Electricity is usually used in a laser to excite the electro

Electricity is usually used in a laser to excite the electrons to the metastable state. Could we use temperature instead? Consider the HeNe laser describe in the text (figure 30.39). What temperature gas would be required so that the kinetic energy of the atoms would be enough to excite the helium atoms from the ground state to the “first” level in figure 30.39? What does your answer suggest about the feasibility of using temperature to power a laser?

emerge as laser light. Diode lasers eai ow light to bounce back and forth and a tiny fraction to iwatt range. Collision transters energy First Metastable 20.61 ev 20.66 ev Ground state Helium Neon ium and neon. In the cammon helum-neon laser, an electrical discharge pumps energy into the metastable s e helium asoms than neon atoms. Excled helium atoms easily de excite by transterring energy to nean in a co thy the neon to occur

Solution

Answer:

Temperature needed to excite the atom from ground state to first corresponding to 20.61 eV

(3/2)kT = 20.61 x 1.6 x 10^-19 joule

T = (2/3)*(20.61 x 1.6 x 10^-19) / (1.38 x 10^-23) = 159304 K

Such a huge temperature value we can not expect in imagination, even though only 20.61 Volt is needed to an electron in excited state.

In laboratory such a huge temperature can not be possible