Ultrahigh-speed and ultrawide-band information processing chips and optical computing systems demand an all-optical logic data distributor. Such a distributor should have the capacity to distribute an input light signal to an arbitrary output waveguide and should be based on an all-optical tunable directional coupling of light in a waveguide array based on third-order nonlinear optical effects. Unfortunately, most of the previous works done in this field have shown that the intensity contrast ratio between the output logic states “1” and “0” is lower than 11 dB for all-optical logic data-distributors. Despite good progress being reported, it still remains challenging to realize ultralow-power and ultrafast all-optical data distributors with a high intensity contrast ratio between output logic states “1” and “0” owing to the intrinsic bottleneck limitations of nonlinear optical materials.
Peking University researchers: Dr. Feifan Wang, Professor Xiaoyong Hu, Dr. Hanfa Song, Dr. Chong Li, Professor Hong Yang, and Professor Qihuang Gong developed a novel method of resonant excitation via upconversion radiative-transfer to enhance the third-order nonlinearity of a nanocomposite material, composed of upconversion nanoparticles dispersed in a conjugated polymer matrix. They came up with a simple, and yet efficient strategy for realizing ultralow-power all-optical logic data-distributors with dual address bits. Their work is now published in the research journal, Advanced Optical Materials.
The research team commenced their experimental work by constructing an all-optical data distributor from three silicon slot ring resonators, which were side coupled to silicon slot waveguides and coated with a nonlinear nanocomposite. The researchers then performed 3D simulations using commercial software so as to optimize the ring resonator. They then selected the boundary mode condition and calculated its input using boundary mode analysis.
The authors of this paper observed that the large nonlinearity enhancement occurring in the nanocomposite material through resonant excitation via an upconversion radiative-transfer process, ensured an ultralow operating threshold control intensity of 10 kW cm−2. They also noted that the intensity contrast ratio between the output logic states “1” and “0” was larger than 20 decibels, which was a fivefold increase compared with previous reports.
The study has presented the realization of an ultralow-power all-optical logic data-distributor with dual address bits having three silicon slot ring resonators side-coupled to silicon slot waveguides, coated with a nonlinear nanocomposite cover layer. More so, the research team has been able to achieve an ultralow operating threshold control intensity, and high intensity contrast ratio of over 20 dB between the output logic states “1” and “0”. Such characteristics indicate good potential for building high-performance data processors. Moreover, the development of this data distributor, which enables exchange of information between different modules, is a landmark breakthrough for realization of real-time multibit all-optical computing chips. This work also paves a way to surmounting the intrinsic bottleneck limitations of nonlinear optical materials.
Feifan Wang, Xiaoyong Hu, Hanfa Song, Chong Li, Hong Yang, Qihuang Gong. Ultralow-Power All-Optical Logic Data Distributor Based on Resonant Excitation Enhanced Nonlinearity by Upconversion Radiative Transfer. Adv. Optical Mater. 2017, 5, 1700360.
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