Harmonel: Green Laser Frequency Doubling
Optics, Waves & Sound arc, page 121 of 193. Back to The Pixelated Physics Universe
Who they are
Harmonel has one line, and says it often: “Green pointer. invisible 1064 too.”
Harmonel is a character of the Optics, Waves & Sound arc: drawn in pixels, ruled by one piece of real physics, and never allowed to break it.
The physics
Cheap green 532 nm laser pointers are frequency-doubled 1064 nm (Nd:YVO₄) lasers, and some leak invisible infrared (808 nm diode pump light and 1064 nm) alongside the green.
$$ \begin{gathered} \omega_{\text{out}} = 2\,\omega_{\text{in}} \;\Leftrightarrow\; \lambda_{\text{out}} = \frac{\lambda_{\text{in}}}{2} \\ \frac{1064\ \text{nm}}{2} = 532\ \text{nm} \end{gathered} $$
| Symbol | Meaning | SI unit |
|---|---|---|
| $\omega$ | angular frequency | rad/s |
| $\lambda$ | wavelength | m |
Sources
Crossovers
Harmonel meets Specklorn (Laser Speckle). Harmonel's green pointer is coherent, so it speckles. Specklorn says that contrast of 1 is the mark of fully developed speckle.
Harmonel meets Beaconess (Laser Guide Star). Harmonel doubles infrared light to green in a nonlinear crystal. Beaconess needs sodium's yellow 589 nm light, and making it efficiently also uses nonlinear optics.
Wear the lore
Concept keywords: Green Laser Frequency Doubling, Harmonel, Optics, Waves & Sound, physics lore, Pixelated Physics