Feature Of The Week 2/22/09: Self-Assembled Quantum Dots for High-Performance Broadband Optical Coherence Tomography Sources
Feature Of The Week 2/22/09: The development of low-cost, compact, and high-power broadband sources for OCT applications is a very interesting research area being pursued in a number of research laboratories and companies around the world. Superluminescent light emiting diodes (SLEDs), in particular, have made tremendous progress towards a commercializable low-cost source for point of care screening and diagnostics OCT systems. Self-assembled quantum dots (SAQD) are a new and exciting class of nanomaterials which are leading to a revolution in the development of high power and broadband SLEDs, most recently by utilizing their natural broad emission spectra due to the large dot sizes inhomogeneity. Dr. Ziyang Zhang et al from the University of Sheffield have done a lot of interesting work on the investigation of high performance QD-SLEDs. In his most recent publications, post-growth annealed multiple SAQD layer structures are demonstrated as very effective in fabricating broadband QD-SLEDs. This figure contains two images corresponding to two kinds of L-I curves and emission spectra of two different QD-SLEDs: one is working at around 1 µm and the other is at around 1.3 µm. One device exhibits a 3 dB emission bandwidth of 146 nm centered at 984 nm with cw output power as high as 15 mW at room temperature corresponding to an small coherence length of 6.6 µm. Another device in the 1.3 µm range exhibits a large and flat emission with spectral width up to 132 nm at 2 mW. For more information, please see article 1 and article 2. Submit your image using feedback link below.