| 摘要 |
In an optical system, primarily adapted for use in light scattering diagnostics e.g. Raman, Rayleigh, laser fluorescence, an obscuration means is placed between the sample volume (or object) and a light collecting means (such as a lens or mirror) to limit the backscattered light collection passed through an aperture to a shorter length along the optical axis, thereby increasing the spatial resolution of the system. In general, the effective obscuring diameter is determined as twice the ratio of the square of the distance between the image of the aperture within the sample volume and the collection means to the distance between the collection means and the aperture, times the ratio of the aperture diameter to the desired length of sample volume. In refractive embodiments, obscuration is provided by an opaque disc adjacent a collection lens. In a second embodiment, obscuration is provided by a coaxial arrangement of independent fiber optical light pipes. In a third embodiment, Cassegrainian-type reflection optics are used.
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