Integration of Emission-wavelength-controlled InAs Quantum Dots for Ultra-broadband Near-infrared Light Source
Integration of Emission-wavelength-controlled InAs Quantum Dots for Ultra-broadband Near-infrared Light Source
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DOI：
10.5772/59315
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发表时间：
2014-09-29
影响因子：
3.7
通讯作者：
Hogg, Richard A.
中科院分区：
文献类型：
--
作者：
Ozaki, Nobuhiko;Takeuchi, Koichi;Hogg, Richard A.
近红外（NIR）光源由于其在活体组织中的长穿透深度而广泛用于生物和医学成像系统中。在最近开发的生物医学非侵入性横截面成像系统（称为光学相干断层扫描（OCT））中，也需要宽带光谱，因为OCT基于低相干干涉测量法。为了满足这些操作要求，我们已经开发了一个近红外宽带光源集成自组装InAs量子点（量子点）生长在GaAs衬底上（InAs/GaAs量子点）具有不同的发射波长。在这篇综述中，我们介绍了开发的光源和量子点生长技术，用于控制发射波长的宽带发射光谱的中心波长为1.05和1.3 μ m。虽然应变诱导的Stranski-Krastanov（S-K）模式生长的InAs/GaAs量子点通常发射波长约为1.2 μ m的光，但通过使用内冲洗技术、插入应变减小层（SRL）和双层量子点生长技术，可以将中心发射波长控制在0.9-1.4 μ m之间。这些技术是有用的应用InAs/GaAs量子点作为近红外宽带光源，特别是适合于我们提出的光谱形状可控的宽带近红外光源。讨论了这种光源用于提高OCT系统性能的潜力。
Near-infrared (NIR) light sources are widely utilized in biological and medical imaging systems owing to their long penetration depth in living tissues. In a recently developed biomedical non-invasive cross-sectional imaging system, called optical coherence tomography (OCT), a broadband spectrum is also required, because OCT is based on low coherence interferometry. To meet these operational requirements, we have developed a NIR broadband light source by integrating self-assembled InAs quantum dots (QDs) grown on a GaAs substrate (InAs/GaAs QDs) with different emission wavelengths. In this review, we introduce the developed light sources and QD growth techniques that are used to control the emission wavelength for broadband emission spectra with center wavelengths of 1.05 and 1.3 mu m. Although the strain-induced Stranski-Krastanov (S-K) mode-grown InAs/GaAs QDs normally emit light at a wavelength of around 1.2 mu m, the central emission wavelength can be controlled to be between 0.9-1.4 mu m by the use of an In-flush technique, the insertion of a strain-reducing layer (SRL) and bi-layer QD growth techniques. These techniques are useful for applying InAs/GaAs QDs as NIR broadband light sources and are especially suitable for our proposed spectral-shape-controllable broadband NIR light source. The potential of this light source for improving the performance of OCT systems is discussed.