Near-field semiconductor probe arrays with very high throughput efficiency had been developed
in this project. This was done by developing nano-fabrication processes with self-alignment technology
between the focal points of the micro-lens array fabricated on the probe substrate and the nano
apertures of the near-field optical probe array on the same substrates, which had been developed in
this project using special photo-resist layers that consist of an UV sensitive photo-resist and a special
IR sensitive emulsion. One of the reasons why the throughput efficiency of this array on the
semiconductor substrate is more than thousand times as high as compared to the conventional probes
is the success of fabrication processing for the micro-lens array on a single crystal semiconductor thin
wafer. The self-alignment technology in this project can cause the laser beam to focus within just
inside of the near-field semiconductor probe with the accuracy of 10 nano meter between optical axe
and center of the aperture. As there is no loss from the output windows to the flat top aperture tip of
the near-field optical probes, the conversion efficiency between the far-field light to the near-field light
which can be observed just outside of the aperture of the probes is depended on the far-field beam
waist size vs. evanescent wave aperture size. Finally we could get more than 10 % throughput
efficiency for the case of 100 nm aperture sizes. In the case of the near-field arrayed apertures located
periodically on the surface of the metal film or dielectric material mutual interaction between the
evanescent lights emitted from each aperture emphasis each other the evanescent light intensity. This
may be occurred by owing to the surface plasmon polariton effect. More appropriate aperture distance
and location distribution will make the enhancement stronger with the improvement of the
fabrication process for the aperture array. Beside the great improvement of the probe array for the
writing bits on the surface of the disk a novel signal detection method from the super high density
optical written disk surface was also improved by using the same VCSEL array optical head which has
both the micro-lenses and periodically positioned optical apertures. The VCSEL impedance between
the two electrodes of the each VCSEL element changes with the reflected feed back light from the disk.
This can be a very good new signal detection method in a higher density optical phase change disk.
The simulation of in both the probe array and the signal detection analysis were performed using
improved time domain finite differentiation (FDTD) method which had been published by us. Two
dimensional optical head will lead very high data transfer rate in the optical disk in near future.
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