A tecnologia envolvida na criação e desenvolvimento de dispositivos baseados em pontos quânticos ainda tem um longo caminho a percorrer, pelo que são muitas as direcções que podem ser seguidas em termos de estudo e investigação deste tipo de dispositivos. No seguimento do trabalho realizado para a concretização desta dissertação, são propostas algumas sugestões de trabalho futuro:
• Implementação de um simulador baseado em modelos de várias populações de pontos quânticos, MPREM.
• Estudo da sensibilidade de cada modelo de QD-SOAs a variações dos diferentes parâmetros envolvidos.
• Desenvolvimento de modelos simplificados para aplicações especificas, de forma a tornar a sua implementação computacional menos exigente.
• Continuação do estudo das aplicações estudadas, bem como o estudo de novas aplicações com QD-SOAs.
• Comparação e validação dos resultados determinados por simulação com resultados experimentais.
Estas são apenas algumas das muitas sugestões de trabalhos que podem ser realizados no seguimento desta tese.
Apêndice – Parâmetros dos modelos
Tabelas com os valores dos parâmetros dos modelos de QD-SOAs utilizados na construção dos simuladores.
Símbolo Descrição Valor
W Largura da região activa 3×10-6 m
L Comprimento da região activa 1×10-3 m
H Altura da região activa 0.2×10-6 m
L
H Espessura da wetting layer 1×10-9 m
D
N Densidade volumétrica de pontos quânticos 2×1021 m-3
D
V Volume de um ponto quântico 2.3×10-24 m3
l
n Número de camadas de pontos quânticos 3
wg
τ Tempo médio de captura da wetting layer para o estado fundamental 2×10-12 s
r
τ Tempo médio de recombinação espontânea nos pontos quânticos 1×10-9 s
sr
τ Tempo médio de recombinação espontânea na wetting layer 0.2×10-9 s
max
g Ganho modal máximo 12×102 m-1
loss
α Perdas internas 2×102 m-1
e
m Massa efectiva dos electrões 0.026m0
h
m Massa efectiva das lacunas 0.074m0
g
ε Degenerância do estado fundamental 2
hom
E Largura a meia altura do alargamento espectral homogéneo 5 meV
hom
n
E − Largura a meia altura do alargamento espectral não homogéneo 40 meV
w g
c c
E −E Diferença de energia entre a wetting layer e o estado fundamental 100 meV
g v
E Energia do nível mais elevado na banda de condução dos pontos quânticos 42 meV
w v
Símbolo Descrição Valor
W Largura da região activa 10×10-6 m
L Comprimento da região activa 2×10-3 m
H Altura da região activa 0.2×10-6 m
D
N Densidade de pontos quânticos 3.8×1022 m-3
D
V Volume de um ponto quântico 2.3×10-24 m3
we
τ Tempo médio de captura 3×10-12 s
ew
τ Tempo médio de escape do estado excitado para a wetting layer 1×10-9 s
eg
τ Tempo médio de relaxação do estado excitado para o estado fundamental 0.16×10-12 s
ge
τ Tempo médio de excitação do estado fundamental para o estado excitado 1.2×10-12 s
r
τ Tempo médio de recombinação espontânea nos pontos quânticos 1×10-9 s
sr
τ Tempo médio de recombinação espontânea na wetting layer 0.2×10-9 s
max
g Ganho modal máximo 11.5×102 m-1
loss
α Perdas internas 3×102 m-1
α
Factor de alargamento espectral 1λ Comprimento de onda 1.55×10-6 m
n Índice de refracção 3.5
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