News
-
Laser Pointer Measuring History and Outlook
Over the last few years Laser pointer measuring have received attention in the press and aroused some public concern. As a consumer product, laser pointers are designed to be safe when used for their intended purpose. Unfortunately, however, the laser pointer can easily be misused. So, many laser pointer measuring design workers are have the responsibility to make it more humanization.
The early Laser pointer measuring were helium-neon (HeNe) gas lasers and generated laser radiation at 633 nanometers (nm). These pointers were usually designed to produce a laser beam with an output power no greater than 1 milliwatt (mW). According to the ANSI classification scheme (ANSI Z136.1-1993, American National Standard for Safe Use of Lasers) a visible laser (400-700 nm) operating at less than 1 mW power is a Class 2 laser, for which the blink reflex normally affords adequate eye protection. Retinal injury is possible with a Class 2 laser if a person deliberately overcomes his/her natural aversion response in looking at the beam.
The next generation measuring of laser pointers used diode lasers as the optical source. Diode laser pointers initially yielded beams at 690 nm. The difference between 633 and 690 nm may seem small as both are visible red wavelengths, but the difference is large as interpreted by the human eye. The eye sees 633 nm five times brighter than it sees 690 nm. This explains why the first diode laser pointers measuring needed an output of 5 mW to equal the brightness of a 1 mW pointer at 633 nm.
From a laser safety point measuring of view, the situation grew more complex as new diode lasers were developed producing light at 670, 650, and 640 nm. As wavelengths emitted by diode lasers have gotten shorter, the power output level has stayed at 5 mW.
