One of the most common materials used for Faraday rotation is terbium gallium garnet (TGG). Moreover, the Verdet constant is wavelength (and temperature) dependent, meaning that a different magnetic field strength and length will be required for different light sources. The Verdet constant is a material property, and is typically very low for most crystals - the discover of novel materials that enable Faraday rotation is an active area of research. Where \(V\) is the Verdet constant of the crystal, \(B\) is the magnitude of the magnetic field within the crystal (assumed to be constant), and \(L\) is the length of the crystal. wavelength plot for terbium gallium garnet Then, as light passes through the crystal, its polarization state is rotated by an angle: The optical crystal is oriented within the magnetic field, such that its optical axis is parallel to the direction of the magnetic field. The Faraday rotator is comprised of the magnetic field and the nonlinear optical crystal. Thus, the four main components of a Faraday isolator are: an input linear polarizer, a strong magnetic field, a nonlinear optical crystal, and an output linear polarizer. The following is a guide on how to fabricate a low-cost alternative to commercial Faraday isolators (typically >$1000 in cost).Ī Faraday isolator utilizes the Faraday effect and the polarization of light to allow the transmission of light in only one direction. For a discussion of the motivation behind Faraday isolators, please see the section on frequency-stabilized lasers.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |