PHOTONICS DEVICES

Introduction of Photonics Devices :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.

 

Light-Emitting Diodes

.

Introduction of LEDs :A  Light-emitting Diodes  is a semiconductor light source. LEDs areused as indicator lamps. In many devices, and are increasingly usedfor lighting.

Properties of LEDs :  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 .

 

Construction of LEDs : 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.

Figure:

PHOTO DIODES

Introduction of Photo Diode :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.

Properties of Photo Diode: 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.

Construction of Photo Diode:

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.

Figure:

Laser Diode

Introduction of Laser Diode:

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.

Properties of Laser Diode:

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 requirements3- Low intensity: A laser diode cannot be used spectacular purposes. such as burning holes in metal, bringing down satellites.

 

Construction of Laser Diode: Laser diode is completely solid state and do not require fragile glass elements.

It is formed by doping  a very thin layer on the surface of a crystal type wafer. The crystal is doped to produce an n-type  region and a p-  region, one above the other, resulting in a p-n junction, or diode.A power supply for energizing the laser diode pump source.

Figure:

Prepared By:

Molhum Mohammed Hamed 115002

Mohammed Essam Mohammed 115057

Mohammed Abdo Mohammed 115059

Amr Aidross Abdullah 115081

Ziad Ahmed 115084