Alexander Dikopoltsev

This PhD position at ETH Zürich focuses on exploring novel regimes of frequency comb physics, specifically investigating the coherence in coupled frequency comb lasers. Frequency combs are laser sources that generate thousands of evenly spaced spectral lines, serving as ultra-precise rulers for measuring light. The group aims to realize these combs directly on chip, leveraging liquid-like light and synthetic frequency dimensions to achieve unprecedented stability and control. The project has significant implications for optical communications, precision spectroscopy, and LIDAR, as compact combs can revolutionize these fields. The research will address the challenge of combining multiple comb sources into a single coherent system, overcoming fabrication-induced detuning of the repetition rate and carrier-envelope offset. Key objectives include exploring mutual coherence between fast-gain ring lasers, creating platforms for coupled comb ladders, applying topological coupling concepts to connect detuned frequency ladders, and inducing phase locking across devices. The project will also study the interplay of nonlinear dynamics, symmetry, and disorder in coupled comb arrays. The first milestone is to demonstrate phase-coherent coupling between two controllable mid-infrared comb lasers, potentially enabling arrays of mutually coherent combs. The successful candidate will join a research environment at the intersection of fundamental physics and advanced photonics, with access to state-of-the-art cleanroom and laser laboratories at ETH Zürich. ETH Zürich is renowned for its commitment to diversity, sustainability, and excellence in science and technology. Applicants should have a strong background in physics (optics, condensed matter, or quantum electronics) and an interest in nonlinear and topological photonics, laser dynamics, or frequency metrology. Previous experience with lasers or nanofabrication is helpful but not required. Applications must be submitted online, including a cover letter, CV, academic transcripts, three reference contacts, and a publication or thesis sample. For questions about the position, contact Mr Alexander Dikopoltsev at [email protected].

This PhD position at ETH Zürich focuses on the study of frequency lattices and RF-controlled comb dynamics in fast-gain lasers. The research group is pioneering new methods for generating and controlling frequency combs—laser sources that produce many precisely tuned optical lines, which serve as rulers for light. Unlike conventional combs that rely on passive mode-locking, this project leverages resonant radio-frequency (RF) modulation to create synthetic frequency lattices, enabling rapid proliferation of comb lines and novel regimes of spectral control. The project combines advanced numerical modeling with laboratory demonstrations to investigate the physics of synthetic frequency lattices in fast-gain lasers. Key research activities include developing simulation frameworks to map the interplay of RF modulation, gain recovery, and nonlinear dynamics; studying ballistic versus diffusive transport of light in synthetic lattices and connecting these phenomena to quantum walk physics; and exploring how lattice engineering—such as periodicity, disorder, and synthetic gauge fields—affects comb bandwidth, stability, and tunability. Experimental validation will be performed using mid-infrared quantum cascade lasers, with direct feedback between modeling and laboratory work. The ideal candidate will have a background in physics, photonics, or electrical engineering, and be interested in both theoretical and experimental research. Experience with numerical simulations (e.g., time-domain propagation, coupled-mode theory, or nonlinear ODE/PDE solvers), hands-on laboratory work with lasers and photonic devices, and skills in Python-based data acquisition and analysis are highly valued. The position offers a unique environment at ETH Zürich, combining theory, computation, and experiment, and provides opportunities for close collaboration with experts in photonics, nonlinear dynamics, and topological physics both within ETH and internationally. Applications are invited from motivated candidates who wish to contribute to pioneering synthetic lattice physics in photonics, with potential applications in spectroscopy, communications, and LIDAR. ETH Zürich is committed to diversity, sustainability, and providing an inclusive environment for all staff and students. Applicants must submit their materials online, including a cover letter, CV, academic transcripts, three professional references, and a sample publication or thesis. For questions about the position, contact Mr Alexander Dikopoltsev at [email protected].

PhD Position in Time-Reflection of Subwavelength THz Waves at ETH Zurich This PhD project at ETH Zurich explores new ways of controlling and confining electromagnetic waves in time, with a focus on terahertz (THz) time-varying photonic systems based on subwavelength waveguides. The research investigates how ultrafast excitations can modify a material’s optical properties on subcycle timescales, enabling emerging wave phenomena such as time reflection , dynamic dispersion engineering , photonic time crystals , and the dynamic Casimir effect . The project is jointly supervised within an ETH collaborative initiative and involves regular interaction with the groups of Prof. Dikopoltsev , Prof. Scalari , Prof. Johnson , and project partners. The work combines theoretical modeling , device design , and ultrafast THz experiments , offering a highly interdisciplinary environment at the interface of photonics, electromagnetism, and computational physics. The successful candidate will develop numerical simulation frameworks for time-varying electromagnetic systems, model ultrafast refractive-index modulation and temporal scattering, design and optimize subwavelength THz waveguides for efficient time interfaces, and study wave phenomena in periodically modulated guided systems. The project also includes collaboration with experimental partners to validate predictions through ultrafast THz pump–probe measurements . Applicants should have a background in physics, photonics, electrical engineering, or a related field , with experience or strong interest in numerical simulations (e.g. Maxwell solvers, FDTD/FEM, coupled-mode theory, or PDE/ODE solvers). Skills in scientific programming and data analysis with Python , MATLAB , or similar tools are desired, together with motivation to combine computation and experiment in a collaborative setting. ETH Zurich offers a unique environment with close collaboration with internationally recognized experts in THz photonics, ultrafast optics, and electromagnetic theory, and the chance to contribute to an emerging field with fundamental and technological relevance. How to apply: Applications must be submitted online as a single merged PDF, including a cover letter, CV, transcripts of all degrees in English, three professional reference contacts, and a publication or thesis sample. Questions about the position should be sent to Alexander Dikopoltsev at [email protected] . Email or postal applications will not be considered.