Beam combining of diode laser array elements for high brightness and power

A method of generating optical radiation using an external cavity laser source, the method comprising:

• b) generating at least two free space optical beams with at least two optical gain elements, the at least two optical beams having at least a first and a second wavelength, respectively;
• c) propagating the at least two optical beams to an optical element that intercepts the at least two optical beams, the optical element being positioned so that the at least two optical gain elements are positioned substantially at a focal plane of the optical element;
• d) propagating the at least two optical beams to a dispersive element positioned so that their footprints are substantially overlapping;
• e) propagating the at least two optical beams to a partially reflecting element positioned to receive radiation from the dispersive element, the partially reflecting element and the gain element together forming a free space laser cavity that produces the at least first and second wavelengths;
• and
• f) transmitting an overlapping beam comprising radiation having the at least first and second wavelength through the partially reflecting element.

A method of improving beam quality and increasing the brightness of an external cavity laser source, the method comprising:

• g) generating at least two free space optical beams with at least two optical gain elements, the at least two optical beams having at least a first and a second wavelength, respectively;
• h) propagating the at least two optical beams to an optical element that intercepts the at least two optical beams, the optical element being positioned so that the at least two optical gain elements are positioned substantially at a focal plane of the optical element;
• i) propagating the at least two optical beams to a dispersive element positioned so that their footprints are substantially overlapping;
• j) propagating the at least two optical beams to a partially reflecting element positioned to receive radiation from the dispersive element, the partially reflecting element and the gain element together forming a free space laser cavity that produces the at least first and second wavelengths;
• k) transmitting an overlapping beam through a spatial filter that is positioned between the dispersive element and the partially reflecting element, thereby improving beam quality and increasing the brightness of the overlapping beam;
• and
• l) transmitting the overlapping beam comprising radiation having the at least first and second wavelengths through the partially reflecting element.