Abstract: A high average power free electron laser (HAPFEL) architecture supporting multiple gain generator configurations with multiple synchronized output beams. The HAPFEL generates straight-line counter-propagating electron beams. Multiple RF electron guns and Superconducting Dual-axis Energy Recovery Linacs (SDERLs) define a fixed physical configuration for generating the counter-propagating electron beams and for recovering electron beam energy. A gain generator may be reconfigured into different configurations without physically reconfiguring the hardware supporting the counter-propagating electron beams.

Abstract: Helper resonators useful for the reliable, controlled startup of an associated high power multidisk unstable imaging thin disk laser (TDL) main resonator each includes one of the thin disk gain elements (TDGEs) of the associated main resonator and a pair of helper reflectors disposed on opposite sides thereof. The helper resonators act to prevent the buildup of undesirable amplified spontaneous emission (ASE) during startup of the main resonator, pre-condition the TDGEs so as to enable efficient power transfer from the helper resonators to the main resonator when the main resonator reaches a selected feedback ratio (FBR) and provide a rapidly acting shunt for disk power in the event of a cessation of lasing of the main resonator.

Abstract: A computer may include a database and a power reducing routine. The database may be configured to store an input power level of an input laser beam transmitted onto and storing power within a gain module. The database may be further configured to store a discharge power level of at least partially discharged stored power discharged from the gain module through an output laser beam. The database may also be configured to store a power safety differential limit. The power reducing routine may include an algorithm. The algorithm may be configured to calculate a power differential by subtracting the discharge power level from the input power level, and to at least one of reduce power to and shut down the input laser beam if the calculated power differential exceeds the power safety differential limit.

Abstract: Helper resonators useful for the reliable, controlled startup of an associated high power multidisk unstable imaging thin disk laser (TDL) main resonator each includes one of the thin disk gain elements (TDGEs) of the associated main resonator and a pair of helper reflectors disposed on opposite sides thereof. The helper resonators act to prevent the buildup of undesirable amplified spontaneous emission (ASE) during startup of the main resonator, pre-condition the TDGEs so as to enable efficient power transfer from the helper resonators to the main resonator when the main resonator reaches a selected feedback ratio (FBR) and provide a rapidly acting shunt for disk power in the event of a cessation of lasing of the main resonator.

Abstract: A computer may include a database and a power reducing routine. The database may be configured to store an input power level of an input laser beam transmitted onto and storing power within a gain module. The database may be further configured to store a discharge power level of at least partially discharged stored power discharged from the gain module through an output laser beam. The database may also be configured to store a power safety differential limit. The power reducing routine may include an algorithm. The algorithm may be configured to calculate a power differential by subtracting the discharge power level from the input power level, and to at least one of reduce power to and shut down the input laser beam if the calculated power differential exceeds the power safety differential limit.

Abstract: A system and method for detecting thrust in a remote object is disclosed herein. The system is suitable for use in connection with midcourse discrimination systems that distinguish actual targets of interest, such as warheads, from decoys. The system directs laser pulses at the remote object under observation. The system directs at least one initial laser pulse at the remote object to heat the surface material of the remote object and to create an outgas environment near the remote object. The system also directs at least one secondary laser pulse at the outgas environment, which creates very high peak power filaments that bombard the surface of the remote object. The filaments ablate the surface material of the remote object, ejecting mass away from the remote object at a high velocity. The ejection of mass imparts thrust to the remote object, resulting in an imparted differential velocity dependent on the mass of the remote object.