The thought of lasers in the classroom can conjur up images of mayhem... so Laser Classroom takes the safety of both you and your students very seriously. So seriously, that we have created an entire curriculum guide: Bringing STEM to Light, the Science, Technology, Engineering and Math of LASER Safety, including 4 lessons and a capstone project all about the science behind laser classifications and laser safety in general.
Most people are a little surprised to learn that all laser products, are regulated by the Food and Drug Administrations’ Department of Radiological Health and are governed by specific rules and regulations listed in the Code of Federal Regulations, 21 CFR 1040.10 and 1040.11. We work very closely with the FDA and ANSI to ensure that our laser products are in total compliance with all regulations.
Used responsibly, FDA approved lasers are extremely safe for use by adults and students under supervision in a classroom or laboratory setting.
Laser Classifications
The FDA classifies Lasers into several broad areas depending on the potential for causing biological damage. When you see a laser, it should be labeled with one of these class designations:
- Class I - These lasers emit laser radiation below known hazard levels.
- Class I.A. - This is a special designation that applies only to lasers that are "not intended for viewing," such as a supermarket laser scanner. The upper power limit of Class I.A. is 4.0 mW.
- Class II - These are low-power visible lasers that emit above Class I levels but at a radiant power not above 1 mW. Class II lasers are considered safe for use in classroom or other sensitive environments because a this low power, the eye's natural "look away" response is sufficient to protect from otherwise possible harm.
- Class IIIA – Lasers with a power output of between 1mW and 5mW can be hazardous only for intrabeam viewing – meaning if you point the beam directly into your eye, you can cause damage. Barring irresponsible use, class IIIA lasers are considered safe and the majority of pen-like pointing lasers, including those used for star pointing, are in this class.
- Class IIIB - These are moderate-power lasers.
- Class IV - These are high-power lasers (cw: 500 mW, pulsed: 10 J/cm2 or the diffuse reflection limit), which are hazardous to view under any condition (directly or diffusely scattered), and are a potential fire hazard and a skin hazard. Significant controls are required of Class IV laser facilities.
To read more about the FDA's regulations regarding lasers and laser pointers.
For more information and a fantastic video about the safe use of laser pointers as regards aircraft and the FAA .
Green Lasers and the IR Filter
Green Lasers are constructed using an Infrared Laser Beam that is passed thru a crystal medium to create 532nm visible light. The IR beam is not visible but can be dangerous, so most green laser pointers contain a filter to prevent the escape of the IR radiation. All of Laser Classroom’s green Laser products are equipped with an IR filter to protect users from potential harm.
Remember, lasers are not toys and they should only be used with adult supervision in a classroom or laboratory setting.
- Never aim or shine a laser pointer at anyone.
- Only activate the laser pointer when you are using it to point at a nearby object.
- Do not buy laser pointers for your children. Lasers are not toys.
- Before purchasing a laser pointer, make sure it has the following information on the label:
1) A statement that it complies with Chapter 21 CFR (the Code of Federal Regulations)
2) The manufacturer or distributor's name and the date of manufacture
3) A warning to avoid exposure to laser radiation
4) The class designation, ranging from Class I to IIIa. Class IIIb and IV products should be used only by individuals with proper training and for applications where there is a legitimate need for these high-powered products.
Lifetime of the Laser Diode
Several design factors impact the lifetime of the Laser Diode and therefore the reliability and life time of a Laser Classroom Laser.
- The Laser Classroom Laser Diode is protected by a cap and is packaged in a clean room with nitrogen. This cap and packaging process protects the laser diode from damage by dust or moisture.
- Both the laser diode and the crystal emit heat. By separating the two heat sources with the focus lens, a Laser Classroom Laser can dispatch heat more efficiently. This more efficient dispatch of heat protects the diode and increases its reliability and lifetime.
Reliability of Performance
Several design elements allow us to offer a Laser with reliability that exceeds that of lower cost Laser Pointers.
- The drive circuit for the laser is based on a photodiode feedback loop that monitors the optical output and provides a control signal for the laser diode. This maintains operation at a constant optical output level. Our low cost competitors' drive circuit operates the laser diode without a photodiode feedback loop, the laser diode is simply driven at constant current. This causes the optical output to fluctuate as the laser diode temperature changes. A Laser Classroom Laser Blox regulates power fluctuations in this way to ensure a consistently bright beam/dot.
- The Laser Classroom laser module, crystal and diode are aligned by experienced engineers who check several critical points during assembly to ensure reliability.