A FIBER LASER USING DISPERSION IMBALANCED NONLINEAR LOOP MIRRORS

• Main Authors: LEE, HAK-KYU, JEON, MIN-YONG, LIM, DONG-SUNG, LEE, EL-HANG, KIM, HO-YOUNG
• Format: Patent
• Language: English; Korean
• Published: 01.07.2000
• Edition: 7
• Subjects: OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS

PURPOSE: An optical fiber laser using a dispersion imbalanced nonlinear amplifying loop mirror is provided which includes two optical fibers having different dispersion values in a nonlinear loop on the basis of the conventional Erbium-doped '8'-shaped optical fiber laser and induces passive mode locking, to generate short-length pulses. CONSTITUTION: An optical fiber laser using a nonlinear loop mirror is constructed of a nonlinear loop mirror(1) and a linear loop(2). The nonlinear loop mirror includes the first optical fiber(41) whose dispersion constant value corresponds to the minimum value of the wavelengths of the laser, the second optical fiber(42) having a dispersion constant value larger than the dispersion value of the first optical fiber, and the first and second polarization controllers(21,22) for controlling the polarization states of signals transmitted through the first and second optical fibers, respectively. The linear loop includes an optical isolator(31) for maintaining one-way oscillation of the laser and blocking continuous waves reflected from the nonlinear loop mirror, a polarization controller(23) for the polarization of an optical pulse whose continuous waves are blocked by the optical isolator, and an amplification medium optical fiber(43) for amplifying the optical pulse with a predetermined amplification medium. The linear loop further has a wavelength division optical fiber coupler(12) for multiplexing the wavelength of the optical pulse amplified by the optical fiber, a 980nm laser diode(51) for pumping the optical signal multiplexed by the coupler, and a 90:10 optical fiber(13) directional coupler for outputting laser of 10% of the pumped optical signal. 본 발명은 기존의 어븀이 첨가한 "8" 자 형 광섬유 레이저에 있어서, 비선형 루프 내에 분산 상수값이 다른 두개의 광섬유을 구성하여 수동형 모드 로킹을 유발한 후, 짧은 펄스 길이를 생성하는 광섬유 레이저에 관한것으로, 기존의 광섬유 레이저에서는 비선형 광학 루프 거울(Nonlinear optical loop mirror : NOLM)이나 비선형 증폭 루프거울(Nonlinear amplifying loop mirror : NALM)를 사용하여 모드 로킹을 유발하나, 본 발명에서는 분산 값이 다른 두개의 광섬유로 만든 비대칭 분산 비선형 루프(Dispersion imbalanced nonlinear loop mirror: DINLM)를 도입하여, 연속파 레이저로부터 모드-로킹 된 펄스 레이저에서 솔리톤 펄스 레이저까지 레이저 발진이 가능하다.