C波段可调谐单频光纤激光器的研究

发布时间：2018-05-06 02:06

本文选题：可调谐 + 单频　；参考：《华南理工大学》2015年硕士论文

【摘要】：超高速(400G/1T)相干光通信网络由于需要更高的传输速率和更为复杂的载波调制格式,而对激光光源模块有更高的要求——线宽窄(100 k Hz)、信噪比高(40 d B)以及具有波长可调谐功能。相比于半导体单频激光器,单频光纤激光器的线宽更窄、信噪比更高、与光纤元件兼容,有潜力成为超高速相干通信的理想应用光源。本论文对可调谐单频光纤激光器进行了深入的实验研究。构造了满足ITU-T建议的C波段信道波长输出的可调谐单频光纤激光器。本文具体工作内容和取得成果如下:首先,提出了可调谐单频激光器的总体设计方案。其具体实现方案包括1)通过控制不同泵浦芯片开关实现不同激射波长的单频激光输出,使光纤激光器实现输出波长粗调的方案。2)使用高增益的磷酸盐光纤作为激光增益介质,缩短谐振腔长,从而使光纤激光器实现单频激光输出特性的方案。3)使用精密温度控制实现单频光纤激光器输出波长精确可调的方案。其次,针对ITU-T建议C波段信道的应用,构建了四个激射不同波长的光纤激光谐振腔,组成可调谐单频光纤激光器,并对其不同输出波长的激光特性开展实验研究。实验测得不同波长的激光均能满足边模抑制比(SMSR)大于65 d B,功率大于14 m W,相对强度噪声(RIN)低于-135 d B/Hz,线宽小于3 k Hz,偏振消光比(PER)大于21 d B,而且都有良好的单频输出特性。同时为了实现对激光器输出波长的精确调谐,分别通过温度控制和压电陶瓷(PZT)拉伸窄带光纤光栅的方式,对单频光纤激光器波长调谐特性进行了实验研究。最后,为了提高可调谐单频激光器的输出功率,对其输出1535 nm和1550 nm波长的单频激光进行基于铒镱共掺磷酸盐光纤的放大研究。通过实验得到了增益光纤最佳使用长度4 cm。经功率放大后其输出激光功率大于20 m W,边模抑制比大于60 d B,并保留了窄线宽(k Hz量级线宽)单频光纤激光的优势。该可调谐单频光纤激光器具有紧凑的结构,更低的成本,优异的性能,有望应用到下一代相干光通信网络中。
[Abstract]:Because of the need of higher transmission rate and more complex carrier modulation format, the ultra-high speed (400G / 1 T) coherent optical communication network has higher requirements for the laser light source module (100kHz) with a high signal-to-noise ratio (SNR) of 40dB) and wavelength tunable. Compared with semiconductor single-frequency lasers, single-frequency fiber lasers have narrower linewidth and higher signal-to-noise ratio (SNR), which are compatible with fiber components and have the potential to be an ideal light source for ultra-high speed coherent communication. In this paper, the tunable single-frequency fiber laser is studied experimentally. A tunable single-frequency fiber laser satisfying ITU-T 's recommendation for C-band channel wavelength output is constructed. The main contents and achievements are as follows: firstly, the overall design scheme of tunable single frequency laser is proposed. The scheme includes: 1) using high gain phosphate fiber as laser gain medium to realize single frequency laser output with different pumping wavelength by controlling different pump chip switch, and making fiber laser realize output wavelength coarse tuning. The scheme of reducing the length of resonator so that the fiber laser can realize the output characteristic of single frequency laser. 3) using precise temperature control to realize the precise tunable wavelength of single frequency fiber laser. Secondly, four fiber laser resonators with different laser wavelengths are constructed to form tunable single-frequency fiber lasers for the application of C-band channels recommended by ITU-T, and the laser characteristics of different output wavelengths are studied experimentally. The experimental results show that the laser with different wavelengths can satisfy the side mode rejection ratio (SMSRR) greater than 65 dB, the power more than 14 MW, the relative intensity noise (RIN) less than -135 dB / Hz, the linewidth less than 3 kHz, and the polarization extinction ratio (per) > 21 dB, and all of them have good single-frequency output characteristics. At the same time, in order to realize the accurate tuning of the output wavelength of the laser, the wavelength tuning characteristics of the single-frequency fiber laser are studied experimentally by temperature control and PZT-based stretching of narrow-band fiber grating. Finally, in order to improve the output power of tunable single-frequency laser, the amplification of single-frequency laser with output wavelength of 1535 nm and 1550 nm is studied based on erbium-ytterbium co-doped phosphate fiber. The optimum operating length of the gain fiber is 4 cm. After power amplification, the output laser power is more than 20 MW, the edge-mode rejection ratio is more than 60 dB, and the advantages of narrow linewidth (k Hz) single frequency fiber laser are retained. The tunable single-frequency fiber laser with compact structure, lower cost and excellent performance is expected to be used in the next generation coherent optical communication network.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248

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