Optical magnetron for high efficiency production of optical radiation

An optical magnetron, comprising:

• a cylindrical cathode having a radius rc;
• an annular-shaped anode having a radius ra and coaxially aligned with the cathode to define an anode-cathode space having a width wa=ra−rc;
• electrical contacts for applying a dc voltage between the anode and the cathode and establishing an electric field across the anode-cathode space;
• at least one magnet arranged to provide a dc magnetic field within the anode-cathode space generally normal to the electric field;
• and
• a plurality of resonant cavities each having an opening along a surface of the anode which defines the anode-cathode space, whereby electrons emitted from the cathode are influenced by the electric and magnetic fields to follow a path through the anode-cathode space and pass in close proximity to the openings of the resonant cavities to create a resonant field in the resonant cavities;
• wherein the resonant cavities are each designed to resonate at a frequency having a wavelength λ, and a circumference 2πra of the surface of the anode is substantially greater than λ.

An optical magnetron, comprising:

• an anode and a cathode separated by an anode-cathode space;
• electrical contacts for applying a dc voltage between the anode and the cathode and establishing an electric field across the anode-cathode space;
• at least one magnet arranged to provide a dc magnetic field within the anode-cathode space generally normal to the electric field;
• and
• a high-density array of N resonant cavities formed along a surface of the anode which defines the anode-cathode space, each of the N resonant cavities having an opening whereby electrons emitted from the cathode are influenced by the electric and magnetic fields to follow a path through the anode-cathode space and pass in close proximity to the openings of the resonant cavities to create a resonant field in the resonant cavities;
• wherein N is an integer greater than 1000.

A magnetron, comprising:

• an anode and a cathode separated by an anode-cathode space;
• electrical contacts for applying a dc voltage between the anode and the cathode and establishing an electric field across the anode-cathode space;
• at least one magnet arranged to provide a dc magnetic field within the anode-cathode space generally normal to the electric field;
• a plurality of resonant cavities each having an opening along a surface of the anode which defines the anode-cathode space, whereby electrons emitted from the cathode are influenced by the electric and magnetic fields to follow a path through the anode-cathode space and pass in close proximity to the openings of the resonant cavities to create a resonant field in the resonant cavities;
• a common resonator around an outer circumference of the anode to which at least some of the plurality of resonant cavities are coupled to induce pi-mode operation.

A magnetron, comprising:

• an anode and a cathode separated by an anode-cathode space;
• electrical contracts for applying a dc voltage between the anode and the cathode and establishing an electric field across the anode-cathode space;
• a pair of magnets arranged at opposite ends of the anode to provide a dc magnetic field within the anode-cathode space generally normal to the electric field;
• and
• a plurality of resonant cavities each having an opening along a surface of the anode which defines the anode-cathode space, whereby electrons emitted from the cathode are influenced by the electric and magnetic fields to follow a path through the anode-cathode space and pass in close proximity to the openings of the resonant cavities to create a resonant field in the resonant cavities;
• wherein the anode comprises at least an upper anode and a lower anode, the resonant cavities of the upper anode are each designed to resonate at a frequency having a first wavelength and the resonant cavities of the lower anode are each designed to resonate at a frequency having a second wavelength different from the first wavelength.