Study of laser noises corresponding to different feedback configurations for blue-light optical pickup heads

Based on the technology of real-time laser noise measurement which had been developed for the red-light DVD optical storage system before, this study investigates the laser noises corresponding to different feedback configurations by using the optical system of a blue-light HD-DVD optical pickup head (OPH) with the numerical aperture (NA) of 0.65 and the laser wavelength of 405 nm. It combines with a digital servo controller for dynamically measuring the blue laser noise while operated in an OPH. Experimental results show the variations of relative intensity noise (RIN) values corresponding to focusing errors, lens off-axis errors, disk rotation speeds, and laser emitting powers, respectively.