Title :
Diffraction Grating With Dual Modes for Two-Wavelength Rewritable Optical Pickup Heads
Author :
Shih, Hsi-Fu ; Li, Bo-Wei
Author_Institution :
Dept. of Mech. Eng., Nat. Chung-Hsing Univ., Taichung
Abstract :
This paper discloses the configuration of a dual-mode three-beam grating which adopts the liquid-crystal (LC) modulator technologies and has the function of switching diffraction properties. With the specific design of the top, bottom, and complementary electrodes, the grating has the feature of being modulated by external electric field for generating two diffraction modes. Two modes corresponding to different diffraction directions and angles were verified by experiments. This device could be applied to the fabrication of a monolithic three-beam grating, which is necessary for the tracking detection of a rewritable two-wavelength optical head using a two-wavelength integrated laser diode (TWIN-LD)
Keywords :
diffraction gratings; digital versatile discs; light diffraction; liquid crystal devices; optical modulation; pick-ups; semiconductor lasers; CD; DVD; diffraction grating; dual-mode three-beam grating; external electric field; liquid-crystal modulator; monolithic three-beam grating; switching diffraction properties; tracking detection; two-wavelength integrated laser diode; two-wavelength rewritable optical pickup heads; DVD; Diffraction gratings; Diode lasers; Electrodes; Integrated optics; Laser beams; Optical crosstalk; Optical diffraction; Optical modulation; Optical surface waves; Diffractive optical element (DOE); liquid crystal (LC); optical pickup head; three-beam grating; two-wavelength integrated laser diode (TWIN-LD);
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2006.888499
