METHOD AND A DEVICE FOR SPATIALLY-RESOLVED MEASUREMENT OF A PHYSICAL SIZE, WHICH IMPLEMENT RAPID AND/OR LOW-NOISE MEASUREMENT

摘要

PURPOSE: A method and a device for spatially-resolved measurement of a physical size are provided to rapidly measure the amplitude and phase of an optical signal with reduced noise by employing a digital filter instead of an analogue filter.;CONSTITUTION: A method for spatially-resolved measurement of a physical size is as follows. A first electric signal(6) having a first frequency that varies according to time is generated. A second electric signal(7) having a second frequency that varies according to time and is different from the first frequency is generated. An optical signal is generated and converted into the first frequency. The optical signal is changed by the interaction with an object. The changed optical signal is converted into one or more electric signals(10). The electric signals are mixed with the second signal. The mixed signal(12) is digitalized. A physical size to be measured is determined through spatial resolution based on the digitalized data. A third electric signal(8) having a third frequency equal to or several times as large as the difference between the first and second frequencies is generated. The mixed signal is sampled into the third frequency for digitalization.;COPYRIGHT KIPO 2012