Screen Based Apparatus for

Diffraction Experiments

Model: HO-ED-D-01

The apparatus Model No: HO-ED-D-01 is meant for studying diffraction when laser light passes through a diffracting element. The device consists of diode laser and diffracting element that can be conveniently fixed on carriages, which are mounted on the anodized aluminum rail. One carriage holds laser head and the other carriage holds a diffracting element like single slit, double slit, etc. which can be replaced as per requirement.

The laser mount is kinematic with two dimensional positioning freedoms. This helps to direct the laser beam to the required point on the diffracting element. All materials used for the construction of this apparatus are corrosion free. The diffraction pattern is projected on to a screen or wall for performing experiments. This elementary apparatus is simple, economical and is well suited for graduate level Physics courses.

A diffraction element can be thought of as an optical component that has tiny grooves cut into it. The grooves are cut so small that their dimensions approach the wavelength of light.

Experiment Examples

Diffraction of light by single slit

The diffraction equation (condition for minima) is,

Sin θm   =   m λ   /   d

Where d is the slit width, m is the order, λ is the wavelength of laser used and θm is the angle subtended within the central maximum and mth order minimum.

From this we can find out the slit width d as

d   =   m λ   /   Sin θm

Diffraction of light by double slit

The diffraction equation (condition for maxima) is,

Sin θm   =   m λ   /   d

Where d is the slit width, m is the order, λ is the wavelength of laser used and θm is the angle subtended within the central maximum and mth order minimum.

From this we can find out the slit width d as

d   =   m λ   /   Sin θm

Diffraction of light by single wire

The diffraction equation (condition for maxima) is,

Sin θm   =   m λ   /   d

Where d is the slit width, m is the order, λ is the wavelength of laser used and θm is the angle subtended within the central maximum and mth order minimum.

From this we can find out the slit width d as

d   =   m λ   /   Sin θm

Diffraction of light by cross wire

The diffraction equation (condition for maxima) is,

Sin θm   =   m λ   /   d

Where d is the slit width, m is the order, λ is the wavelength of laser used and θm is the angle subtended within the central maximum and mth order minimum.

From this we can find out the slit width d as

d   =   m λ   /   Sin θm

Diffraction of light by wire mesh

The diffraction equation (condition for maxima) is,

Sin θm   =   m λ   /   d

Where d is the slit width, m is the order, λ is the wavelength of laser used and θm is the angle subtended within the central maximum and mth order minimum.

From this we can find out the slit width d as

d   =   m λ   /   Sin θm

Diffraction of light by transmission grating

The diffraction equation (condition for maxima) is,

Sin θm   =   m λ   /   d

Where d is the slit width, m is the order, λ is the wavelength of laser used and θm is the angle subtended within the central maximum and mth order minimum.

From this we can find out the slit width d as

d   =   m λ   /   Sin θm

Diffraction of light by circular aperture (Pinhole)

Radius of the Airy’s disc,

x   =   ( 1.22 l λ )   /   a

where,

a = Diameter of the aperture (pinhole),

l = Distance between the pinhole and the Screen,

λ = Wavelength of light,

x = Radius of the Airy’s disc

Thus we can find the diameter of the aperture (pinhole) using the equation

a   =   ( 1.22 l λ )   /   x

Related Topics

Single slit

Double slit

Single wire

Cross wire

Wire mesh

Transmission grating

Circular aperture (pin hole)
Features

Modern and user Friendly design

Precision diffraction elements

Fine adjustments for laser mount

Sharp diffraction pattern

Simple and easy operation
Scope of Supply

Optical Rail

Model No: ED-D-01-OR
Length
:
500 mm
Material
:
Black anodized Aluminum alloy
Quantity
:
1 no.

Kinematic Laser Mount

Model No: ED-D-01-KLM
Material
:
Black anodized Aluminum alloy
:
Using 80 tpi lead screws
:
+/-4 degrees
Quantity
:
1 no.

Cell Mount

Model No: ED-D-01-CM
Material
:
Black anodized Aluminum alloy
Diameter
:
30 mm
Quantity
:
1 no.

Diffraction Cells

Model No: ED-D-01-DC
Single slit
:
50 & 100 micron
Double slit
:
100 & 200 micron
Transmission grating
:
30 lines / mm
Single wire
Cross wire
Wire mesh
Pinhole
Quantity
:
1 set.

White Screen

Model No: ED-D-01-WS
Material
:
Acrylic
Dimension
:
300 x 200 mm
Quantity
:
1 no.

Diode Laser with Power supply (Red)

Model No: ED-D-01-DLPR
Wave length
:
650 nm
Optical power
:
3 mW
Quantity
:
1 no.

Accessories

User Manual

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