MODE LOCKING OPTICAL FIBER LASER OSCILLATING APPARATUS

摘要

PURPOSE: A mode locking optical fiber laser oscillating apparatus is provided to stabilize a laser oscillator on a real time basis by stabilizing a length of an optical fiber laser oscillator by feeding a frequency change as an error signal back to the laser oscillator by using the fact that a frequency transition value of a Brillouin signal is sensitive to a temperature. CONSTITUTION: A Brillouin pump(101) generates a Brillouin pump signal to generate a Brillouin signal. A single mode optical fiber(102) generates a Brilliouin stimulated scattering. A directional first optical fiber coupler(103) inserts the Brillouin pump signal into an oscillator. An optical circulator(104) outputs a returning Brillouin signal. A semiconductor laser(112) serves as an excitation pump optical source for an optical pump to an erbium addition optical fiber(111) for a mode locking optical fiber laser oscillation. The second optical fiber coupler(113) couples optical signals. A function generator(114) generates a signal. An optical modulator(115) makes an active mode locking through a signal inputted from the external function generator(114). The third optical fiber coupler(116) monitors a mode locked laser output. An optical isolator(117) proceeds an optical signal in one direction. An optical fiber PZT(121) is electrically and variably shrunken and expanded to stabilize a length of the oscillator. An optical receiver(122) receives the Brillouin signal. A frequency comparator(123) compares the Brillouin signal detected from the optical receiver(122) and the frequency of the signal generated from the function generator(114). A frequency-voltage converter(124) converts the signal output from the frequency comparator(123) into an electric signal. An electric amplifier(125) amplifies the electric signal converted by the frequency-voltage converter(124).