Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Opt Lett ; 45(22): 6258-6261, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-33186964

RESUMO

Optical bandpass filters can be utilized to suppress parasitic broadband spectral power prior to laser amplification but are typically designed around specific frequencies or require manual adjustment, thus limiting their compatibility with highly tunable or integrated laser systems. In this Letter, we introduce a self-adaptive volume holographic filter using the dynamic two-beam coupling interaction in photorefractive BaTiO3, demonstrating -10dB suppression of amplified spontaneous emission noise surrounding a tunable 780 nm diode laser peak, with <2nm filter bandwidth and 50% power throughput. The spectral filtering is automatically centered on the lasing mode, with an estimated auto-tuning rate of 100 GHz/s under typical conditions. Furthermore, the filter suppression and bandwidth can be optimized via the two-beam coupling intensity ratio and angle, respectively, for versatile control over the self-adaptive filter characteristics.

2.
Phys Rev Lett ; 120(26): 263201, 2018 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-30004774

RESUMO

We experimentally demonstrate a shaken-lattice interferometer. Atoms are trapped in the ground Bloch state of a red-detuned optical lattice. Using a closed-loop optimization protocol based on the dcrab algorithm, we phase-modulate (shake) the lattice to transform the atom momentum state. In this way, we implement an atom beam splitter and build five interferometers of varying interrogation times T_{I}. The sensitivity of shaken-lattice interferometry is shown to scale as T_{I}^{2}, consistent with simulation (2C. A. Weidner, H. Yu, R. Kosloff, and D. Z. Anderson, Phys. Rev. A 95, 043624 (2017).PLRAAN2469-992610.1103/PhysRevA.95.043624). Finally, we show that we can measure the sign of an applied signal and optimize the interferometer in the presence of a bias signal.

3.
Rev Sci Instrum ; 87(12): 123108, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28040917

RESUMO

We describe a system for loading a single atom from a reservoir into a blue-detuned crossed vortex bottle beam trap using a dynamic 1D optical lattice. The lattice beams are frequency chirped using acousto-optic modulators, which causes the lattice to move along its axial direction and behave like an optical conveyor belt. A stationary lattice is initially loaded with approximately 6000 atoms from a reservoir, and the conveyor belt transports them 1.1 mm from the reservoir to a bottle beam trap, where a single atom is loaded via light-assisted collisions. Photon counting data confirm that an atom can be delivered and loaded into the bottle beam trap 13.1% of the time.

4.
Opt Lett ; 40(14): 3368-71, 2015 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-26176471

RESUMO

An atom-chip-based integrated optical lattice system for cold and ultracold atom applications is presented. The retroreflection optics necessary for forming the lattice are bonded directly to the atom chip, enabling a compact and robust on-chip optical lattice system. After achieving Bose-Einstein condensation in a magnetic chip trap, we load atoms directly into a vertically oriented 1D optical lattice and demonstrate Landau-Zener tunneling. The atom chip technology presented here can be readily extended to higher dimensional optical lattices.

5.
Appl Opt ; 46(32): 7868-71, 2007 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-17994137

RESUMO

A modulation-demodulation scheme substantially enhances diffusion-dominated-adaptive-interferometric sensitivity. The path length sensitivity is improved by converting a quadratic small-signal response, easily drowned in system noise, to a linear response by mixing with a strong phase modulation. This conversion also shifts low-frequency signals away from 1/f noise. Experimental results show 180 fm/ [square root]Hz displacement sensitivity for a 5 Hz signal with a few milliwatts of optical power, an improvement of 3 orders of magnitude over the unenhanced system.

6.
Opt Lett ; 30(12): 1467-9, 2005 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-16007776

RESUMO

A holographic interferometer senses vapor-induced optical path length changes in polymer or other chemically sensitive films. The interferometer is inherently sensitive to changes in chemical vapor content, self-compensates for drifts, and accommodates a large array of sensor elements. A sniff-locked-loop synchronous detection method takes advantage of the interferometer's rapid response to achieve vapor concentration sensitivity in the parts-per-billion (ppb, parts in 10(9)) range. We demonstrate, for example, 40 ppb sensitivity to ethyl alcohol using poly(N-vinyl pyrrolidone) with a measurement time of 5 s.


Assuntos
Etanol/análise , Gases/análise , Holografia/instrumentação , Interferometria/instrumentação , Microquímica/instrumentação , Transdutores , Desenho de Equipamento , Análise de Falha de Equipamento , Holografia/métodos , Interferometria/métodos , Microquímica/métodos
7.
Phys Rev Lett ; 94(9): 090405, 2005 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-15783948

RESUMO

An atom Michelson interferometer is implemented on an "atom chip." The chip uses lithographically patterned conductors and external magnetic fields to produce and guide a Bose-Einstein condensate. Splitting, reflecting, and recombining of condensate atoms are achieved by a standing-wave light field having a wave vector aligned along the atom waveguide. A differential phase shift between the two arms of the interferometer is introduced by either a magnetic-field gradient or with an initial condensate velocity. Interference contrast is still observable at 20% with an atom propagation time of 10 ms.

8.
Appl Opt ; 42(23): 4736-46, 2003 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-13678358

RESUMO

The optical feature extractor is a photorefractive ring oscillator that can identify the strongest spatiotemporal component of its input space. The theoretical sections discuss the design and performance limitations of the signal extractor. A simple model of the filter's nonlinear functioning enables the reader to go directly to the experimental section that describes the making of the filter and experimental results. The device, also called the auto-tuning filter, is 5 cm2 in size, has a 3 GHz processing bandwidth, and requires less than 5 mW of continuous optical power to operate.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...