Technical data

Diffraction intensity due to pin holes and circular obstacles

Article no: P2230301

Principle

Pin hole diaphragms and circular obstacles are illuminated with laser light. The resulting intensity distributions due to diffraction are measured by means of a photo diode.

Tasks

The complete intensity distribution of the diffraction pattern of a pin hole diaphragm (D1 = 0.25 mm) is determined by means of a sliding photo diode. The diffraction peak intensities are compared with the theoretical values. The diameter of the pin hole diaphragm is determined from the diffraction angles of peaks and minima.
The positions and intensities of minima and peaks of a second pin hole diaphragm (D2 = 0.5 mm) are determined. The diffraction peak intensities are compared with the theoretical values. The diameter of the pin hole diaphragm is determined.
The positions of minima and peaks of the diffraction patterns of two complementary circular obstacles (D*1 = 0.25 mm and D*2 = 0.5 mm) are determined. Results are discussed in terms of Babinet's Theorem.

Learning objectives

Huyghens principle
Interference
Fraunhofer and Fresnel-diffraction
Fresnel's zone construction
Coherence
Laser
Airy disk
Airy ring
Poissonâ's spot
Babinet's theorem
Bessel functions
Resolution of optical instruments

Scope of delivery

Diode pumped solid state laser, green, 1 mW, 532 nm	08765-99	1
Digital array camera	35612-99	1
Adapter, BNC male/4 mm female pair	07542-26	1
Optical bench expert, l = 1500 mm	08281-00	1
Base for optical bench expert, adjustable	08284-00	2
Slide mount for optical bench expert, h = 30 mm	08286-01	3
Universal Holder, rotational	08040-02	1
Screen, metal, 300 x 300 mm	08062-00	1
Screen, with diffracting elements	08577-02	1
PHYWE Digital multimeter, 600V AC/DC, 10A AC/DC, 20 MΩ, 200 µF, 20 kHz, −20°C…760°C	07122-00	1
Connecting cable, 32 A, red, various lengths	07362-01	1
Connecting cable, 32 A, blue, various lengths	07362-04	1