# OPTICAL RECEIVER AND ITS COHERENT DETECTION

Jun 17 • Notes • 4579 Views • 2 Comments on OPTICAL RECEIVER AND ITS COHERENT DETECTION

OPTICAL RECEIVER AND ITS COHERENT DETECTION

-The main components of an optical receiver is a photo detector which is used for the amplification and processing of signals.
-Various noises and distortions are introduced due to imperfect component responses.
– This leads to errors in the interpretation of the received signal

-The performance of an optical receiver is measured in terms of the average error probability.

-The calculation of the error probability for a digital optical communication receiver is different from the signal to noise ratio of an analog receiver.

EYE DIAGRAM:-

-The data-handling ability of a digital transmission system is measured with the help of an eye diagram.

-The width of an eye opening determines the time over which the signal can be sampled in order to prevent the intersymbol interference.

-The best time for the sampling of the received signal is when the height of the eye opening is largest.

-The height of the eye opening gives the measure of  immunity to noise.

COHERENT DETECTION:-

– The principle of coherent detection is combining the optical signal coherently with a continuous-wave (CW) optical field.

–  The receiver performance in the optical signal is written as
Es = As exp[−i(ω0t +φs)]

– There are two types of coherent detection techniques-
1) HOMODYNE DETECTION
2) HETERODYNE DETECTION

EXPECTED QUESTION WITH ANSWERS:-

1)      WHAT DO YOU MEAN BY OPTICAL RECEIVER?

Ans:- The main components of an optical receiver is a photodetector which is used for the amplification and processing of signals.

Various noises and distortions are introduced due to imperfect component responses.
This leads to errors in the interpretation of the received signal

-The performance of an optical receiver is measured in terms of the average error probability.

-The calculation of the error probability for a digital optical communication receiver is different from the signal to noise ratio of an analog receiver.

2)      WHAT IS AN EYE DIAGRAM?

Ans:- The data-handling ability of a digital transmission system is measured with the help of an eye diagram.

-The width of an eye opening determines the time over which the signal can be sampled in order to prevent the intersymbol interference.

-The best time for the sampling of the received signal is when the height of the eye opening is largest.

-The height of the eye opening gives the measure of  immunity to noise.

3)      WHAT IS COHERENT DETECTION?

Ans:- – The principle of coherent detection is combining the optical signal coherently with a continuous-wave (CW) optical field.

GATE Syllabus-

IES Syllabus-

### 2 Responses to OPTICAL RECEIVER AND ITS COHERENT DETECTION

1. Dinesh says:

Excellent article done wont to read the article the pictures itself told everything., special appreciation for the picture choosing skill. nice way the article was molted

2. shweta singh says:

The article is sufficient to provide enough knowledge about the optical receiver and its type of the detection…the proper knowledge can be gained about this topic 🙂