Versatile polychromatic dynamic testbed for testing of optical disks

A dynamic testbed has been designed and constructed for the evaluation of optical disks. Within the wavelength range of 440 nm to 690 nm, the system is achromatic, allowing any light source in this range to be utilized for read/write/erase experiments. The system also accepts disks with substrate thickness ranging from 0 to 1.7 mm. The testbed handles polarization such that with a turn of a knob, one can generate either linearly-polarized or circularly-polarized light at the disk surface. Focus error detection is based on the astigmatic method, and the primary track error detection scheme is the push pull method. The detection channel consists of two high-speed quad detectors mounted on the two arms of a differential detection module.