# Diffraction Gratings, confusing question.

• skg94
In summary, the conversation discusses the equations and variables involved in solving a problem related to diffraction grating. The variables include d for the distance between lines at the grating, n for the order of the line, x for the distance from the central to the node, and l for the length of the ruler. The conversation also clarifies that the lines on the ruler are arbitrary and that the calculations should be done with units.
skg94

λ=xd/nl

## The Attempt at a Solution

Im having some difficulty with the variables, is d= lines/m? and n= 27? from the 50 mark to the yellow mark. then x would be 27*(4.35*10^-6) and l would be 100cm=1m ?

d is the distance between lines at the grating.
n is the order of the line. As you have just one line for each color (0 would correspond to light directed towards the tube), it is 1.

then x would be 27*(4.35*10^-6)
That looks like xd, but it has no units and where does the value of 27 come from?

and l would be 100cm=1m ?
Right

27 lines from thr 50 to yellow

Those are lines on the ruler, they are completely arbitrary (you could use a ruler with mm-marks as well). 13.5cm is the physical quantity, it does not depend on the type of ruler.

i just assumed that because of the each etched mark is 4.35*10^-6 apart, so d would be 4.35*10^-6 but x would be that times the 27 lines from the distance from central to the node.

So x =.135m d= 4.35*10^-6 l =1 and n= 1 so really the calculation is (.135*4.35*10^-6) ?

With units, yes.

Those lines ~4µm apart are at the diffraction grating, not at the ruler.

## 1. What is a diffraction grating?

A diffraction grating is an optical component with a series of parallel grooves or lines that are evenly spaced. When light passes through the grating, it is diffracted into multiple beams, creating a spectrum of colors.

## 2. How does a diffraction grating work?

A diffraction grating works by causing interference between the diffracted light waves, resulting in a pattern of bright and dark fringes. The spacing of the grooves on the grating determines the angle at which the light is diffracted, and therefore, the resulting spectrum.

## 3. What is the difference between a transmission and reflection diffraction grating?

A transmission diffraction grating allows light to pass through the grooves and is commonly used for spectroscopy. A reflection diffraction grating reflects light off the surface of the grooves and is often used in optical instruments such as telescopes.

## 4. How do you calculate the grating spacing?

The grating spacing, also known as the grating constant, can be calculated by dividing the wavelength of light by the number of grooves per unit distance on the grating surface. This value is typically given in units of lines per millimeter (l/mm) or lines per inch (lpi).

## 5. What are some applications of diffraction gratings?

Diffraction gratings have many applications, including spectroscopy, wavelength measurement, and optical communication. They are also used in the production of holograms, optical filters, and laser systems.

Replies
3
Views
2K
Replies
6
Views
470
Replies
8
Views
25K
Replies
10
Views
2K
Replies
5
Views
2K
Replies
6
Views
4K
Replies
1
Views
3K
Replies
5
Views
5K
Replies
3
Views
1K
Replies
3
Views
5K