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Ultra-fast diffractive optical micro-trap arrays for neutral atom quantum computing

Proceedings of SPIE - The International Society for Optical Engineering

Kemme, S.A.; Brady, G.R.; Ellis, A.R.; Wendt, J.R.; Peters, D.W.; Biedermann, Grant B.; Carter, T.R.; Samora, S.; Isaacs, J.A.; Ivanov, V.V.; Saffman, M.

We design and fabricate arrays of diffractive optical elements (DOEs) to realize neutral atom micro-traps for quantum computing. We initialize a single atom at each site of an array of optical tweezer traps for a customized spatial configuration. Each optical trapping volume is tailored to ensure only one or zero trapped atoms. Specifically designed DOEs can define an arbitrary optical trap array for initialization and improve collection efficiency in readout by introducing high-numerical aperture, low-profile optical elements into the vacuum environment. We will discuss design and fabrication details of ultra-fast collection DOEs integrated monolithically and coaxially with tailored DOEs that establish an optical array of micro-traps through far-field propagation. DOEs, as mode converters, modify the lateral field at the front focal plane of an optical assembly and transform it to the desired field pattern at the back focal plane of the optical assembly. We manipulate the light employing coherent or incoherent addition with judicious placement of phase and amplitude at the lens plane. This is realized through a series of patterning, etching, and depositing material on the lens substrate. The trap diameter, when this far-field propagation approach is employed, goes as 2.44λF/#, where the F/# is the focal length divided by the diameter of the lens aperture. The 8-level collection lens elements in this presentation are, to our knowledge, the fastest diffractive elements realized; ranging from F/1 down to F/0.025. © 2012 SPIE.

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High precision fabrication of polarization insensitive resonant grating filters

Proceedings of SPIE - The International Society for Optical Engineering

Boye, R.R.; Peters, D.W.; Wendt, J.R.; Samora, S.; Stevens, Jeffrey S.; Shul, Randy J.; Hunker, J.; Kellogg, Rick A.; Kemme, S.A.

Resonant subwavelength gratings have been designed and fabricated as wavelength-specific reflectors for application as a rotary position encoder utilizing ebeam based photolithography. The first grating design used a two-dimensional layout to provide polarization insensitivity with separate layers for the grating and waveguide. The resulting devices had excellent pattern fidelity and the resonance peaks and widths closely matched the expected results. Unfortunately, the gratings were particularly angle sensitive and etch depth errors led to shifts in the center wavelength of the resonances. A second design iteration resulted in a double grating period to reduce the angle sensitivity as well as different materials and geometry; the grating and waveguide being the same layer. The inclusion of etch stop layers provided more accurate etch depths; however, the tolerance to changes in the grating duty cycle was much tighter. Results from these devices show the effects of small errors in the pattern fidelity. The fabrication process flows for both iterations of devices will be reviewed as well as the performance of the fabricated devices. A discussion of the relative merits of the various design choices provides insight into the importance of fabrication considerations during the design stage. © 2012 SPIE.

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A Summary of the Theory and Design Team Efforts for the Sandia Metamaterials Science and Technology Grand Challenge LDRD

Basilio, Lorena I.; Brener, Igal B.; Burckel, David B.; Shaner, Eric A.; Wendt, J.R.; Luk, Ting S.; Ellis, A.R.; Bender, Daniel A.; Clem, Paul G.; Rasberry, Roger D.; Langston, William L.; Ihlefeld, Jon I.; Dirk, Shawn M.; Warne, Larry K.; Peters, D.W.; El-Kady, I.; Reinke, Charles M.; Loui, Hung L.; Williams, Jeffery T.; Sinclair, Michael B.; McCormick, Frederick B.

Abstract not provided.

Nanoantenna-enabled midwave infrared focal plane arrays

Proceedings of SPIE - The International Society for Optical Engineering

Peters, D.W.; Reinke, Charles M.; Davids, Paul D.; Klem, John F.; Leonhardt, Darin L.; Wendt, J.R.; Kim, Jin K.; Samora, S.

We demonstrate the effects of integrating a nanoantenna to a midwave infrared (MWIR) focal plane array (FPA). We model an antenna-coupled photodetector with a nanoantenna fabricated in close proximity to the active material of a photodetector. This proximity allows us to take advantage of the concentrated plasmonic fields of the nanoantenna. The role of the nanoantenna is to convert free-space plane waves into surface plasmons bound to a patterned metal surface. These plasmonic fields are concentrated in a small volume near the metal surface. Field concentration allows for a thinner layer of absorbing material to be used in the photodetector design and promises improvements in cutoff wavelength and dark current (higher operating temperature). While the nanoantenna concept may be applied to any active photodetector material, we chose to integrate the nanoantenna with an InAsSb photodiode. The geometry of the nanoantenna-coupled detector is optimized to give maximal carrier generation in the active region of the photodiode, and fabrication processes must be altered to accommodate the nanoantenna structure. The intensity profiles and the carrier generation rates in the photodetector active layers are determined by finite element method simulations, and iteration between optical nanoantenna simulation and detector modeling is used to optimize the device structure. © 2012 SPIE.

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Multilayer infrared metamaterial fabrication using membrane projection lithography

Journal of Vacuum Science and Technology. B, Nanotechnology and Microelectronics

Wendt, J.R.; Brener, Igal B.; Sinclair, Michael B.

Membrane projection lithography is extended from a single layer fabrication technique to a multilayer process, adding polymeric backfill and planarization after each layer is completed. Unaligned contact lithography is used as a rapid prototyping tool to aid in process development, patterning resist membranes in seconds without requiring long e-beam write times. The fabricated multilayer structures show good resistance to solvent attack from subsequent process steps and demonstrate in-plane and out of plane multilayer metallic inclusions in a dielectric host, which is a critical step in the path to develop bulklike metamaterials at optical frequencies.

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Interaction between metamaterial resonators and inter-subband transitions in quantum wells

2011 Conference on Lasers and Electro-Optics: Laser Science to Photonic Applications, CLEO 2011

Gabbay, Alon; Reno, J.L.; Wendt, J.R.; Gin, Aaron G.; Wanke, Michael C.; Sinclair, Michael B.; Shaner, Eric A.; Brener, Igal

Interaction between metamaterial elements and intersubband transitions in GaAs/AlGaAs quantum wells is observed in the mid-infrared. Transmission measurements were performed through metamaterial arrays, each having a different resonance frequency. © 2011 OSA.

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Results 151–175 of 271
Results 151–175 of 271