Optical memory

Integrated optics technologies are expected to play an important role in the development of new devices for future optical memory systems. We have been leading this subarea since we proposed and demonstrated an integrated-optic disc pickup device (IODPU) in 1985. The devices studied include the prototype IODPU and a number of its modifications, IO magnetooptic disc pickup devices, IO parallel data pickup devices for optical card, all implemented by integration of grating components and photodiodes in glass on Si waveguides. The proposed devices are fabricated and tested to demonstrate the unique performances and the advantages. Theoretical analysis and simulation on readout characteristics with the super-resolution capabilities are performed. Recent work includes monolithic integration of grating components and quantum-well DFB laser diode in GaAs waveguide for implementation of subminiature fully-integrated disc pickup head. Application of electrooptic polymer waveguide is also studied for memory device application such as focus intensity modulator.

Fig.3 The prototype integrated-optic disc pickup device (IODPU).

Fig.4 Monolithic integrated-optic disc pickup head using quantum-well DFB laser.

Fig.5 Simulated eye patterns of the super-resolution readout by integrated-optic disc pickup device.