Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA.
Opt Lett. 2012 Feb 15;37(4):551-3. doi: 10.1364/OL.37.000551.
We propose and experimentally demonstrate ultrawideband monocycle pulse generation using nondegenerate two-photon absorption in a silicon waveguide. The free-carrier absorption induced pulse tail at the rising edge of inverted probe pulse is largely compensated by the overlapped pump pulse and results in a symmetric negative monocycle pulse. A 143 ps Gaussian monocycle pulse is successfully obtained with a 131.7% fractional 10 dB bandwidth using a 68 ps pulsed pump. The 10 dB bandwidth and center frequency of the RF spectrum for the generated monocycle pulse can be largely tuned using an optical delay line. An operational bandwidth of 30 nm is demonstrated experimentally with stable performance, and larger optical bandwidth is expected.
我们提出并实验演示了使用硅波导中的非简并双光子吸收产生超宽带单周期脉冲。反转探测脉冲上升沿的自由载流子吸收引起的脉冲拖尾被重叠的泵浦脉冲大大补偿，从而产生对称的负单周期脉冲。使用 68 ps 脉冲泵，成功获得了 143 ps 的高斯单周期脉冲，其 10 dB 带宽的分数为 131.7%。使用光延迟线可以大大调整所产生的单周期脉冲的 RF 光谱的 10 dB 带宽和中心频率。实验证明具有稳定性能的工作带宽为 30nm，并且预计会有更大的光带宽。
