Multimodal multiplex spectroscopy using photonic crystals

Xu, Zhaochun; Wang, Zhanglei; Sullivan, Michael E.; Brady, David J.; Foulger, Stephen H.; Adibi, Ali

doi:10.1364/oe.11.002126

Cited by 95 publications

(70 citation statements)

References 13 publications

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“…Vibrações de grupos C=C de anéis aromáticos da molécula de tanino podem ser associadas a bandas observadas entre 1655 e 1400 cm -1 . Em torno de 1340 cm -1 são observadas bandas que também podem estar associadas a vibrações de grupos C=C do anel aromático 17 . Taninos são compostos fenólicos que fazem parte dos metabó-litos secundários encontrados em plantas e são conhecidos por apresentarem ação biológica [18][19][20] .…”

Section: Resultsunclassified

Taninos hidrolisáveis em Bixa orellana L.

Lima¹,

Moreno²,

Castro³

et al. 2006

Quím. Nova

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Recebido em 6/5/05; aceito em 29/8/05; publicado na web em 8/2/06 HYDROLYZABLE TANNINS IN Bixa Orellana L. The aqueous material found in the fruits of Bixa Orellana L. was collected, dried, and characterized using several experimental techniques, namely phytochemical analysis in order to identify the biologically active constituents, Fourier transform infrared (FT-IR) spectroscopy for vibrational analysis, and X-ray powder diffraction in order to identify the presence of crystalline phases in the sample. The results showed that the aqueous material possesses high concentrations of hydrolyzable tannin. This result justifies the anti-inflammatory activity of this substance reported in other studies.Keywords: hydrolyzable tannin; Bixa Orellana; spectroscopy. INTRODUÇÃOA Bixa orellana L. (urucum) pertence à família botânica Bixaceae. Internacionalmente conhecida como annatto, é uma espécie nativa do Brasil e de outras regiões tropicais do planeta 1 . As sementes de Bixa orellana L. são largamente empregadas na medicina popular como expectorante, na forma de xarope; em decocto, são usadas para gargarejos, como laxativas, estomáticas, anti-hemorrágicas, cicatrizantes e contra dispepsia 2 . As sementes secas, em maceração ou decocção, também são usadas nos males de fígado, tuberculose, afecções do coração, problemas na pele, antipirético e antiinflamatório [3][4][5][6][7] . As sementes servem ainda como antídoto para o ácido prússico que é aplicado nos casos de envenenamento com mandioca 8 , como antídoto para o ácido cianídrico, na terapia de bronquite e queimaduras 9 . Recentemente foi relatado que as sementes também possuem ação antimicrobiana 10 . Nunes 11 detectou atividade antiinflamatória e analgésica na solução aquosa encontrada nos frutos de Bixa orellana L., através de estudo comparativo com fármacos de atividade antiinflamatória e analgésica. Parrotta 12 também relata que esta solução aquosa que envolve as sementes é usada como medicamento para tratar queimadura, disenteria, gonorréia, constipação e febre.O presente trabalho trata da caracterização do sólido obtido pela desidratação da solução aquosa encontrado no interior dos frutos de Bixa orellana L. As técnicas empregadas foram testes fitoquímicos, espectroscopia no infravermelho e difração de raios-x em policristais. PARTE EXPERIMENTAL Material vegetal e coleta do extrato estudadoOs frutos de Bixa orellana L. (3 kg) utilizados neste trabalho foram obtidos no município de São Luis/MA, no bairro do Anil, durante os meses de abril a junho de 2003. A planta foi identificada no Herbário Ático Seabra da UFMA, cuja exsicata encontra-se catalogada sob o n o 1147. Na abertura dos frutos foram coletados, com o auxílio de uma seringa, 50 mL da solução aquosa presente entre as sementes e a casca. Posteriormente, foi realizada a desidratação do mesmo por meio de um dessecador. O processo de desidratação durou uma semana e foi feita à pressão atmosférica. Testes fitoquímicosOs testes fitoquímicos para verificar a presença de taninos na solução aquosa encontrado no in...

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Section: Resultsunclassified

Taninos hidrolisáveis em Bixa orellana L.

