title: Investigation of Semiconductor Quantum Dots for Waveguide Electroabsorption Modulator.
abstract: In this work, we investigated the use of 10-layer InAs quantum dot (QD) as active region of an electroabsorption modulator (EAM). The QD-EAM is a p-i-n ridge waveguide structure with intrinsic layer thickness of 0.4 mum, width of 10 mum, and length of 1.0 mm. Photocurrent measurement reveals a Stark shift of ~5 meV (~7 nm) at reverse bias of 3 V (75 kV/cm) and broadening of the resonance peak due to field ionization of electrons and holes was observed for E-field larger than 25 kV/cm. Investigation at wavelength range of 1,300-1320 nm reveals that the largest absorption change occurs at 1317 nm. Optical transmission measurement at this wavelength shows insertion loss of ~8 dB, and extinction ratio of ~5 dB at reverse bias of 5 V. Consequently, methods to improve the performance of the QD-EAM are proposed. We believe that QDs are promising for EAM and the performance of QD-EAM will improve with increasing research efforts.
authors.forename: C Y
authors.initials: CY
authors.lastname: Ngo
authors.forename: S F
authors.initials: SF
authors.lastname: Yoon
authors.forename: W K
authors.initials: WK
authors.lastname: Loke
authors.forename: Q
authors.initials: Q
authors.lastname: Cao
authors.forename: D R
authors.initials: DR
authors.lastname: Lim
authors.forename: Vincent
authors.initials: V
authors.lastname: Wong
authors.forename: Y K
authors.initials: YK
authors.lastname: Sim
authors.forename: S J
authors.initials: SJ
authors.lastname: Chua