Abstract: An imaging probe for imaging inside a cavity surrounded by a wall, the probe comprising: a) a probe body having a contracted state and an expanded state; and b) at least two imaging sensors, mounted on the probe body and having fields of view in different directions; wherein, when the probe body is in the expanded state, the fields of view of the imaging sensors respectively comprise portions of the wall of the cavity on different sides of the cavity.

Abstract: ESR microscope systems and methods for examining specimens using both continuous wave and pulsed modes in the 9 to 60 GHz range. The ESR microscope uses an image probe comprising gradient coils in addition to conventional modulation coils (in continuous wave mode) or magnetic field bias coils (in pulse mode), and a resonator constructed from high permittivity material. The systems and methods also involves the use of sample containers that permit the precise placement of samples in relation to the image probe. The microscope uses a microstrip or thin coaxial or dielectric antenna to obtain a high coupling coefficient to the specimen being imaged. The microscope systems provide resolution at the single micron level, and permit the observation of images comprising tens to hundreds of pixels for each of two or three dimensions in a few minutes. Novel stable radicals used as the imaging media are also described.

Abstract: An imaging probe and method and an MRI system utilizing the same are presented. The probe comprises first and second magnetic field sources, and a receiver of NMR signals. The first magnetic field source creates a primary, substantially non-homogeneous, static magnetic field in a region of interest in a medium outside the probe. The second magnetic field source creates an external time-varying magnetic field, which when being applied to the region of the static magnetic field, is capable of exciting nuclei in an extended sub-region of this region and generating the NMR signals.

Abstract: Optically pumped masers are described. The devices are useful for microwave amplification, microwave phase shifting and microwave limiting function. The devices are based on electron spin polarization of a stable free radical species induced by an intermolecular energy transfer process acting via a photo induced radical-triplet pair mechanism. A paramagnetic triplet precursor chromophore in a matrix with the stable free radical species is irradiated, preferably using a pulsed laser to initiate the process with concomitant increase in matrix magnetic susceptibility. Microwave radiation incident on the photo activated matrix is reflected as amplified, phase shifted or limited microwave fields dependent on relevant device parameters and on the power of the incident microwave radiation.

Abstract: An MRI system is presented utilizing a magnetic assembly of a kind which, when accommodated within a primary static reasonably homogeneous magnetic field created by the MRI system affects the static magnetic field to cause creation of a region of substantial non-homogeneity of the static magnetic field in the vicinity of the magnetic assembly. By this, a local static field gradient is created. The magnetic assembly comprises a passive magnetic element, which deforms a pattern of the static magnetic field, while not being a magnetic field source by to itself.