a path across the substrate for material deposition according to this invention the dimensional accuracy of components fabricated using closed loop direct metal deposition is improved through a nozzle design incorporating a rapid response semiconductor laser this improvement in conjunction with improved powder focusing characteristics powder utilization and shielding achieves enhanced surface finish characteristics in this invention a diode laser is used as the energy source for the closed loop dmd system the optical signal from the laser interaction zone is used to modulate the diode laser to control the power since the diode lasers can respond to signals at a rate up to 20 khz the laser power can be finely tuned to the process at faster rate than that by co 2 or yag lasers and thus the deposition height 0025 fig3 is a flow chart for the optical feedback control loop for the diode laser based dmd system at block 301 an optical signal is obtained from the deposition zone at block 304 logic circuitry is used to modulate the laser power with a signal being sent to the diode laser power supply at a frequency to 0 to 20 khz or higher frequency depending upon the response time of the device this is delivered to the laser deposition zone at 308 in the form of optical energy but the question regarding height or other physical characteristics being asked at decision block 310 if the height or other characteristics is acceptable the process continues at 312 otherwise control is returned to block 302 for the receipt of a new optical signal a primary advantage of diode laser.