BROAD BAND LIGHT SOURCE FOR MEASURING OPTICAL DEVICE USING FEEDBACK LOOP

摘要

PURPOSE: A broad band light source for measuring an optical device using a feedback loop is provided to raise the light intensity, to reduce the difference of a light output, and to increase the output intensity at the long wavelength band. CONSTITUTION: A seed-beam is installed in the existing optical fiber amplifier, thereby increasing the output of the long wavelength band. An EDF(erbium doped fiber)(102) is used as an amplification medium. An optical isolator(200) is located at the front end of the EDF, and an optical isolator(206) is located at the rear end of the EDF. A wavelength coupler(202,204) is used for sending a pump light emitted from a laser diode(207,208) to the EDF. An ASE(amplified spontaneous emission) generated for an amplification process of a signal light is used the seed-beam via the feedback loop. The feedback loop consists of a filter(210) for selecting a specific wavelength, a forward and reverse optical isolator(209) for preventing the beam reflow. A wavelength selection coupler(210,205) is used to emit the seed-beam and the signal light. The length of the EDF is extended using an EDF amplifier for increasing an output of a long wavelength band. An erbium ion of the EDF energized by the pump light is spontaneously emitted to produce a high output at a conventional wavelength band. By using the seed-beam in the conventional band, the wavelength is amplified, thereby increasing the maximum output.