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DBR-free optically pumped semiconductor disk lasers

Proceedings of SPIE - The International Society for Optical Engineering

Yang, Zhou; Albrecht, Alexander R.; Cederberg, Jeffrey G.; Sheik-Bahae, Mansoor

Optically pumped semiconductor disk lasers (SDLs) provide high beam quality with high average-power power at designer wavelengths. However, material choices are limited by the need for a distributed Bragg reflector (DBR), usually monolithically integrated with the active region. We demonstrate DBR-free SDL active regions, which have been lifted off and bonded to various transparent substrates. For an InGaAs multi-quantum well sample bonded to a diamond window heat spreader, we achieved CW lasing with an output power of 2 W at 1150 nm with good beam quality.

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TYPE Conference Poster YEAR 2015
ScopusOSTI

Growth and testing of vertical external cavity surface emitting lasers (VECSELs) for intracavity cooling of Yb:YLF

Journal of Crystal Growth

Cederberg, Jeffrey G.; Albrecht, A.R.; Ghasemkhani, M.; Melgaard, S.D.; Sheik-Bahae, M.

Optically-pumped vertical external cavity surface emitting lasers (VECSELs) have unique characteristics that make them attractive for use in intracavity optical cooling of rare earth doped crystals. We present the development of high power VECSELs at 1020 nm for cooling ytterbium-doped yttrium lithium fluoride (Yb:YLF). The VECSEL structures use AlAs/GaAs distributed Bragg reflectors and InGaAs/GaAsP resonant periodic gain epitaxially grown by metal-organic vapor phase epitaxy. To achieve the necessary output power, we investigated thinning the substrate to improve the thermal characteristics. We demonstrated a VECSEL structure that was grown inverted, bonded to the heat sink, and the substrate removed by chemical etching. The inverted structure allows us to demonstrate 15 W output with 27% slope efficiency. Wavelength tuning of 30 nm around 1020 nm was achieved by inserting a birefringent quartz window into the cavity. The window also narrows the VECSEL emission, going from a FWHM of 5 nm to below 0.5 nm at a pump power of 40 W. © 2013 Published by Elsevier B.V.

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TYPE Conference YEAR 2014
ScopusOSTI

Non-abelian fractional quantum hall effect for fault-resistant topological quantum computation

Pan, Wei P.; Shi, Xiaoyan S.; Crawford, Matthew D.; Nielsen, Erik N.; Cederberg, Jeffrey G.

Topological quantum computation (TQC) has emerged as one of the most promising approaches to quantum computation. Under this approach, the topological properties of a non-Abelian quantum system, which are insensitive to local perturbations, are utilized to process and transport quantum information. The encoded information can be protected and rendered immune from nearly all environmental decoherence processes without additional error-correction. It is believed that the low energy excitations of the so-called =5/2 fractional quantum Hall (FQH) state may obey non-Abelian statistics. Our goal is to explore this novel FQH state and to understand and create a scientific foundation of this quantum matter state for the emerging TQC technology. We present in this report the results from a coherent study that focused on obtaining a knowledge base of the physics that underpins TQC. We first present the results of bulk transport properties, including the nature of disorder on the 5/2 state and spin transitions in the second Landau level. We then describe the development and application of edge tunneling techniques to quantify and understand the quasiparticle physics of the 5/2 state.

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TYPE SAND Report YEAR 2013
OSTIDOI

Flat plate concentrators with large acceptance angle enabled by micro cells and mini lenses: performance evaluation

Cruz-Campa, Jose L.; Anderson, Benjamin J.; Gupta, Vipin P.; Tauke-Pedretti, Anna; Cederberg, Jeffrey G.; Paap, Scott M.; Sanchez, Carlos A.; Nordquist, Christopher N.; Nielson, Gregory N.; Saavedra, Michael P.; Ballance, Mark H.; Nguyen, Janet N.; Alford, Charles A.; Riley, Daniel R.; Okandan, Murat O.; Lentine, Anthony L.; Sweatt, W.C.; Jared, Bradley H.; Resnick, Paul J.; Kratochvil, Jay A.

Abstract not provided.

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TYPE Conference YEAR 2013
OSTI

Advanced compound semiconductor and silicon fabrication techniques for next-generation solar power systems

ECS Transactions

Nielson, Gregory N.; Okandan, Murat O.; Cruz-Campa, Jose L.; Gupta, Vipin P.; Resnick, Paul J.; Sanchez, Carlos A.; Paap, Scott M.; Kim, B.; Sweatt, W.C.; Lentine, Anthony L.; Cederberg, Jeffrey G.; Tauke-Pedretti, Anna; Jared, B.H.; Anderson, Benjamin J.; Biefeld, Robert M.; Nelson, J.S.

Microsystem technologies have the potential to significantly improve the performance, reduce the cost, and extend the capabilities of solar power systems. These benefits are possible due to a number of significant beneficial scaling effects within solar cells, modules, and systems that are manifested as the size of solar cells decrease to the sub-millimeter range. To exploit these benefits, we are using advanced fabrication techniques to create solar cells from a variety of compound semiconductors and silicon that have lateral dimensions of 250 - 1000 μm and are 1 - 20 μm thick. These fabrication techniques come out of relatively mature microsystem technologies such as integrated circuits (IC) and microelectromechanical systems (MEMS) which provide added supply chain and scale-up benefits compared to even incumbent PV technologies. © The Electrochemical Society.

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TYPE Conference YEAR 2013
ScopusOSTI
Results 1–25 of 63
Results 1–25 of 63