Interference and lasers experimental work

Content type

User Generated

Uploaded By

NfvsVdony

Pages

Physics 110

Diffraction Gratings/Laser

Lab # ____ Name ____________________________________________________ Date _________

Lab Partner(S) ____________________________________________________________________

I. EQUIPMENT LIST

• https://ophysics.com/l5b.html

Online lab

II. BACKGROUND INFORMATION

The purpose of this exercise is to study the properties of diffraction gratings. A diffraction grating

consists of a large number of equally spaced slits or rulings on a flat surface. The purpose of a

grating is to break light up into its spectrum of colors. The basic grating equation is

   = d(x/L)

…where

is the wavelength of the light, d is the slit separation distance, m is an integer and is the

order of the spectrum, and θ is the angle to which the wavelength λ is diffracted by the grating.

When the angle is small (<10

) the equation can be approximated by d(x/L), where d is the same,

and x is the distance of the bright spot from the center line, and L is the distance from the diffraction

grating to the screen.

The online lab simulates a monochromatic light source passing through a diffraction grating and

shining on a screen. You can adjust various parameters of the experiment and view the

interference pattern that occurs.

III. EXPERIMENAL PROCEDURE

A. Open the link above and observe the set up.

B. Set the lens to grating distance to 5.0 m

C. Set the grating lines per mm to 200

D. Set the wavelength to 532 nm

E. Record the distance to the first two bright spots on either side of the central spot.

Repeat steps A -E for a wavelength of 650 nm

Repeat steps A –E for grating lines per mm of 400 (532 wavelength)

IV. CALCULATIONS

A. Calculate the position of the maximums using the diffraction equation.

B. Calculate the percentage error between your calculated value and the measured value

V. Questions

A. What general relations can be made about the diffraction grating and the patterns produced

B. Do you think there is anything that you could do that would decrease your percentage error?

Access over 35 million academic & study documents