Influence of mode confinement factor on the modulation properties of the Vertical Cavity Surface Emitting VCSEL laser

Afrah Kareem,Younis Qurot

doi:10.33899/edusj.2021.130566.1169

Abstract

Vertical cavity surface emitting laser VCSEL is currently the main solution for many technological aspects, ultrafast optical interconnecting, Gigabit Ethernet, etc. In this paper we present the simulation results by using Optiwave™ software version 7, of the effects of optical mode confinement factor on the modulation properties)which inspected by eye diagram of the received signals)of the vertical cavity surface emitting laser VCSEL, with the range (8-20)Gbps of pseudo random bit sequence PRBS. The quality of the VCSEL modulation have been inspected by time domain signals, spectrums and eye diagram. Simulation results appeared an improvement in the characteristics of received bit sequences of (8, 10, 12.5, 16 and 20)Gbps bit rates, represented by the rising the value of quality factor QF (1.77 to 4.81) versus increasing the value of optical mode confinement factor Γ(0.2 to 0.5) respectively, and a decreasing in jitter time of superimposed traces of eye pattern and well opining eye pattern. And in the corresponding, the bit error rates BERs of the received signals have been decreased, with rising the value of mode confinement factor Γ of the laser at constant modulation index and constant temperature of the laser. Also, the VCSEL’s modulation response differences with different bitrates, causes different values of QF and BER for individual value of mode confinement factor Γ.

Highlights

During the past three decades, vertical cavity surface emitting lasers VCSEL, became the powerful tool in utilizing in many technology fields [1], e.g. over 10Gb/s data rate transceiver fiber optic communications [2][3], avionic Gigabit full duplex Ethernet [4], high resolution-fast printers [5], high performance computing (HPC) hardware [6] biomedical imaging and sensing [10]
We proposed direct modulation of VCSEL with many Gbps bitrate of the non-return to zero(NRZ) pseudo random bit sequence PRBS signals and investigating by the simulation using OptiwaveTM software, the influence of the mode confinement factor on the modulation characteristics, e.g. on time domain signal, modulated carrier spectrum and received eye diagrams
In order to investigate the role of the optical confinement factor Γ on the modulation characteristics of VCSEL, the value of Γ is changed on each new program execution with the rest other parameters of the VCSEL and bitrate being fixed

Summary

Introduction

During the past three decades, vertical cavity surface emitting lasers VCSEL, became the powerful tool in utilizing in many technology fields [1], e.g. over 10Gb/s data rate transceiver fiber optic communications [2][3], avionic Gigabit full duplex Ethernet [4], high resolution-fast printers [5], high performance computing (HPC) hardware [6] biomedical imaging and sensing [10]. We proposed direct modulation of VCSEL with many Gbps bitrate of the non-return to zero(NRZ) pseudo random bit sequence PRBS signals and investigating by the simulation using OptiwaveTM software, the influence of the mode confinement factor on the modulation characteristics, e.g. on time domain signal, modulated carrier spectrum and received eye diagrams. The transmission characteristics such as modulated and optical carrier signals, their spectrums, received signal, spectrum, received power and eye diagram have been recorded. That is because of the connection between transmitter and the receiver take place via loss free transmission medium, which prevent the transmitted signals from the losses distortion

Impacts of optical confinement factor Γ on VCSEL transmission

Conclusion