Optical magnetron for high efficiency production of optical radiation, and 1/2λ induced pi-mode operation

A magnetron, comprising:

• an anode and a cathode separated by an anode-cathode space;
• electrical contacts for applying a voltage between the anode and the cathode for establishing an electric field across the anode-cathode space;
• and
• at least one magnet arranged to provide a magnetic field within the anode-cathode space generally normal to the electric field,
• wherein the anode comprises a plurality of washer-shaped layers stacked atop each other to form a hollow-shaped cylinder having the anode-cathode space located therein, and each of the plurality of layers includes a plurality of recesses along an inner diameter which are aligned with recesses of the others of the plurality of layers to define a plurality of resonant cavities along an axis of the cylinder each having an opening to the anode-cathode space.

A magnetron, comprising:

• an anode and a cathode separated by an anode-cathode space;
• electrical contacts for applying a 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 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;
• and
• a common resonator around an outer circumference of the anode to which at least some of the plurality of resonant cavities are coupled via coupling ports to induce pi-mode operation,
• wherein at least some of the coupling ports introduce an additional ½λ delay relative to others of the coupling ports, where λ is an operating wavelength of the magnetron.