Lima¹,

Moreno²,

Castro³

et al. 2006

Quím. Nova

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“…The spectral reconstruction process can be framed as an energy minimization problem, in which the optimal solution of the input spectrum, S, is the one that minimizes the energy E = ||I − T S|| 2 [1]. To find the optimal S, we developed a simulated annealing algorithm.…”

Section: Algorithm For Spectral Reconstructionmentioning

confidence: 99%

“…While traditional spectrometers are based on one-to-one spectral-to-spatial mapping, spectrometers can also operate on more complex spectral-to-spatial mapping [1][2][3]. In these implementations, a transmission matrix is used to store the spatial intensity profile generated by different input wavelengths.…”

Section: Introductionmentioning

confidence: 99%

“…While this approach is more complicated than the traditional grating or prism based spectrometers, it affords more flexibility in the choice of dispersive element. For instance, spectrometers based on this approach have been demonstrated using a disordered photonic crystal [1], a random scattering medium [2], and an array of Bragg fibers [3]. We recently found that a multimode optical fiber is an ideal dispersive element for this type of spectrometer because the long propagation length and the minimal loss enables high spectral resolution and good sensitivity [4].…”

Section: Introductionmentioning

confidence: 99%

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All-fiber spectrometer based on speckle pattern reconstruction

2013

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A standard multimode optical fiber can be used as a general purpose spectrometer after calibrating the wavelength dependent speckle patterns produced by interference between the guided modes of the fiber. A transmission matrix was used to store the calibration data and a robust algorithm was developed to reconstruct an arbitrary input spectrum in the presence of experimental noise. We demonstrate that a 20 meter long fiber can resolve two laser lines separated by only 8 pm. At the other extreme, we show that a 2 centimeter long fiber can measure a broadband continuous spectrum generated from a supercontinuum source. We investigate the effect of the fiber geometry on the spectral resolution and bandwidth, and also discuss the additional limitation on the bandwidth imposed by speckle contrast reduction when measuring dense spectra. Finally, we demonstrate a method to reduce the spectrum reconstruction error and increase the bandwidth by separately imaging the speckle patterns of orthogonal polarizations. The multimode fiber spectrometer is compact, lightweight, low cost, and provides high resolution with low loss.

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“…Matrix left-inversion gives a least-square solution s ¼ L À 1 W, which applies in situations even when W = 2 spanfu i g i where u i are the calibrated frequencies, that is, the spectral reconstruction works even for a continuous input spectrum. In addition, this solution can be treated as an initial solution s 0 to the more general minimization problem kLs À Wk 2 where || Á || 2 denotes the 2-norm [19][20][21][22][23]29 . By eliminating the non-physical negative solutions and then solving this minimization problem using a nonlinear optimization algorithm, we can reconstruct the spectra of a measured signal more accurately (see Supplementary Methods for further discussion).…”

Section: Resultsmentioning

confidence: 99%

High-resolution optical spectroscopy using multimode interference in a compact tapered fibre

et al. 2015

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Optical spectroscopy is a fundamental tool in numerous areas of science and technology. Much effort has focused on miniaturizing spectrometers, but thus far at the cost of spectral resolution and broad operating range. Here we describe a compact spectrometer that achieves both high spectral resolution and broad bandwidth. The device relies on imaging multimode interference from leaky modes along a multimode tapered optical fibre, resulting in spectrally distinguishable spatial patterns over a wide range of wavelengths from 500 to 1,600 nm. This tapered fibre multimode interference spectrometer achieves a spectral resolution down to 40 pm in the visible spectrum and 10 pm in the near-infrared spectrum (corresponding to resolving powers of 10 4 -10 5 ). Multimode interference spectroscopy is suitable in a variety of device geometries, including planar waveguides in a broad range of transparent materials.

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Multimodal multiplex spectroscopy using photonic crystals

Cited by 95 publications

References 13 publications

Taninos hidrolisáveis em Bixa orellana L.

Taninos hidrolisáveis em Bixa orellana L.

All-fiber spectrometer based on speckle pattern reconstruction

High-resolution optical spectroscopy using multimode interference in a compact tapered fibre

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