2. Photonics is the transmission, control, manipulation and storage of data
using photons (the basic building blocks of light).
The unique characteristics of photonic devices create an additional
dimension energy saving and larger communication distances. In
addition, photonic devices are less sensitive to interference and have
unique physical characteristics.
4. A Light-emitting Diodes is a semiconductor light source. LEDs are
used as indicator lamps. In many devices, and are increasingly used
for lighting. .
LED is often small in area (less than 1 mm2 ) .
It presents many advantages over bright light sources
including lower energy consumption, longer life time,
Smaller size and fast switching .
5. LEDS are poor diodes usually made from gallium arsenide. With the
proper voltage and current it will emit photons at some variable
frequency in small visual spectrum whereby it can visually be seen with
our eyes in difference colors in the visual spectrum.
7. Photodiodes are PN junction diodes designed specifically to prove the
photoelectric effect. This means the device show the junction region of
the PN diode to incoming photons which results in conducting the
transfer of electrons across the junction.
1-The active area, i.e., the light-sensitive area .
2-The maximum allowed photocurrent (usually limited by saturation).
3-The dark current (The current through the photodiode in the absence
of light, when it is operated in photoconductive mode).
4-The photocurrent divided by optical power –related to the quantum
efficiency, dependent on the wavelength .
8. A photodiode is a p-n junction ,When a photon of sufficient energy
strikes the diode, it excites an electron, thereby creating a free electrons
(and a positively charged electron hole). This mechanism is also known
as the inner photoelectric effect .
10. A laser diode is a component that converts an electrical signal
into a corresponding light signal.
A laser diode a semi conductor device that produces coherent radiation
in the visible or infrared (IR) spectrum when current passes through it.
1- Small size and weight: A typical laser diode measures less than one
millimeter across and weighs a fraction of a gram.
2- Low current, voltage, and power requirements
3- Low intensity: A laser diode cannot be used spectacular purposes.
such as burning holes in metal, bringing down satellites.
11. Laser diode is completely solid state and do not require fragile glass
It is formed by doping a very thin layer on the surface of a crystal
wafer. The crystal is doped to produce an n-type region and a p- type
region, one above the other, resulting in a p-n junction, or diode.
A power supply for energizing the laser diode pump source.
12. Molhum Mohammed Hamed 115002
Mohammed Essam Mohammed 115057
Mohammed Abdo Mohammed 115059
Amr Aidross Abdullah 115081
Ziad Ahmed 115084