Classically, pulsed flashlamps have been driven (excited electrically) with a single loop RLC critically damped circuit. The capacitor is chosen for the required energy output, the inductor tunes the peak current for optical output requirements, and the resistor is used to ensure that the circuit is critically damped (that is no current reversal that can extinguish the lamp). A few circuits using several discharge loops, known as a pulse forming network, or PFN, have been explored but again, the current in the lamp is controlled by the passive circuit components. With both circuits, a two state closing switch,such as an SCR, is used to initiate current flow. This approach severally limits the agility in changing the drive characteristics as it is a "point design." To make such a change, the entire discharge circuit must be redesigned. The new excitation circuit utilizes the active region of high power field effect transistors in a Class A or Class AB amplifier circuit to provide a linear control of the flashlamp current. Having linear control will eliminate the need for simmer circuits required when a two state closing switch is used, (the simmer circuit keeps the flashlamp ionized in the interpulse period.) Also, since the optical output of the flashlamp is dependent on the lamp current, the spectral output can be adjusted to enhance wanted frequencies and depress unwanted wavelengths which will lead to greater efficiency which is not the case in a single point design circuit.