Pulse Stretching Technique for Laser Bond Inspection, Laser Ultrasonic Inspection, and Laser Peening

An inspection system comprising:

• a laser system comprising:
• a laser configured to provide laser pulses,
• a plurality of pulse stretchers coupled together in series, the plurality of pulse stretchers configured to stretch pulse widths of the laser pulses and output stretched laser pulses,
• a feedback module configured to adjust a parameter of at least one pulse stretcher of the plurality of pulse stretchers based on a comparison of a first laser pulse of the laser pulses and a corresponding first stretched laser pulse of the stretched laser pulses, and
• a lens assembly configured to direct a second stretched laser pulse of the stretched laser pulses to a workpiece after the feedback module adjusts the parameter of the at least one pulse stretcher;
• and
• a detector configured to detect a response of the workpiece to the second stretched laser pulse.

A method for inspecting a workpiece bondline comprising:

• stretching a pulse width of a first laser pulse using a plurality of pulse stretchers coupled in series so as to obtain a first stretched laser pulse;
• comparing the first laser pulse and the first stretched laser pulse;
• adjusting a parameter of at least one pulse stretcher of the plurality of pulse stretchers based on a result of the comparing of the first laser pulse and the first stretched laser pulse;
• after adjusting the parameter, stretching a pulse width of a second laser pulse using the plurality of pulse stretchers so as to obtain a second stretched laser pulse;
• delivering the second stretched laser pulse to the workpiece bondline;
• and
• detecting a response of the workpiece bondline to the second stretched laser pulse.