Ultra-Wide Bandwidth and High Resolution Photonic Analog to Digital and Digital to Analog Converters

摘要：非技术：在当今技术驱动的世界中，数字电子和数字系统无处不在。他们的硬件和软件是我们每天生活中多次接触的一切事物的本质。现实生活系统产生的模拟信号需要转换成数字形式，然后才能通过数字技术进行处理。这是使用模数转换器（ADC）完成的。几乎所有现有的adc都是电子的。有许多类型的adc具有不同的分辨率和速度。随着ADC分辨率的提高，其保真度显著提高。虽然电子adc提供非常高的分辨率，但它们的运行速度不是很快。本提案旨在开发一种高速ADC光子学技术，该技术在不牺牲分辨率的情况下运行。同样的技术也被用于光纤通信系统中，人们对它很了解，而且它的部件也可以在市场上买到。但是，在演示整个ADC之前，需要开发一些特殊组件。该项目将开发和制造这些组件，并演示ADC的概念操作验证。这种高分辨率和快速的ADC将改善许多应用，如仪器仪表、雷达、光纤通信和宽带信号分配。技术：本提案介绍了一种新的光子ADC方法，该方法可以在20 GHz及更高的带宽下提供8位分辨率。所提出的基本ADC非常类似于没有光纤的波分复用（WDM）光纤数字链路。它由一个多波长源、一个量化器、一个采样器、一个解复用器和接收器组成。量化器是一个高速马赫-曾德尔调制器（MZM），它的手臂之间有意的路径长度差异。采样是在量化器之后进行的。不同波长的采样输出产生与应用于量化器的模拟信号的数字化版本相对应的代码。这一基本思想在使用子秩方法来提高比特数的同时减少了组件计数后得到了改进。这需要一个数模转换器（DAC），它可以由单个MZM制成。这种模数转换器的实际工作需要低压高速的MZM作为量化器和DAC。所需的超低抖动采样也可以使用这种MZMs进行。本提案的重点是开发这些关键组件，即量化器，DAC和采样器，并对ADC的缩小版本进行概念验证演示。

Title: Ultra-Wide Bandwidth and High Resolution Photonic Analog to Digital and Digital to Analog ConvertersAbstract:Nontechnical: In today's technology driven world digital electronics and digital systems are ubiquitous. Their hardware and software are the essence of everything that touches our lives many times a day. Real life systems generate analog signals which need to be converted into digital form before they can be handled by digital technology. This is done using an Analog to Digital Converter (ADC). Almost all the existing ADCs are electronic. There are many types of ADCs with different resolution and speed. As the resolution of an ADC increases its fidelity improves significantly. Although electronic ADCs provide very high resolution they do not operate very fast. This proposal aims to develop a high speed ADC photonics technology which operates without sacrificing resolution. The same technology is used in fiber optic communication systems, is well understood and its parts are commercially available. However, a few special components need to be developed before the entire ADC can be demonstrated. This project will develop and fabricate such components and demonstrate a proof of concept operation of the ADC. Such high resolution and fast ADC will improve many applications, such as instrumentation, radar, optical fiber communication and wide bandwidth signal distribution. Technical: This proposal introduces a new and novel approach for a photonic ADC that can deliver eight bits of resolution at bandwidths of 20 GHz and higher. The proposed basic ADC resembles very much to a wavelength division multiplexed (WDM) fiber optic digital link without the fiber. It consists of a multi wavelength source, a quantizer, a sampler, a demultiplexer and receivers. The quantizer is a high-speed Mach-Zehnder modulator (MZM) with an intentional path length difference between its arms. The sampling is done after the quantizer. The sampled outputs at different wavelengths generate a code corresponding to the digitized version of the analog signal applied to the quantizer. This basic idea is improved upon using a subranging approach to improve the number of bits while reducing the component count. This requires a digital to analog converter (DAC), which can be made out of a single MZM. The practical operation of such an ADC requires low-voltage and high-speed MZM for quantizer and DAC. The required ultra-low jitter sampling can also be performed using such MZMs. The focus of this proposal is to develop these critical components, namely the quantizer, DAC and the sampler, and make a proof of concept demonstration of a scaled down version of the ADC.