Browsing by Author "Schlesinger, T. E."

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Laser diode active height control system for data storage applications
(2006-01-01)
Fang, Jen-Yu
;
Herget, Philipp
;
Bain, James A.
;
Schlesinger, T. E.
;
光電工程學系
We describe and characterize an active height control system for near-field data storage applications using a commercial laser diode as a direct position sensor. The self-mixing interference signal was experimentally characterized and the effective spot size of the laser sensor was also measured. A control system utilizing interference in the laser as feedback signal was constructed to drive a conventional DVD pickup with the laser sensor mounted. The residual position error is +/- 9nm when the rotation speed of a glass disk was 1500rpm and the vertical runout was 16 mu m. The approach limit was estimated to be 25nm when the laser size is reduced to 100 mu m.
Laser diode feedback sensor characterization experiments for data storage applications
(2006)
Herget, Philipp
;
Fang, Jen-Yu
;
Bain, James A.
;
Schlesinger, T. E.
;
光電工程學系
An experiment used to measure the effective spot size of a laser diode distance sensor is described. Experimental results indicate that the effective spot size is approximately 1 mu m and is independent of distance.
Optical feedback height control system using laser diode sensor for near-field data storage applications
(2007-12-01)
Fang, Jen-Yu
;
Tien, Chung-Hao
;
Shieh, Han-Ping D.
;
Herget, Philipp
;
Bain, James A.
We demonstrated a laser diode position sensor for a near-field height control system. The feedback signal of the laser diode sensor that resulted from self-mixing interferometry was characterized and modeled by a simplified method. Due to the fine spatial resolution of the laser sensor, an active, height control system with nanoscale position precision was designed and realized under a spinning disk for near-field applications.