摘要
在连续光全光纤光学参量振荡器(FOPO)中,目前主要利用可调滤波器(TBPF)等高插入损耗的滤波器件进行边带光输出波长的调谐,这种方式所引起的高环形腔损耗限制了FOPO输出性能的进一步提升。为解决此问题,提出了基于多模干涉(MMI)滤波器的低腔损耗可调谐连续光FOPO。通过选取不同长度和纤芯尺寸的多模光纤制作级联单模-多模-单模光纤(SMS)作为滤波器件,使其在选定波长处的插入损耗小于1 dB,FOPO环形腔的总损耗不大于5 dB,并通过对SMS器件施加轴向拉力的方式调节滤波器件的透射谱,实现了1 494~1 501 nm和1 638~1 629 nm范围内的双边带可调谐连续光输出。
High insertion loss filter components like tunable bandpass filters(TBPF) are commonly used to tune the sideband output wavelengths in continuous-wave(CW) all-fiber optical parametric oscillators(FOPO). Aiming at reducing the high ring-cavity loss mainly caused by the insertion-loss of the bandpass filter, a low cavity-loss tunable CW FOPO based on multimode interference(MMI) filter was proposed.Cascaded single-mode-multimode-single-mode(SMS) fiber devices were fabricated as filter devices by selecting multimode fibers with different lengths and core-sizes. And their insertion-losses at selected wavelengths were less than 1 dB, and the total losses of the FOPO ring cavity were not more than 5 dB.By applying an axial pulling force to the SMS device to adjust the transmission spectrum of the filter device, the double-sideband output wavelengths could be tunable in the range of 1 494-1 501 nm and1 638-1 629 nm.
引文
[1] Shi Wei, Fu Shijie, Fang Qiang, et al. Single-frequency fiber laser based on rare-earth-doped silica fiber[J]. Infrared and Laser Engineering, 2016, 45(10):1003001.(in Chinese)史伟,付士杰,房强,等.基于稀土掺杂石英光纤的单频光纤激光器[J].红外与激光工程, 2016, 45(10):1003001.
[2] Shi Wei, Fang Qiang, Li Jinhui, et al. High-performance fiber lasers for LIDARs[J]. Infrared and Laser Engineering, 2017, 46(8):0802001.(in Chinese)史伟,房强,李锦辉,等.激光雷达用高性能光纤激光器[J].红外与激光工程, 2017, 46(8):0802001.
[3] Huang D, Swanson E A, Lin C P, et al. Optical coherence tomography[J]. Science, 1991, 254(5035):1178-1181.
[4] Hu C R, Slipchenko M N, Wang P, et al. Stimulated Raman scattering imaging by continuous-wave laser excitation[J].Optics Letters, 2013, 38(9):1479-1481.
[5] Marhic M E, Wong K K, Kazovsky L G, et al. Continuouswave fiber optical parametric oscillator[J]. Optics Letters,2002, 27(16):1439-1441.
[6] Luo Z, Zhong W D, Tang M, et al. Fiber-optic parametric amplifier and oscillator based on intracavity parametric pump technique[J]. Optics Letters, 2009, 34(2):214-216.
[7] Yang S, Xu X, Wong K K Y. Low threshold dual-cavity continuous-wave fiber optical parametric oscillator[C]//OptoElectronics and Communications Conference. IEEE,2009:1-2.
[8] Malik R, Marhic M E. High-power continuous-wave operation of a fiber optical parametric oscillator in L and U bands[J]. Optical Fiber Technology, 2014, 20(6):694-701.
[9] Mohammed W S, Smith P W, Gu X. All-fiber multimode interference bandpass filter[J]. Optics Letters, 2006, 31(17):2547-2549.
[10] Mohammed W S, Mehta A, Johnson E G. Wavelength tunable fiber lens based on multimode interference[J].Journal of Lightwave Technology, 2004, 22(2):469-477.
[11] Tripathi S M, Kumar A, Varshney R K, et al. Strain and temperature sensing characteristics of single-Mode-multimodesingle-mode structures[J]. Journal of Lightwave Technology, 2009, 27(13):2348-2356.
[12] Huang S Y, Blake J N, Kim B Y. Perturbation effects on mode propagation in highly elliptical core two-mode fibers[J]. Journal of Lightwave Technology, 1990, 8(1):23-33.