Klinger Scientific Single Slit Experiment Set Up

In a single slit experiment, an alternating dark and bright pattern can be seen when light is imposed on a slit with a size corresponding to the wavelength of light. The only differences between a single slit and a double-slit experiment are the diffraction patterns and the intensity graphs.

Objectives:
• To find wavelength of given laser using the slit of known width.
• To find the slit width knowing the wavelength of light used.
• Proving the concept of Heisenberg uncertainty principle.

Principle:
Diffraction is a phenomenon of bending of waves when it encounters obstacles or narrow opening. A basic set up to observe diffraction consists a
laser, a slit, screen placed at a distance. The wave fronts are partially obstructed by the slit. The intensity distribution of the diffraction pattern consists of a series of light and dark fringes with the intensity distribution is symmetric along about the central axis. The primary peak is called the central maxima. The corresponding peaks are called secondary, tertiary maxima. This is studied using the single slit experiment.

Key Features:
• Precise Optical Alignment: The optical alignment of the components is attained by optical bench, the setting up time is faster and experimentation is easy.
• Digital Lux Meter with Transverse Saddle: The digital Lux meter enables measurement of light intensity. The transverse saddle helps in fine movement of Lux meter perpendicular to the direction of light.

Components of set up:

Light passing through a single slit forms a diffraction pattern somewhat different from those formed by double slits or diffraction gratings. Figure 1 shows a single slit diffraction pattern. Note that the central maximum is larger than those on either side, and that the intensity decreases rapidly on either side. In contrast, a diffraction grating produces evenly spaced lines that dim slowly on either side of center.

The analysis of single slit diffraction is illustrated in Figure 2. Here we consider light coming from different parts of the same slit. According to Huygens’s principle, every part of the wavefront in the slit emits wavelets. These are like rays that start out in phase and head in all directions. (Each ray is perpendicular to the wavefront of a wavelet.) Assuming the screen is very far away compared with the size of the slit, rays heading toward a common destination are nearly parallel. When they travel straight ahead, as in Figure 2a, they remain in phase, and a central maximum is obtained. However, when rays travel at an angle θ relative to the original direction of the beam, each travels a different distance to a common location, and they can arrive in or out of phase. In Figure 2b, the ray from the bottom travels a distance of one wavelength λ farther than the ray from the top. Thus a ray from the center travels a distance λ/2 farther than the one on the left, arrives out of phase, and interferes destructively. A ray from slightly above the center and one from slightly above the bottom will also cancel one another. In fact, each ray from the slit will have another to interfere destructively, and a minimum in intensity will occur at this angle. There will be another minimum at the same angle to the right of the incident direction of the light.

INSTRUCTIONS FOR USE CLICK HERE