# The laser used in cornea

• Aug 16th 2006, 06:15 PM
tacubo
The laser used in cornea
The laser used in cornea surgery to treat corneal disease is the excimer laser, which emits ultraviolet light with a wavelength of 193 nm in air. The index of refraction of the cornea is 1.376. What are the wavelength and frequency of the light in the cornea?
• Aug 16th 2006, 08:25 PM
CaptainBlack
Quote:

Originally Posted by tacubo
The laser used in cornea surgery to treat corneal disease is the excimer laser, which emits ultraviolet light with a wavelength of 193 nm in air. The index of refraction of the cornea is 1.376. What are the wavelength and frequency of the light in the cornea?

The frequency is the same in both media, then as:

$\lambda=\frac{c}{f}$

the wavelength is proportional to the speed of light, and the refractive index
$n$ is the ratio of the seed of light in vacuum to that in the medium, so we have:

$\frac{\lambda_1}{\lambda_0}=\frac{c_0}{c_1}=n$.

where $\lambda_0$ is the wavelength in vacuum (virtually the
same as in air). So:

$\lambda_1=n \lambda_0$,

and as you are told $n$, and $\lambda_0$, you can complete the answer.

RonL