Accession Number : ADA624515


Title :   Mode-locking of an InAs Quantum Dot Based Vertical External Cavity Surface Emitting Laser Using Atomic Layer Graphene


Descriptive Note : Final rept. 20 Jan 2012-19 Jan 2015


Corporate Author : NEW MEXICO UNIV ALBUQUERQUE


Personal Author(s) : Balakrishnan, Ganesh


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a624515.pdf


Report Date : 16 Jul 2015


Pagination or Media Count : 22


Abstract : The InAs quantum dot (QD) grown on GaAs substrates represents a highly performance active region in the 1 - 1.3(mu) m wavelength range. The use of such QDs in vertical-cavity devices has resulted in high-power and broad gain bandwidth VECSELs in the NIR. In this project we demonstrate growth and design of InAs QD based VECSELs in the 1200 -1300 nm wavelength range with record CW output powers. We utilize a resonant periodic gain (RPG) structure with a single QD layer per standing wave antinode to effectively increase the distance between strained layers to improve the quality of the active region. We compare the performance of a VECSEL with 12 separate QD layers (12x1 structure) to a more traditional design that uses 4 groups of 3 closely spaced QD layers (4x3). The experimental performance of the 12x1 device is superior to the 4x3 structure in terms of threshold pump power, differential efficiency, and maximum output power. For thermal management, the GaAs wafer of the 12x1 structure was thinned by mechanical polishing, and indium was used to mount the gain mirror on a thermal-grade chemical vapor deposition (CVD) diamond, allowing for over 6 W of CW output power, which is a record result for stranski-krastanov based quantum dots.


Descriptors :   *QUANTUM DOTS , *VERTICAL CAVITY SURFACE EMITTING LASERS , BROADBAND , CHEMICAL VAPOR DEPOSITION , CONTINUOUS WAVES , EFFICIENCY , GALLIUM ARSENIDES , INDIUM ARSENIDES , SUBSTRATES , TEMPERATURE CONTROL , WAFERS


Subject Categories : Lasers and Masers
      Quantum Theory and Relativity


Distribution Statement : APPROVED FOR PUBLIC RELEASE