# OPTICAL RECEIVER AND ITS COHERENT DETECTION

Jun 17 • Notes • 4627 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

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.

-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: