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1.
Phys Rev Lett ; 110(13): 137404, 2013 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-23581371

RESUMO

We use terahertz pulses to induce resonant transitions between the eigenstates of optically generated exciton populations in a high-quality semiconductor quantum well sample. Monitoring the excitonic photoluminescence, we observe transient quenching of the 1s exciton emission, which we attribute to the terahertz-induced 1s-to-2p excitation. Simultaneously, a pronounced enhancement of the 2s exciton emission is observed, despite the 1s-to-2s transition being dipole forbidden. A microscopic many-body theory explains the experimental observations as a Coulomb-scattering mixing of the 2s and 2p states, yielding an effective terahertz transition between the 1s and 2s populations.

2.
Opt Express ; 21(7): 8821-30, 2013 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-23571972

RESUMO

We demonstrate a fiber-based slow light system using a carbon disulfide (CS2)) filled integrated liquid-core optical fiber (i-LCOF). Using 1 meter of i-LCOF we were able to delay 18ps pulses up to 34ps; a delay of 188% of the pulse width. This experimental setup serves as a foundation for slow-light experiments in other nonlinear liquids. Numerical simulations of pulse-propagation equations confirmed the observed delay and a simplified method is presented that can be applied to calculate induced delay for non-cw Stokes pulses. The system is all-fiber and compact with delays greater than a pulse width, indicating potential application as an ultrafast controllable delay line for time division multiplexing in multiGb/s telecommunication systems.


Assuntos
Dissulfeto de Carbono/química , Tecnologia de Fibra Óptica/instrumentação , Análise Espectral Raman/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Luz , Espalhamento de Radiação , Integração de Sistemas
3.
Opt Lett ; 38(4): 543-5, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23455130

RESUMO

We report Brillouin lasing in an integrated liquid-core optical fiber filled with neat CS2. This is the first observation of Brillouin lasing in an optical fiber filled with a liquid, to the best of our knowledge. The linewidth of the single frequency liquid-based Brillouin laser was estimated to be <1 kHz by beating two similar but independent lasers against one another.

4.
Opt Express ; 20(7): 8148-54, 2012 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-22453484

RESUMO

We have developed a novel integrated platform for liquid photonics based on liquid core optical fiber (LCOF). The platform is created by fusion splicing liquid core optical fiber to standard single-mode optical fiber making it fully integrated and practical - a major challenge that has greatly hindered progress in liquid-photonic applications. As an example, we report here the realization of ultralow threshold Raman generation using an integrated CS2 filled LCOF pumped with sub-nanosecond pulses at 532 nm and 1064 nm. The measured energy threshold for the Stokes generation is 1nJ, about three orders of magnitude lower than previously reported values in the literature for hydrogen gas, a popular Raman medium. The integrated LCOF platform opens up new possibilities for ultralow power nonlinear optics such as efficient white light generation for displays, mid-IR generation, slow light generation, parametric amplification, all-optical switching and wavelength conversion using liquids that have orders of magnitude larger optical nonlinearities compared with silica glass.


Assuntos
Cristais Líquidos/química , Fibras Ópticas , Desenho de Equipamento , Análise de Falha de Equipamento , Fótons , Integração de Sistemas
5.
Opt Lett ; 37(5): 942-4, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22378446

RESUMO

We report on a new platform for all-optical switching based on inverse Raman scattering in liquids. Narrowband switching, which could be suitable for wavelength-division-multiplexed applications, is demonstrated using integrated liquid-core optical fiber infiltrated with both neat liquids (CCl(4) and CS(2)) as well as an organic chromophore (ß-carotene) dissolved in CCl(4). Compared to standard glass optical fibers, these liquids have much larger Raman loss coefficients, which help reduce the pump power by at least an order of magnitude. Further improvements can be expected with the development of highly soluble organic compounds possessing large Raman cross sections.

6.
Opt Express ; 19(13): 12532-9, 2011 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-21716494

RESUMO

We report the observation of Zeno switching through an inverse Raman scattering (IRS) process in an optical fiber. In IRS, light at the anti-Stokes frequency is strongly attenuated in the presence of a pump field, allowing it to be used for all-optical switching and modulation. Our observed level of induced absorption via IRS in the optical fiber is > 20 dB in a time scale of less than 5 ps. The full Raman response spectrum was extracted experimentally and excellent agreement was found between the experimental data and theoretical modeling of IRS.


Assuntos
Lasers , Fibras Ópticas , Análise Espectral Raman/instrumentação , Análise Espectral Raman/métodos , Desenho de Equipamento , Germânio/química , Modelos Teóricos , Processamento de Sinais Assistido por Computador/instrumentação , Dióxido de Silício/química , Telecomunicações/instrumentação
7.
Phys Rev Lett ; 101(9): 097401, 2008 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-18851657

RESUMO

It is shown that spectrally resolved photon-statistics measurements of the resonance fluorescence from realistic semiconductor quantum-dot systems allow for high contrast identification of the two-photon strong-coupling states. Using a microscopic theory, the second-rung resonance of Jaynes-Cummings ladder is analyzed and optimum excitation conditions are determined. The computed photon-statistics spectrum displays gigantic, experimentally robust resonances at the energetic positions of the second-rung emission.

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