EML TRANSMITTER APPLYING BAND STOP FILTER THERETO

摘要

PURPOSE: An EML(Electro-absorption Modulator Laser) transmitter applying a band stop filter thereto is provided to improve chirp characteristics and an extinction ratio when transmitting an optical signal by using an EML, thereby realizing high-quality transmission characteristics. CONSTITUTION: An EML(51) optically modulates an electric signal, loads the modulated signal on a transmission light, and transmits the light. A lens(52) converges an optical signal in order to prevent loss of the optical signal outputted from the EML(51). A lens(55) converges the optical signal upon a core part of an optical line(57). An FBG(Fiber Bragg Grating) unit(56) functions as a band stop filter to remove DC components from the optical signal. An optical isolator(53) cuts off the optical signal reversely incoming to the EML(51) by reflection of the FBG(56).