Optoelectronics
Optoelectronics
Optoelectronics
device
and
optoelectronic
sensor
Optoelectronic device
In the scientific context, Optoelectronics deals with the study and application of electronic devices that interact
with light i.e. the detection of light, its creation, and exploitation for several purposes. This includes Gamma rays,
X-rays, Ultraviolet, Infrared and visible light. Optoelectronics is the communication between optics and
electronics which also encompasses the study, design, and manufacture of hardware apparatus that facilitate the
conversion of electricity into photon signals. This device is made from solid crystalline materials which are
lighter than metals and heavier than insulators. This device can be found in many optoelectronics applications like
military services, telecommunications, automatic access control systems, and medical equipment.
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types
Optoelectronics are classified into different types such as
• Photodiode
• Solar Cells
• Light Emitting Diodes
• Optical Fiber
• Laser Diodes
photodiode
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Solar cells
A solar cell or photovoltaic cell is an electronic device that
directly converts the sun’s energy into electricity. When
sunlight falls on a solar cell, it produces both a current and a
voltage to produce electric power. Sunlight, which is composed
of photons, radiates from the sun. When photons hit the silicon
atoms of the solar cell, they transfer their energy to lose
electrons; then, these high-energy electron flow to an external
circuit.
The solar cell is composed of two layers that are struck
together. The first layer is loaded with electrons, so these
electrons are ready to jump from the first layer to the second
layer. The second layer has some electrons taken away, and
therefore, it is ready to take more electrons. The advantages of
solar cells are that there is no fuel supply and cost problems.
These are very dependable and require little maintenance.
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Light-emitting diodes
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Optical fiber
An optical fiber or optic fiber is a plastic and For example, an orange-color cable
transparent fiber made of plastic or glass. It is clearly indicates a single-mode fiber,
somewhat thicker than a human hair. It can function while a yellow one indicates
as a light pipe or waveguide to transmit light a multimode fiber. In the single-mode
between the two ends of the fiber. Optical fibers fiber, one mode propagates and the
usually include three concentric layers: a core, a light rays travel straight through the
cladding and a jacket. The core, a light transmitting cable. In a multimode cable, the light
region of the fiber, is the central section of the fiber, rays travel through the cable following
which is made of silica. Cladding, the protective different modes.
layer around the core, is made of silica. This creates
The advantages of using optical-fiber
an optical waveguide that limits the light in the core
cables include their higher bandwidth,
by total reflection at the interface of the core-
less signal degradation, weightlessness
cladding. Jacket, the non-optical layer around the
and thinness than copper wire, cost-
cladding, typically consists of one or more layers of
effectiveness, and flexibility, hence
a polymer that protect the silica from the physical or
they are used in medical and
environmental damage.
mechanical imaging systems.
Along with the fiber-optic cable, jackets are
available in different colors. These colors allow the
recognition of the fiber-optic cable and the type of
cable one is dealing with.
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Laser diodes
Laser (light amplification by stimulated emission of radiation) is a source of highly monochromatic, coherent and directional
light. It operates under stimulated emission conditions. The function of a laser diode is to convert electrical energy into light
energy like infrared diodes or LEDs. The beam of a typical laser has 4×0.6mm extending at a distance of 15 meters. The
most common lasers used are injection lasers or semiconductor lasers. The semiconductor laser changes from other lasers
like solid, liquid and gas lasers.
When a voltage is applied across the P-N junction, the population inversion of the electrons is produced, and then the laser
beam is available from the semiconductor region. The ends of the P-N junction of the laser diode have polished surfaces, and
hence, the emitted photons reflect back to create more electron pairs. Thus, the photons generated will be in phase with the
previous photons.
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Applications of optoelectronic devices
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Applications of optoelectronic devices
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Applications of optoelectronic devices
Photodiodes are used in many types of circuits and different applications such as
cameras, medical instruments, safety equipment, industries, communication devices, and
industrial equipment.
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Optoelectronic sensors
Integrated optoelectronic sensors are designed to respond Linear sensor arrays Measure spatial relationships
and light intensity
to light so that they can recognize things such as
patterns, images, motion, intensity, and color. The Color sensors RGB (red/green/blue) filtered
sensor's ability to perform this recognition (and the sensors for color
complexity of the recognition possible) depends upon discrimination, determination,
and measurement
Reflective light sensors Convert reflective light
intensity to a voltage output
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Application in the medical field
All of these types of sensors can be, and are, used Current medical applications
in medical equipment applications. They help that use optoelectronic sensors
eliminate human error while providing more include:
accurate readings and faster results. Rather than • pulse oximetry, measuring
rely on human judgment to match colors or the amount of oxygen in the
identify changes in light intensity, the sensors are blood;
designed to read or measure light— a real-world • heart-rate monitors;
signal considered to be very stable and highly • blood diagnostics, such as
accurate—in a reliable, repeatable way. Data from blood glucose monitoring;
the optoelectronic measurements are fed directly • urine analysis; and d Figure 1. Pulse oximetry measures the
into the computer system, removing another • ental color matching. percentage of hemoglobin (Hb)
possible source of error. The sensors are saturated with oxygen by measuring
the absorption of red and IR light
noncontact, able to perform their sensing or
passed through a patient's finger (as
measurement functions without the need for shown here) or ear lobe. Knowing
physical contact with specimens such as blood, what percentage of the hemoglobin is
urine, or other bodily fluids. This is critical saturated with oxygen is important
because if the specimens are tainted in any way, when administering anesthesia or for
the resulting readings and measurements may not determining the effectiveness of the
respiratory system, as well as for
be accurate. helping diagnose various illnesses.
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end
LINK SOURCES
https://
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https:// components/optoelectronic-
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