Real-time optical spectrum analysis of a light source using a polarimeter.

Optical spectrum analysis and polarization analysis are not generally related by conventional wisdom. In this paper, we show that the spectrum of a light beam can be obtained using a polarimeter, with a resolution and a speed that cannot be achieved with traditional spectrum analysis methods. We experimentally demonstrate a novel polarimeter-based optical spectrum analyzer (P-OSA) and show that the high-speed and high-resolution nature of the device enables rapid measurement of the spectrum of swept laser sources at a repetition rate of more than 100 kHz. We show the generation of a unique 3-D plot of the spectral shape of a light source as its center wavelength is swept.