Fiber loop ring-down spectroscopy with a long-period grating cavity.
We have successfully demonstrated cavity ring-down spectroscopy in a fiber ring with a long-period grating cavity. The cavity couples >99% of light from core to cladding, interacts with the environment surrounding the fiber, and then couples unabsorbed light back into the fiber core. This design provides a relatively large evanescent wave absorption area while maintaining a very low loss for the fiber ring. The effectiveness of this cavity as a sensitive chemical sensor is also demonstrated.
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Sean
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Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada.
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Xijia
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