« Last post by evan_au on Today at 05:09:06 »
Quote from: OP
Is it even possible to produce these colors in a laser diode?A laser beam is defined as being a single wavelength coherent light. So a laser can produce pure "rainbow" colors, but not "mixed" colors like brown, cyan or magenta.
In practice, lasers do not produce exactly one wavelength - they typically produce several closely-spaced wavelengths, which are a submultiple of the length of the laser cavity. But these wavelengths are still so close together that the human eye cannot distinguish them.
Where high spectral purity is important (eg long-distance telecommunications), you can couple a second cavity so that the selected wavelength is enhanced, and the unwanted wavelengths suppressed.
I work a lot with infra-red lasers, and these are not visible to the naked eye, nor would an ultraviolet laser be visible in a dark room. So in principle, these could be called "black" lasers, ie the absence of visible light.
I have visited an IMAX laser theater, where they mix light from red, green and blue lasers to produce a full range of visible colors, including white and brown.
Is it possible to create a laser that will produce a destructive interference wave pattern, so that it will dim out another laser?Yes, two lasers of the same wavelength will interfere constructively and destructively in different places.
Even one laser (like a common laser pointer) will interfere with itself - that speckled effect when you shine it on a painted wall is the interference effects of the laser beam interacting with itself to produce destructive interference on your eyeball. Fortunately, it is only destructive to the light, not your eyeball.
What is andersite ?Typo: It is a mineral ...sorry, you cannot view external links. To see them, please REGISTER or LOGIN
What would happen if you point a ultraviolet laser at a andersite crystal?This article will probably tell you, but it is behind a paywall:
...sorry, you cannot view external links. To see them, please REGISTER or LOGIN