Optical resonators with orthogonally polarized modes

A method of increasing the volume utilization of the gain medium of a laser, comprising the steps of:

• providing a laser comprising a resonator with said gain medium;
• providing at least one polarizing element;
• providing at least one optical mode control element;
• and
• disposing said at least one polarizing element and said at least one mode control element within said resonator, such that said resonator supports simultaneously first and second sets of modes with orthogonal polarization, each of said sets of modes having at least one region of higher intensity and at least one region of lower intensity.

An optical resonator comprising:

• end reflectors;
• at least one polarizing element operative to direct radiation with orthogonal polarizations along first and second paths in said resonator;
• at least one optical mode control element such that there exist in the resonator simultaneously first and second sets of modes with orthogonal polarization;
• and
• at least one phase adjustment element disposed in at least one of said first and second paths, operative to adjust the mutual phase of said first and second sets of modes, such that said modes are summed coherently.

A method of intra-cavity coherent summation of two orthogonally polarized beams, comprising the steps of:

• providing at least one polarizing element operative to direct radiation with orthogonal polarizations along first and second paths in said cavity;
• providing at least one optical mode control element such that there exist in the resonator simultaneously first and second sets of modes with orthogonal polarization;
• disposing at least one phase adjustment element in at least one of said first and second paths;
• and
• adjusting the mutual phase of said first and second sets of modes, such that said modes are summed coherently.