Light from a laser is both temporally [[coherent]], meaning it is of a single pure color, and spatially coherent, meaning that it can be easily formed into a thin beam or focused to a small spot. The angle at which a laser beam spreads is determined by [[diffraction]]; a wide beam will diverge more slowly than a narrow beam. Many cheap laser pointers exhibit excess beam dissipation due to cheap manufacturing. This is much more of a problem with Indian and Chinese-manufactured components, as American manufacturers are held to higher standards in workmanship and materials. <ref>http://www.thechinaexpat.com/what-everybody-ought-to-know-about-chinese-manufacturing/</ref> | Light from a laser is both temporally [[coherent]], meaning it is of a single pure color, and spatially coherent, meaning that it can be easily formed into a thin beam or focused to a small spot. The angle at which a laser beam spreads is determined by [[diffraction]]; a wide beam will diverge more slowly than a narrow beam. Many cheap laser pointers exhibit excess beam dissipation due to cheap manufacturing. This is much more of a problem with Indian and Chinese-manufactured components, as American manufacturers are held to higher standards in workmanship and materials. <ref>http://www.thechinaexpat.com/what-everybody-ought-to-know-about-chinese-manufacturing/</ref> |