Translator Disclaimer
30 November 1999 VERSATEST-I: a versatile polychromatic dynamic testbed for optical disks
Author Affiliations +
A polychromatic versatile dynamic testbed for the evaluation of optical disks is presented. The system can be used for all wavelengths from 400 to 690(780) nm, allowing any laser source in this range -- especially the new blue laser diodes -- to be utilized for read-write-erase experiments. In addition, the system allows testing of disk with substrate thicknesses ranging from 0 to 1.7 mm. The polarization of the system can easily be changed from linear to circular at the disk surface, so the use of both magneto-optical (MO) and phase-change disks (PD) is possible, in addition to read-only disks (CD, DVD). A variable leaky polarizing beam splitter has been specially designed for this tester. This device allows to continuously adjust the ratio between the s- an p- polarized components for the reflected beam reaching the detectors, enabling the optimization of the signal-to-noise ratio while adjusting the relative amounts of the two components of polarization at the detectors. The astigmatic method is used for focus control and the push-pull method is used for track control (other focusing and tracking schemes like DPD are under preparation). In an optional setup, the RF data signal and the focus and track servo signals can be derived from the same high speed quad detectors, allowing the use of the full optical power returning of the disk for all these purposes. So the astigmatic FES, the push-pull TES, the differential magneto- optical readout signal and the conventional sum signal for phase-change readout as well as the differential edge-signal for mark-edge detection are obtained. In this paper, we are presenting the basic functions of VERSATEST-I as well as future enhancements for latest optical data storage technology. Additionally typical test results on magneto- optical disks and phase-change disks (DVD-RAM 5.2GB) are reported.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Bernhard J. Wolfring, Thomas Weber, Thomas Mueller-Wirts, and Masud Mansuripur "VERSATEST-I: a versatile polychromatic dynamic testbed for optical disks", Proc. SPIE 3806, Recent Advances in Metrology, Characterization, and Standards for Optical Digital Data Disks, (30 November 1999);


Tracking Servo For Small Size Optical Disk System.
Proceedings of SPIE (January 14 1987)
Interlinked Tracking Servo Technology
Proceedings of SPIE (January 14 1987)
Land/groove recording in MO systems
Proceedings of SPIE (September 08 1995)
Autofocus module for multilaser print heads
Proceedings of SPIE (December 08 1998)

Back to Top