4.10 Heterostructure Laser Diode
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In order to lower I ,
th
Double Heterojunction (DH)
1.
Limit injected electron-hole to the
active region, thus less current is
required to establish N > N .
2
1
(Carrier confinement)
Made by specific materials/structures,
not homojunction anymore.
2.
Confine photons in the active region,
thus reduced photon loss outside
cavity.
(Optical confinement)
Made by two lower n materials to
sandwich a higher n material.

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