A method to enable a laser to interact with a structure behind a barrier includes calculating a set of characteristics for a first laser channel to be effective to tunnel through the barrier and calculating a second set of characteristics for a second laser channel to be effective to interact with the structure, generating said first laser pulse to form a tunnel through the barrier and prior to closing of the tunnel, generating the second laser pulse to travel through the tunnel to interact with the structure. A treatment unit associated with this method has a control panel in communication with an electronics package. Data entered into the control panel enables the electronics package to calculate the first and second sets of characteristics and drive a first laser generating a laser pulse of the first laser channel followed after a delay by a laser pulse of the second laser channel.
