At which wavelength does the ruby laser produce light?

The ruby laser produces light at a wavelength of 694 nanometers (nm). This wavelength falls within the red portion of the visible spectrum. The ruby laser utilizes a synthetic ruby crystal as its gain medium, which is comprised of aluminum oxide (Al2O3) doped with chromium ions. When the chromium ions are electrically or optically excited, they emit light at this specific wavelength through a process called stimulated emission. This property makes the ruby laser particularly effective for various applications in dermatology and photography, particularly since the wavelength corresponds to the absorption peaks of certain chromophores in the skin, making it valuable for targeted treatments.

The other wavelengths mentioned, like 532nm (green light), 1064nm (near-infrared), and 755nm (near-infrared), are characteristic of different types of lasers, such as the Nd:YAG (neodymium-doped yttrium aluminum garnet) laser and the alexandrite laser, but they do not apply to the ruby laser. Each laser type is designed to emit light at specific wavelengths for various therapeutic and cosmetic uses, thus solidifying the distinction of the ruby laser’s unique wavelength.