US Patent 7352784 Laser burst boosting method and apparatus

Methods and apparatus for managing thermal loads on a laser gain medium and for boosting the output power of a diode pumped laser are disclosed. The short-term average pumping power to the gain medium is increased, to provide a burst of pumping energy to the laser gain medium. A subsequent short-term reduction in the average pumping power then allows the gain medium to cool to a desired state steady level. The average pumping power is then increased to maintain this steady state level until the next burst is desired. For example, a pulse of current may be applied to a laser diode at a first current level I1 for a first time interval Δt1, where I1 exceeds a nominal current value Inom by an amount ΔI1. The current to the laser diode is reduced to a second current level I2 for a second time interval Δt2, where Inom exceeds I2 by an amount ΔI2. To balance the thermal load on the diode an integral of ΔI1 over the time Δt1 is approximately equal in magnitude to an integral of ΔI2 over the time Δt2. After applying the pulse of current at the first current level I1, and before or after reducing the current to the second level I2, the nominal current is applied to the laser diode for a third time interval Δt3.