Question

Question: In a diode laser electrons dropping from the conduction band across the gap, and into the valence band produce the photons that add to the coherent light. The ZnTe laser has a band gap of 2.25 eV. About what wavelength laser light would you expect it to produce?

Short answer

Answer

The wavelength of the light is 551nm .

Step-by-step solution

Given data

The ZnTe Laser light has a band gap of 2.25eV

Concept of the energy of a photon

The energy of a photon is related to the frequency f is, $\mathit{E}\mathbf{}\mathbf{=}\mathbf{}\mathit{h}\mathit{f}$.

The frequency of a related to the wavelength is, $\mathit{f}\mathbf{=}\frac{\mathbf{c}}{\mathbf{\lambda }}$.

Here c is speed of light.

From the above two equations the resultant equation is, $\mathit{E}\mathbf{=}\frac{\mathbf{h}\mathbf{c}}{\mathbf{\lambda }}$.

Determine the wavelength of laser light 

The energy of a photon is, $E=\frac{hc}{\lambda }$.

Rearrange the above equation for $\lambda is\lambda =\frac{hc}{E}$.

Substitute $1240 \text{eV.nm}$ for hc and $2.25 \text{eV}$ for E in above equation.

$$\begin{gathered} \lambda =\frac{hc}{E} \\ =\frac{1240 \text{eV.nm}}{2.25 \text{eV}} \\ =551 \text{nm} \end{gathered}$$

Therefore, the wavelength of the light is 551nm.