13-08-2012, 01:15 PM
Optical Computing Technology
Optical Computing.pdf (Size: 224.11 KB / Downloads: 63)
Introduction
With today’s growing dependence on computing technology,
the need for high performance computers (HPC) has significantly
increased. Many performance improvements in conventional
computers are achieved by miniaturizing electronic components
to very small micron-size scale so that electrons need to
travel only short distances within a very short time. This approach
relies on the steadily shrinking trace size on microchips
(i.e., the size of elements that can be ‘drawn’ onto each chip).
This has resulted in the development of Very Large Scale
Integration (VLSI) technology with smaller device dimensions
and greater complexity. The smallest dimensions of VLSI nowadays
are about 0.08 mm. Despite the incredible progress in the
development and refinement of the basic technologies over the
past decade, there is growing concern that these technologies
may not be capable of solving the computing problems of even
the current millennium.
Background
Optical computing was a hot research area in the 1980s. But the
work tapered off because of materials limitations that seemed to
prevent optochips from getting small enough and cheap enough
to be more than laboratory curiosities. Now, optical computers
are back with advances in self-assembled conducting organic
polymers that promise super-tiny all-optical chips [1]. Advances
in optical storage device have generated the promise of
efficient, compact and large-scale storage devices [2]. Another
advantage of optical methods over electronic ones for computing
is that parallel data processing can frequently be done much
more easily and less expensively in optics than in electronics [3].
Some Key Optical Components for Computing
The major breakthroughs on optical computing have been centered
on the development of micro-optic devices for data input.
Conventional lasers are known as ‘edge emitters’ because their
laser light comes out from the edges. Also, their laser cavities
run horizontally along their length. A vertical cavity surface
emitting laser (VCSEL – pronounced ‘vixel’), however, gives
out laser light from its surface and has a laser cavity that is
vertical; hence the name. VCSEL is a semiconductor vertical
cavity surface emitting microlaser diode that emits light in a
cylindrical beam vertically from the surface of a fabricated
wafer, and offers significant advantages when compared to the
edge-emitting lasers currently used in the majority of fiber optic
communications devices. They emit at 850 nm and have rather
low thresholds (typically a few mA).
Uses of Optics in Computing
Currently, optics is used mostly to link portions of computers,
or more intrinsically in devices that have some optical application
or component. For example, much progress has been
achieved, and optical signal processors have been successfully
used, for applications such as synthetic aperture radars, optical
pattern recognition, optical image processing, fingerprint enhancement,
and optical spectrum analyzers. The early work in optical
signal processing and computing was basically analog in nature.
In the past two decades, however, a great deal of effort has
been expended in the development of digital optical processors.
Optical Computing.pdf (Size: 224.11 KB / Downloads: 63)
Introduction
With today’s growing dependence on computing technology,
the need for high performance computers (HPC) has significantly
increased. Many performance improvements in conventional
computers are achieved by miniaturizing electronic components
to very small micron-size scale so that electrons need to
travel only short distances within a very short time. This approach
relies on the steadily shrinking trace size on microchips
(i.e., the size of elements that can be ‘drawn’ onto each chip).
This has resulted in the development of Very Large Scale
Integration (VLSI) technology with smaller device dimensions
and greater complexity. The smallest dimensions of VLSI nowadays
are about 0.08 mm. Despite the incredible progress in the
development and refinement of the basic technologies over the
past decade, there is growing concern that these technologies
may not be capable of solving the computing problems of even
the current millennium.
Background
Optical computing was a hot research area in the 1980s. But the
work tapered off because of materials limitations that seemed to
prevent optochips from getting small enough and cheap enough
to be more than laboratory curiosities. Now, optical computers
are back with advances in self-assembled conducting organic
polymers that promise super-tiny all-optical chips [1]. Advances
in optical storage device have generated the promise of
efficient, compact and large-scale storage devices [2]. Another
advantage of optical methods over electronic ones for computing
is that parallel data processing can frequently be done much
more easily and less expensively in optics than in electronics [3].
Some Key Optical Components for Computing
The major breakthroughs on optical computing have been centered
on the development of micro-optic devices for data input.
Conventional lasers are known as ‘edge emitters’ because their
laser light comes out from the edges. Also, their laser cavities
run horizontally along their length. A vertical cavity surface
emitting laser (VCSEL – pronounced ‘vixel’), however, gives
out laser light from its surface and has a laser cavity that is
vertical; hence the name. VCSEL is a semiconductor vertical
cavity surface emitting microlaser diode that emits light in a
cylindrical beam vertically from the surface of a fabricated
wafer, and offers significant advantages when compared to the
edge-emitting lasers currently used in the majority of fiber optic
communications devices. They emit at 850 nm and have rather
low thresholds (typically a few mA).
Uses of Optics in Computing
Currently, optics is used mostly to link portions of computers,
or more intrinsically in devices that have some optical application
or component. For example, much progress has been
achieved, and optical signal processors have been successfully
used, for applications such as synthetic aperture radars, optical
pattern recognition, optical image processing, fingerprint enhancement,
and optical spectrum analyzers. The early work in optical
signal processing and computing was basically analog in nature.
In the past two decades, however, a great deal of effort has
been expended in the development of digital optical processors.