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The reason for the high price of green pointers as compared with red lays in their additional internal complexity. They use a battery powered laser diode controlled by a miniaturized circuit, just like the red ones. However, the diode uses about five times the power of the red ones and emits it's laser light at an invisible, infrared wavelength of 808nm. The infrared laser output is focused into to a small crystal of Neodymium which then lasers at a longer wavelength of 1064nm. The 1064nm output beam is absorbed in an adjacent crystal of Potassium Titanyl Phosphate which resonates at twice the pump light frequency to produce an output of 532nm green laser light. A multilayer interference filter removes residual infra-red light, and the output is focused and collimated into a thin parallel beam. Both of the crystals are artificially grown, and must be cut, polished, and multi-coated to very small tolerances. Only a handful of companies are producing these crystals now. Each Howie Glatter SkyPointer™ is hand tuned for at least 10mw output, tested and sealed before shipment. I believe they are the highest quality green pointers on the market. They are constructed of strong metal tubing with a pocket clip. The SkyPointer™ 10mw lasers are significantly brighter than the glut of less than 3mw lasers found from most astronomy retailers at the same price. The SkyPointer™ is powered by two AAA alkaline cells. They work very hard when the pointer is on, supplying about 280 milliamps. The theoretical pointer on time is two to four hours at average drain, but if used frequently, with long on times, the battery lifetime will be somewhat less. They come with one set of batteries, in a hinged black metal presentation case. They are warranted against defects for six months. Temporaly out of stock |
The
Howie Glatter SkyPointer™ green laser pointer is a new
variation of an old idea that amateur astronomers have practiced
for many years : a narrow-beam high power flashlight has
been used to point out celestial objects. Tiny particles of
dust, pollen, and moisture scatter back enough light from the
beam to produce a visible line in the air. If the beam extends
far enough, a designated location on the sky can be
unambiguously pointed out. Nowadays, with increasing interest in
science and astronomy education, and the growth of astronomy
clubs and star parties, the SkyPointer™ provides a
convenient and practical way to show and teach celestial
geography.