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Faculty of Sciences
Document Details
Document Type
:
Article In Journal
Document Title
:
Influence of pseudorandom bit format on the direct modulation performance of semiconductor lasers
Influence of pseudorandom bit format on the direct modulation performance of semiconductor lasers
Subject
:
physics
Document Language
:
English
Abstract
:
This paper investigates the direct gigabit modulation characteristics of semiconductor lasers using the return to zero (RZ) and non-return to zero (NRZ) formats. The modulation characteristics include the frequency chirp, eye diagram, and turn-on jitter (TOJ). The differences in the relative contributions of the intrinsic noise of the laser and the pseudorandom bit-pattern effect to the modulation characteristics are presented. We introduce an approximate estimation to the transient properties that control the digital modulation performance, namely, the modulation bit rate and the minimum (setting) bit rate required to yield a modulated laser signal free from the bit pattern effect. The results showed that the frequency chirp increases with the increase of the modulation current under both RZ and NRZ formats, and decreases remarkably with the increase of the bias current. The chirp is higher under the RZ modulation format than under the NRZ format. When the modulation bit rate is higher than the setting bit rate of the relaxation oscillation, the laser exhibits enhanced TOJ and the eye diagram is partially closed. TOJ decreases with the increase of the bias and/or modulation current for both formats of modulation.
ISSN
:
0304-4289
Journal Name
:
PRAMANA-JOURNAL OF PHYSICS
Volume
:
79
Issue Number
:
6
Publishing Year
:
1433 AH
2012 AD
Article Type
:
Article
Added Date
:
Thursday, July 20, 2017
Researchers
Researcher Name (Arabic)
Researcher Name (English)
Researcher Type
Dr Grade
Email
Moustafa Ahmed
Ahmed, Moustafa
Investigator
Doctorate
mostafa.hafez@science.miniauniv.edu.eg
Safwat Mahmoud
Mahmoud, Safwat
Researcher
Doctorate
Alaa Mahmoud
Mahmoud, Alaa
Researcher
Files
File Name
Type
Description
42149.pdf
pdf
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