Unique magneto-optical (Raman and Photoluminescence) measurement capabilities are established at NIST and under continual advancement. An automated magneto-cryostat1 is coupled with a triple-grating Raman spectrometer to enabled superior laser rejection, permitting excitations to be observed as low as 8 cm-1 or 1 meV or 0.3 THz. These apparatuses are also combined with multiple excitation lasers spanning wavelengths from 380 nm to 900 nm to enable resonant Raman scattering to be collected. Full control of the polarization of both the incoming laser light and the scattered light is a key capability to enable symmetry analysis of all modes observed. Present developments include electrical feedthroughs for simultaneous in-operando device transport and optical characterization, and full spatial mapping capabilities.
Samples can be probed in this “cryo” position (backscattering with an objective at cryogenic temperatures), but also in a “macro” position (e.g., liquid samples), or in the “micro” position (backscattering with multiple objectives, ambient conditions).
1Temperature (1.65 K to 400 K), Magnetic Field (0 to 9 T), both Faraday and Voigt geometries