Optical Sources – LED and Laser Diodes

Jun 21 • Notes • 2408 Views • 3 Comments on Optical Sources – LED and Laser Diodes

Optical Sources – LED and Laser Diodes

LED STRUCTURE
– They can be seen glowing green, yellow or red in vehicles, telephones, cameras.
– They are inexpensive and highly reliable light sources.
– The LED used in optical communications are much smaller and emit in the infrared region

MATERIALS:-
– Semiconductor-based light sources are about the size of a grain of salt.
– It allows efficient coupling of the light output in small diameters of fibers.
– They are compatible with integrated-circuit electronics because of its semiconductor structure.

MODULATION OF LED
– It is used for producing a light level which is proportional to some signal.
– The signal can then be send through a fiber optic cable and detected on the other end.
– Then a device produces a current proportional to the input voltage of the applied signal.
– This can be done with the help of an op-amp that acts as a voltage-to-current converter.

 

LASER DIODE:-
– They are the optical sources used in fiber communication systems.
– The four types of lasers are the Fabry-Perot (FP) laser, the distributed-feedback (DFB) laser, tunable lasers and the vertical cavity surface-emitting laser (VCSEL).

EXPECTED QUESTIONS WITH ANSWERS

1) WHAT IS LED AND WHAT ARE THE MATERIALS USED IN LED?

Ans:- – They can be seen glowing green, yellow or red in vehicles, telephones, cameras.
– They are inexpensive and highly reliable light sources.
– The LED used in optical communications are much smaller and emit in the infrared region

MATERIALS:-
– Semiconductor-based light sources are about the size of a grain of salt.
– It allows efficient coupling of the light output in small diameters of fibers.
– They are compatible with integrated-circuit electronics because of its semiconductor structure.

2) HOW IS LED MODULATED?

Ans:- MODULATION OF LED
– It is used for producing a light level which is proportional to some signal.
– The signal can then be send through a fiber optic cable and detected on the other end.
– Then a device produces a current proportional to the input voltage of the applied signal.
– This can be done with the help of an op-amp that acts as a voltage-to-current converter.

3) WHAT ARE LASER DIODE?

Ans:- – They are the optical sources used in fiber communication systems.
– The four types of lasers are the Fabry-Perot (FP) laser, the distributed-feedback (DFB) laser, tunable lasers and the vertical cavity surface-emitting laser (VCSEL).

 

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3 Responses to Optical Sources – LED and Laser Diodes

  1. Palakpuja Panda says:

    its a very impressive note which gives a good outlook on optical sources

  2. Barun Singh says:

    This article clearly explains the different use and method of making them.As LED is mad up of gallium arsenide it has property to conduct both side.Vital information really helpful

  3. Surabhi Singh says:

    Get the idea about Optical Sources through this article .It also carries some questions and answers related with the topics.

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