| 摘要 |
PURPOSE:To cut down circuit scale and to superimpose an auxiliary signal on a main signal by applying auxiliary signal voltage to a primary electric optical element so as to modulate the phase of a laser beam. CONSTITUTION:An intensity-modulated laser beam from a semiconductor laser 10 is convered into parallel light by a first lens 11 and the phase is modulated through a polarizer 12 according to the auxiliary signal from an auxiliary signal voltage source 14 by a primary electron optical element 13 wherein the changes of refractive indexes of two kinds of light waves by double refraction can be obtained to the change of a low frequency electric field. The outgoing light of this element 13 is condensed with the second lens 13 and is emitted through an optical fiber 16. Hereby, there is no necessity of providing an electric circuit to superimpose an auxiliary signal at the outside, and the scale of circuit can be cut down and the auxiliary signal can be superimposed on the main signal. |
