Orange, Yellow, and Green Light from Red Laser Pointer?
While the lasing line from a diode laser or even a cheap laser pointer is quite narrow, there can be other wavelengths of incoherent light present in the beam. Since the effective aperture of the laser diode is nearly a point source (1×3 um typical), these spurious outputs will still collimate and/or focus nearly as well as the laser beam itself. However, it’s highly unlikely that any of these are actual lasing lines except very near the main (design) wavelength. No, you can’t convert a red laser pointer into a rainbow pointer with a simple modification performed on your kitchen table! 🙂 I’ve seen the existence of faint non-lasing light from more than one cheap laser pointer as well as from a “dead” red laser pointer where the laser diode had turned into an expensive LED. The orange, yellow, and green output was of similar intensity to the same spurious colors present in the lasing laser pointers so it is likely not related to high field intensities when lasing but due to impurities r
