1. With the later on given info, is it possible to through geometry calculate the wave length of a HeNe Laser?(adsbygoogle = window.adsbygoogle || []).push({});

2. Relevant equations and facts

A Helium Neon laser emitts light through a double slit and towards a screen where a central image and the first dimmer bands can be seen.

The distance from the the HeNe laser to the screen is 757 cm, and the distance between the central band and the dimmer bands are 6 cm.

The frequency and the width of the double slit are both unknown factors.

3. The attempt at a solution

With the Pythagorean theorem the distance between the double slit and the screen can be calucaled, and with "simple geometry" the directional angle can be calculated.

I am thinking that the if one calculates the difference of

1. the distance between the double slit and the central band

and

2. the distance between the double slit and the nearest dimmer band

the answer could also be the wave length of the laser?

However, the answer of the calculation which is 757 minus the squareroot of (757^2+6^2) = 0,023777 cm. And since the HeNe lasers has a wave length somewhere around 630 nm I am suspecting my theory is off.

Most grateful for any shared thoughts on this,

Pete

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Problem and thoughts about simple light interference

**Physics Forums | Science Articles, Homework Help, Discussion**