Method and apparatus for producing a pulsed laser beam

A pulsed laser comprising:

• a resonator cavity having a resonator arm;
• a gain cavity having a gain arm;
• a pulse shortening element disposed in the resonator arm and excluded from the gain arm;
• and
• an optical switch for controllably selecting between the resonator arm and the gain arm.

An active-passive mode locked laser comprising:

• a first high reflectivity mirror;
• a second high reflectivity mirror, a first beam path being defined between the first high reflectivity mirror and the second high reflectivity mirror;
• a loss module disposed in the first beam path;
• an active mode locker disposed in the first beam path;
• a passive mode locker disposed in the first beam path;
• a third high reflectivity mirror, a second beam path being defined between the first high reflectivity mirror and the third high reflectivity mirror and having a common beam path segment in common with the first beam path;
• a cavity dumper disposed in the common beam path segment and having an output beam path;
• a gain module disposed in the common beam path segment;
• and
• a switch disposed in the common beam path segment at a first end thereof, a second end of the common beam path segment being at the first mirror.

A method for producing a high power pulsed laser beam comprising:

• establishing at least one light pulse in a first beam path;
• shortening the light pulse in the first beam path to obtain at least one short light pulse, the first beam path comprising a passive pulse shortening element;
• directing the short light pulse into a second beam path, the passive pulse shortening element being absent from the second beam path;
• and
• amplifying the short light pulse in the second beam path to obtain at least one high power short light pulse.

A method of operating a laser to produce a pulsed laser beam, comprising:

• establishing light in a resonator cavity of the laser to produce a first light pulse, the resonator cavity comprising a saturable absorber having a saturation level, and the first light pulse having a duration and further having a peak power below the saturation level of the saturable absorber;
• amplifying light in the resonator cavity to produce a second light pulse having a peak power above the saturation level of the saturable absorber and a duration less than the duration of the first light pulse;
• directing the second light pulse from the resonator cavity into a gain cavity, the gain cavity excluding the saturable absorber;
• amplifying the second light pulse in the gain cavity to obtain a third light pulse having a peak power above the peak power of the second light pulse;
• and
• outputting the third light pulse from the laser.