Question

The most widely used laser is He-Ne laser with a wavelength of 632.8nm.What is its speed and frequency?

Answer 1

Since it is a laser we can assume that the speed is equal to the speed of light, therefore, its speed is given by:

`v=c=3*10^8m/s`

Now, using the following equation:

`\begin{gathered} v=\lambda f \\ so: \\ f=(v)/(\lambda) \\ where: \\ v=3*10^8m/s \\ \lambda=632.8*10^(-9)m \\ so: \\ f=(3*10^8m/s)/(632.8*10^(-9)m) \\ f\approx4.74*10^(14)Hz \end{gathered}`

Answer:

4.74x10¹⁴ Hz