RESUMO
A new fiberized fluorescence imaging probe is presented. This device can potentially be used for a wide range of biological or medical applications. By exploiting the chromatic aberrations of gradient index lenses, the excitation blue or near-UV excitation light is focused on the sample surface, while the red fluorescence signal is efficiently launched back to collecting fibers. The excitation fiber is single mode at the working wavelength so that a resolution of 5 microm is obtained over a scanning area of several square millimeters. Experimental fluorescence images are presented. They concern either self-fabricated fluorescent microsamples or views of leaves that constitute an example of biological tissues analysis. The probe can also be adapted for spectroscopic investigations.
Assuntos
Tecnologia de Fibra Óptica/instrumentação , Aumento da Imagem/instrumentação , Microscopia Confocal/instrumentação , Microscopia de Fluorescência/instrumentação , Folhas de Planta/citologia , Transdutores , Desenho de Equipamento , Análise de Falha de Equipamento , Aumento da Imagem/métodos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
A 1540-nm external-cavity laser diode with an intracavity electro-optic wavelength tuner is demonstrated. Coarse- and fine-wavelength tuning is achieved with a single lithium niobate wavelength tuner. One section of the crystal is used as a tunable-wavelength filter to tune the wavelength by mode hopping. The other operates as a phase modulator to change the optical length of the cavity and to tune the wavelength continuously. Coarse tuning by mode hopping is obtained over a range of 5.3 nm with a tuning rate of 580 MHz/V. Continuous tuning is obtained over 82% of the free spectral range of the cavity. The wavelength switching time is 10 ns for the cavity used.
