Title :
Measurement of head/disk spacing with a laser interferometer
Author :
Zhu, L.Y. ; Hallamasek, K.F. ; Bogy, D.B.
Author_Institution :
Dept. of Mech. Eng., California Univ., Berkeley, CA, USA
fDate :
11/1/1988 12:00:00 AM
Abstract :
A multichannel heterodyne laser interferometer was built to measure the head-disk spacing in magnetic disk drives. The main advantage of the present method compared to white light interferometry and capacitive measurements is that neither the disk nor the slider need be transparent or conductive. The interferometer is described, including the optics and electronics. Experimental results on head-disk spacing during the take-off, flying and landing processes are presented and discussed. It is concluded that the present system is capable of making the desired measurement with minimum modification of the slider. It has a resolution of 2.5 nm and a bandwidth of DC to about 40 kHz
Keywords :
distance measurement; light interferometers; light interferometry; magnetic disc storage; magnetic heads; measurement by laser beam; 0 to 40 kHz; 2.5 nm; head/disk spacing; laser interferometer; magnetic disk drives; multichannel heterodyne type; resolution; Disk drives; Laser beams; Magnetic separation; Mirrors; Optical fiber polarization; Optical interferometry; Optical modulation; Optical retarders; Probes; Surface emitting lasers;
Journal_Title :
Magnetics, IEEE Transactions on
