STI is developing fiber optic pulsed polarimetry (FOPP) as a new type of magnetic field diagnostic. Laser light is sent through a single-mode optical fiber, which when exposed to a magnetic field causes the polarization of the laser light inside the fiber to rotate. Detecting the light backscattered from the fiber and measuring the polarization rotation can be used to determine the magnetic field strength at any position along the fiber. Moreover, by utilizing a laser that emits pulses of light at a very high repetition rate (e.g., 1 million times per second), the scientist can identify changes in the magnetic field with fine time resolution.
This new type of diagnostic may be particularly useful for magnetic fusion devices like tokamaks, which rely on powerful magnetic fields to confine the extremely hot plasma inside the device. Compared to existing magnetic field diagnostics, FOPP can provide much more detailed measurements of the magnetic field both in space and time.
STI is also performing research to identify how FOPP can benefit high-temperature superconducting magnetic devices.
For more information on our FOPP diagnostic, please contact us.