Apparatus and method for measuring optical signals by optical sampling

摘要

A measurement apparatus (10) for an optical signal under test includes a closed-loop optical path (20), an optical mixer (50) in the closed-loop optical path (20) and a photodctcctor (70). The optical signal under test and sampling light having a wavelength different from that of the optical signal under test are circulated in the closed-loop optical path (20). Sum/difference frequency light is generated every time the sampling light passes through the optical mixer (50). The sum/difference frequency light is detected by the photodetector (70), which provides a signal representative of the waveform of the optical signal under test.