基于微结构光纤的10 GHz超过1100信道的平坦超连续谱光源

报道了一种基于微结构光纤的宽带、平坦超连续谱(SC)光源。利用锁模半导体激光器产生的1.6ps,重复率为10GHz的光脉冲,通过一段80m的色散平坦高非线性微结构光纤(HNL-MF),在1.55μm波长区域产生了谱宽超过100nm的平坦超连续谱。实验中采用的微结构光纤的非线性系数约为11W-1·km-1。光纤具有小的正常色散和平坦的色散特性,在1550nm波长处,光纤的色散值约为-0.58ps·nm-1·km-1,而在1500～1650nm波长范围内,光纤的色散值变化小于1.5ps·nm-1·km-1。实验中获得的宽带、平坦超连续谱在1503～1593nm宽达90nm的波长范围内,具有±2.5dB的平坦度。该宽带、平坦超连续谱能同时提供波长间隔为10GHz,超过1100路的多波长载波信道。通过对光谱滤波,获得了速率为10Gbit/s的多波长脉冲序列。这样的超连续谱光源在波分复用(WDM)光通信系统、光波长变换等方面都有重要的应用。

10 GHz-Spaced over 1100 Channel Flat Supercontinuum Source Generated in a Microstructure Fiber

The generation of a flat supercontinuum (SC) spectrum of over 100 nm in the 1.55 μm region by injecting 1.6 ps, 10-GHz repetition rate optical pulses into an 80-m-long dispersion-flattened highly nonlinear microstructure fiber (HNL-MF) is demonstrated. The experimental microstructure fiber with a nonlinearity of ～11 W-1·km-1 has small normal dispersion and is characterized by flattened chromatic dispersion. The chromatic dispersion is about -0.58 ps·nm-1·km-1 at 1550 nm, and it varies less than 1.5 ps·nm-1·km-1 between 1500 and 1650 nm. The generated flat broadband supercontinuum ranging from 1503 to 1593 nm has the flatness of ±2.5 dB. This flat broadband supercontinuum can simultaneously supply more than 1100 multi-wavelength channels with 10-GHz spacing. The multi-wavelength pulse trains at 10 Gbit/s based on spectral slicing are also demonstrated. Such supercontinuum source has important applications, such as wavelength division multiplexing optical communication system and optical wavelength convertor.