| 摘要 |
In one aspect, the mean pathlength of an integrated cavity is determined using a light source S1 and two detectors D1, D2. The light from the source to the first detector is not influenced by reflectivity of the cavity, and light from the source to a second detector is influenced by reflectivity. In another aspect there are two light sources S1, S2 and two detectors. The light from the first source to the first detector and the second source to the second detector is not influenced by reflectivity of the cavity, and light from the first source to the second detector and from the second source to the first detector is influenced by reflectivity. In another aspect there are two light sources and a detector wherein light from the first source to the detector is influenced by reflectivity of the cavity and light from the second source to the detector is not influenced by reflectivity. A reference pathlength is determined during a calibration step at a first time using a calibration standard. The pathlength is determined at a second time using the reference pathlength and a comparison of the ratio of light fluxes measured at the first and second times. |
