Bistable random momentum transfer in a linear on- chip resonator

• 成果类型: Article
• 署名作者: Gu, Tingyi; Chang, Lorry; Wu, Jiagui; Wu, Lijun; Lee, Hwaseob; Chen, Young-Kai; Rahim, Masudur; Dong, Po; Wong, Chee Wei
• 署名单位: University of Delaware; Columbia University; University of California System; University of California Los Angeles; United States Department of Energy (DOE); Brookhaven National Laboratory
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10772
• DOI: 10.1073/pnas.2502921122
• 发表日期: 2025-07-22
• 关键词: random bit generation; chaos; laser

摘要

Optical switches and bifurcation rely on the nonlinear response of materials. Here, we demonstrate linear temporal bifurcation responses in a passive multimode microresonator, with strongly coupled chaotic and whispering gallery modes (WGMs). In micro-disks, the chaotic modes exhibit broadband transfer within the deformed cavities, but their transient response is less explored and yields a random output of the analog signal distributed uniformly from 0 to 1. Here, we build chaotic states by perturbing the multimode microring resonators with densely packed silicon nanocrystals on the wave-guide surface. In vivo measurements reveal random and digitized output that ONLY populates around 0 and 1 intensity levels. The bus waveguide mode couples first to chaotic modes, then either dissipates or tunnels into stable WGMs. This binary pathway generates high-contrast, digitized outputs. The fully passive device enables real-time conversion of periodic clock signals into binary outputs with contrasts exceeding 12.3 dB, data rates of up to 107 bits per second, and 20 dB dynamic range. Significance We consider this work to be crosscutting and fit into the journal's scope for both its scientific significance and impacts on the applications, as this work is 1) an implementation of chaotic modes in the microcavity through nanostructures (high refractive index nanocrystal) rather than macroscopic deformation; 2) explores the time domain response in microresonator supporting chaotic modes, especially with integrated photonic platform rather than the suspended structure of microdisk; 3) reports of bistable output in a linear chaotic system; and 4) uses fully passive/ powerless on-chip structures for the generation of a random bits sequence on the fly, which typically requires power-consuming electronic components, especially digital-analog conversion.