1. A method for laser voltage testing of active devices within a device under test (DUT), comprising: illuminating a selected area of the DUT with laser beam while the DUT is receiving test signals causing certain of the active devices to switch states; collecting reflected light from the selected area; converting the reflected light into an electrical signal; sampling the electrical signal using an analog to digital (ADC) converter and thereby providing digital output; applying the digital output to a field programmable gate array (FPGA) and using the FPGA to perform operations on the digital output and thereby generate laser voltage testing signal corresponding to the switching states of the active devices within the selected area.