LED by itself wouldn't be a problem, however, our product collimates and focuses the light from this LED into the core of a fiber (10um diameter). The power density of red light in this fiber is calculated to be high enough for us to classify this device as a Class II laser device under EN 60825-1. We put the appropriate warnings in the user's manual. We make another product that uses a red LED on its display in order to show that the power is turned on. The light from this LED is unfocused and diffuse. As such, its power density is low enough that we don't even consider EN 60825-1. The unit is unmarked (from laser classification standpoint) and we put no warnings regarding laser radiation in the manual. One special consideration in EN 60825-1 is for "arrays" of LED's. A single, diffuse, unfocused LED by itself may be harmless. But there are circumstances where people will design products with an array of many LED's close enough together that they will put out sufficient power density to be a concern. Chris Maxwell, Design Engineer GN Nettest Optical Division 6 Rhoads Drive, Building 4 Utica, NY 13502 PH: 315-797-4449 FAX: 315-797-8024 EMAIL: [email protected] > -----Original Message----- > From: Kathy Toy [SMTP:[email protected]] > Sent: Thursday, October 05, 2000 1:09 PM > To: [email protected] > Cc: [email protected] > Subject: When is an LED a Laser? > > > > > Hi: > > Our design engineers are using LED more often and > have been asked if the LED are approved by IEC 825. > > My question: When is an LED a Laser? In other > words, at what power level does an LED become > required to meet the IEC 825 standard? Are there > industry limits for specific LEDs? > > It seems that in the past LEDs were basicly ignored > except for color issues. What is the current > thought or rule on this issue? > > Thanks in advance, > kt > > > > > > _/_/_/ _/ _/ _/ _/ Kathy Toy > _/ _/ _/ _/_/ _/ Safety Compliance Engineer > _/_/_/ _/ _/ _/ _/ _/ Office/Voice > Mail:(650)786-3210 > _/ _/ _/ _/ _/_/ Dept. FAX: (650)786-3723 > _/_/_/ _/_/_/ _/ _/ Email:[email protected] > > > M I C R O S Y S T E M S > > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: [email protected] > Michael Garretson: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
