Spectral manipulation and tunable optical frequency ruler using liquid crystal’s birefringence

Abstract

The polarization control method using a birefringent solid crystal produces only fixed optical frequency rulers and complementary spectra. A configuration using liquid crystal (LC) improves and extends above method’s ability to control incident polychromatic light spectra. It is shown that, by adjusting the voltage applied to the LC module, the induced birefringence and phase shift can be controlled in a wide range; consequently, this scheme can be employed to realize tunable optical frequency ruler, spectral switches, and spectrum compression. Compared with the previous one, this work provides an easier, and more powerful way to manipulate polychromatic light, which benefits its future applications, such as optics communication, spectra control, etc.