Abstract: This article describes the construction of an experimental apparatus based on the Faraday effect and its non-reciprocal principle for omnidirectional detection of weak uniform and non-uniform magnetic fields. The system employs ZF6 heavy flint glass, a magneto-optical medium with intrinsic non-reciprocal properties. By implementing a multi-pass optical configuration to propagate the laser beam through the medium repeatedly, the magnetically induced rotation angle variations are amplified. Photodiodes integrated with transimpedance amplifiers convert these angular variations into quantifiable voltage signal modulations, magnetic field strength is obtained solely through voltage data acquisition utilizing either a voltmeter or an Arduino development board. Experimental results confirm that the device achieves high measurement accuracy, rapid response characteristics, low-cost implementation, and user-friendly operation.

Key words: weak magnetic field measurement, the Faraday effect, magneto-optical media, Photoelectric detection