Tools for laser spectroscopy: The design and construction of a Faraday isolator

We discuss the design and construction of a Faraday isolator for diode laser spectroscopy using commercially available components. The design involves modelling the magnetic field of an assembly of cylindrical magnets and verifying the predictions using a sensor. We obtain an isolation ratio for optical feedback of ∼35 dB at a wavelength of 780 nm. The cost is approximately one-fourth the cost of an equivalent commercially available device. We expect that the design can be widely used in experiments in laser spectroscopy and in advanced undergraduate laboratory experiments.PACS Nos.: 01.50.Pa, 32.80.Pj, 39.25.+k, 42.62.Fi