Optical modulator using isolator and optical transmitter including the

Abstract

An optical modulator using an isolator, and an optical transmitter including the same are provided. The optical modulator modulates a carrier wave generated by an optical source according to a predetermined electrical signal. An isolator in the modulator includes a Faraday rotator in which the rotation angle of polarization is different according to the intensity of an applied magnetic field. The rotator controls isolation of an optical signal according to the polarization rotation angle and outputs a modulated optical signal. A magnetic field generator produces a magnetic field whose intensity is controlled by a predetermined electrical signal, and applies the produced magnetic field to the isolator. A signal generator supplies the electrical signal to the magnetic field generator and controls the intensity of the electrical signal. The magnetic field generator is mounted on the optical isolator, and the electric signal applied to the magnetic field generator is adjusted to control the intensity of the magnetic field formed in the isolator. Accordingly, isolation of an optical signal is activated or deactivated, thereby modulating a continuous wave optical signal. Thus, a small and cheap optical modulator having an excellent temperature property can be realized and easily housed in the transmitter.