Spectral analysis with evanescent field excitation

摘要

An apparatus includes an optical fiber and a light collection device. The optical fiber has an untapered segment and a down-tapered segment. The light collection device has an optical aperture that collects light emitted by a sample in response to the sample being located outside and adjacent a lateral surface of the down-tapered segment. The optical aperture blocks light emitted from ends of the optical fiber.