CAREER: Optical-frequency electronics for measuring the fields of light guided on chips

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

As light travels it creates oscillating electric and magnetic fields. These field oscillations are challenging to measure in time due to how quickly they fluctuate (e.g. visible light fields oscillate hundreds of trillions of times per second). In this work we will develop nanometer-scale antennas (one nanometer is one billionth of one meter) capable of capturing the fields of light inside optical waveguides, small glass channels for transporting light on a chip, as they oscillate in time. These waveguide-integrated antennas will be capable of measuring electric fields with a time resolution of less than one femtosecond (one millionth of one billionth of one second). Our work will provide researchers and engineers with full access to the information stored within the fields of light. This access could enable new technologies for enhanced optical sensing, or new forms of optical frequency electronics for high-speed computing and communications. Beyond the technical efforts of this program, we will pursue outreach and education efforts that span from local to global. We will develop interactive course materials based around executable textbook platforms that will be openly available to the public. We will actively contribute our expertise to public knowledge repositories such as Wikipedia. We will use publicly available services to host free and open copies of our manuscripts, data, and code before publication in academic journals. Finally, we will work with K-12 schools in rural Appalachia, where the PI is from, to deliver a series of hands-on workshops and seminars. These workshops and seminars will connect students there with our research, as well as science, technology and mathematics education more broadly. We will target school districts with some of the lowest college completion rates in the country (as low as 5% in some counties). Our efforts will help cultivate a more inclusive and vibrant research community for future generations. Chip-integrated frequency comb sources are developing rapidly. To leverage the reduction in size, cost, and complexity that these sources offer, compact, scalable, and ultrafast field-sensitive optical detectors are needed. We will develop waveguide-integrated petahertz-electronic devices that will enable all-on-chip few-cycle waveform control and field-resolved metrology. First, we will design, fabricate, and test waveguide-integrated nanoantenna-based detectors for the detection and stabilization of carrier-envelope phase (CEP). These detectors will deliver CEP-sensitive signal to noise ratios on the order of tens of dB at tens to hundreds of kilohertz resolution bandwidths, and we will demonstrate their ability to stabilize few-cycle frequency combs. Unlike f-2f techniques, the methods explored here will circumvent the need for nonlinear conversion and will be coupled to standard waveguide materials such as silicon nitride just tens of microns in length. Second, we will develop waveguide-integrated nanoantenna detectors for field-resolved sampling of arbitrary optical waveform. We will use these field-sampling devices to demonstrate label-free molecular detection, and to sample nonlinear light-matter interaction dynamics. We will study how to leverage optimized device designs, signal readout multiplexing, waveguide coupling, and excitation methods to achieve few- to single-shot waveform and CEP detection. Applications will be far-reaching. The devices developed in this program will enable studies of linear and nonlinear light-matter interaction dynamics in complex media, such as exciton dynamics important to solar energy conversion or electron dynamics that result in extreme nonlinearities. Applications include label-free molecular detection, and the stabilization of on-chip frequency combs for atomic clocks or ranging instruments. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.