Patent ID: 6693426
Filing Date: 2004-02-17
Classification: G01N,Y10T

Abstract:
A method for spatially resolved spin resonance detection in a material sample, the method comprising:providing an excitation signal, having an excitation magnetic field with a selected excitation magnetic field direction in a sample, the excitation signal having at least one of a substantially static amplitude and a time varying amplitude with a selected frequency component fexc; providing an external magnetic field, having a magnetic field direction oriented substantially perpendicular to the excitation magnetic field direction and having selected magnetic field strength values at one or more locations, in a selected portion of the sample, where the external magnetic field has at least one of a substantially static field component and a time varying field component having a frequency that is substantially lower than said excitation frequency fexc; allowing the external magnetic field and the excitation field to interact with at least one spin for at least one atomic constituent in the selected portion of the sample, and to produce a spin resonance signal arising from the at least one spin; using an evanescent wave probe, located adjacent to the sample, to perform at least one of (i) excitation and (ii) sensing of the spin resonance for the at least one spin, where the spin resonance signal is drawn from a group of resonance signals consisting of electron spin resonance, ferromagnetic resonance and nuclear magnetic resonance; providing a sensing mechanism having a detection port to detect the spin resonance signal for the at least one spin; providing a signal cancellation mechanism that suppresses presence of the excitation signal at the frequency fexc at the detection port when the spin resonance signal is sensed; providing low noise amplification of the signal sensed after suppression of the presence of the excitation signal at the detection port; and detecting the amplified signal of the spin resonance as an output signal.