Novel lightsources with variable frequency, waveform, and number of channels for communications and sensings.

该项目的目的是开发具有频率、波形和通道数量可控性的光源。本课题取得的成果如下：利用基于半导体放大器的波形/波长转换器，实现了脉宽在10ps~90ps之间变化的16路多波长光源。所产生的光信号被成功地应用于色散值在-100ps/nm到460ps/nm之间的光纤上的传输，从而通过调整脉冲宽度来最小化接收信号的功率损失。脉冲宽度优化的信号也优于传统使用的光信号格式。成功地实现了光谱平坦度在5 nm以内的多波长输出，并利用半导体光放大器进行波长转换，实现了1460~1610 nm波长范围内的可变波长光时钟。成功地获得了10 GHz的时钟信号，具有很高的光信噪比，实现了外光注入控制的窄线宽单偏振单频光纤激光器。通过适当调节激光功率和外加光功率，实现了1545~1560 nm的低漂移波长调谐。利用较短脉冲宽度的种子脉冲对基于光纤喇曼孤子效应产生超连续谱的多波长光源进行了改进。采用1.3ps脉宽的种子光源，获得了较大的带宽和较好的光谱平坦度。对产生的光谱的详细描述仍在进行中。

The purpose of the project is to develop lightsources with controllabilities of their frequencies, waveforms, and number of channels. The achievements of this project are as follows.With the use of semiconductor-amplifier based waveform/wavelength converter, a 16-channel multi-wavelength light-source with variable pulsewidth between 10ps and 90ps were demonstrated. The generated optical signals were successfully applied to transmission over fibers with various dispersion values between - 100ps/nm and 460ps/nm so that the power penalties of received signals were minimized by adjusting the pulsewidths. Pulsewidth optimized signal was also found to be superior to conventionally used optical signal formats.A multi-wavelength fiber laser with an intra-cavity phase modulation was demonstrated. Multi-wavelength output with a good spectral flatness within 5nm was successfully demonstrated.Wavelength conversion with a semiconductor optical amplifier was applied to realize a variable wavelength optical clock in the wavelength range between 1460nm and 1610nm. 10GHz clock signal was successfully obtained with a very high optical signal to noise ratio.Narrow-linewidth single-polarization single-frequency fiber laser controlled by an external light injection was demonstrated. With a proper adjustment of lasing and external light powers, low-drift wavelength tunable operation between 1545nm and 1560nm was achieved.Improvement of multi-wavelength lightsource based on supercontinuum spectrum generation through Raman soliton effect in optical fiber was investigated with the use of seed pulses with shorter pulsewidth. With the use of 1.3ps pulsewidth seed light source, larger bandwidth and better flatness of the generated spectrum was obtained. Detailed characterization of the generated spectrum is still in progress.