tailieunhanh - Báo cáo hóa học: " Investigation of Semiconductor Quantum Dots for Waveguide Electroabsorption Modula"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Investigation of Semiconductor Quantum Dots for Waveguide Electroabsorption Modula | Nanoscale Res Lett 2008 3 486-490 DOI S11671-008-9184-7 NANO EXPRESS Investigation of Semiconductor Quantum Dots for Waveguide Electroabsorption Modulator C. Y. Ngo S. F. Yoon W. K. Loke Q. Cao D. R. Lim Vincent Wong Y. K. Sim S. J. Chua Received 27 July 2008 Accepted 2 October 2008 Published online 21 October 2008 to the authors 2008 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 m width of 10 m and length of 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. Keywords InAs quantum dots Electroabsorption modulator Ridge waveguide structure Photocurrent Optical transmission C. Y. Ngo H S. F. Yoon W. K. Loke Q. Cao D. R. Lim School of Electrical and Electronic Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore e-mail ngoc0003@ V. Wong Y. K. Sim Temasek Laboratories @ NTU Nanyang Technological University 50 Nanyang Drive Singapore 639798 Singapore S. J. Chua Institute of Materials Research and Engineering 3 Research Link Singapore 117602 Singapore Introduction Semiconductor quantum dots QDs is attracting tremendous research interests due to the benefits promised by the three-dimensional 3D carrier confinement of the QD system. For