Holmarc’s Zeeman Effect Apparatus, Model: HO-ED-S-04A is designed for the determination of e/m ratio, which requires knowledge in optics, mechanics, electromagnetism, modern physics and computer operations. Traditional Zeeman effect apparatus needs more skills in operation and measurement. With its new and integrated design, this device is easier to setup and operate so that students can lay focus in understanding the principles and theories involved.

A low-pressure mercury lamp is placed inside a variable current electro-magnet. Radiation passes through a narrow-band interference filter (or Dye based filter), centered around the desired wavelength and enters the Fabry-Perot etalon. This device consists of two reflective parallel plates which serve to transmit strong incoming radiation at different orders of wavelength. The apparatus has a built-in minimum separation D = 3.995 mm. Small tilting knobs allow careful adjustment of the plate.

The significant difference in our setup is in the imaging system used for viewing and recording the interference patterns. We use a USB 2.0 camera, it can be directly connected to the PC to monitor the fringe pattern and can save desired pictures. This makes the alignment of the optics much easier and eliminates the need for photographic processing. The Fabry-Perot etalon is the heart of the apparatus which allows us to detect small shifts in wavelengths of light emitted from the source. Basically, it is a pair of parallel highly reflective mirrors separated by a distance.