| 摘要 |
An optical measurement system (100) produces light modulated at one or more modulation frequencies, directs the modulated light from within an internal reflection element (110) onto an interface (114) between the internal reflection element (110) and a sample (150), directs light reflected from the interface (114) onto a multi-pixel detector (140), produces electronic signals (142) corresponding to the detector pixels, analyzes the electronic signals at the modulation frequencies and/or at harmonics thereof, and extracts values of reflectivity of the sample at the interface. One or more lock-in amplifiers (160) perform the signal analysis. In some examples, one lock-in amplifier can be used for each detector pixel. Modulating the light at one or more modulation frequencies, and using the lock-in amplifiers to extract the reflectivity values can improve resistance to noise. In some examples, the reflectivity values are used in an intermediate stage during optical characterization of the sample. |
