Calculating laser wavelength/power to cause emission of light in a gas?
Two-photon excitation using femtosecond lasers that emit in the infrared range is a technique used in living cell imaging via fluorescence microscopy. Advantages of the technique, such as the minimized light scattering (~ 1/$\lambda^4$) using long wavelength for excitation and the fluorescent dyes used are discussed here.

For large volumetric displays, a different technique was/is under development in a joint project of the Japanese National Institute of Advanced Industrial Science and Technology (AIST), the Keio University and an industrial partner.

Here, fluorescence does not play a role and special gases are not needed either.

The images can be displayed in air and are formed - pixel by pixel - by plasma dots generated in the focal point of pulsed infrared lasers with a pulse width of 1 ns and a repitition rate of 100 Hz.