Technical University of Denmark (DTU)

PhD position on Optical Time-Lenses for Passive Optical Networks

Technical University of Denmark (DTU)

2800 Kgs. Lyngby, Denmark

This project aims to advance the state of the art in time-lens based technologies for high capacity passive optical access networks (PONs) and utilize their potential for energy-efficiency. You will contribute to developing novel optical processing units and schemes by developing linear/nonlinear components optimized for broadband applications and advanced sub-systems based on optical time lenses. You will explore novel ways of using integrated optical circuits for ultrahigh capacity energy-efficient optical access networks beyond the ‘techno barriers’, and, as a team, we will demonstrate 10 times more capacity and orders of magnitude more energy efficient systems.

In our group, we are exploring a new highly flexible and scalable optical line terminal (OLT) structure based on time lens optical Fourier transformation (OFT) for optical access networks. We aim to improve the stability and decrease the size of such a system by integrating its functionality onto a monolithic silicon photonic platform. You will design the dispersion-engineered waveguides to have a flat second order dispersion and fabricate them in the DTU Nanolab cleanroom. The experimental part will include extensive system characterizations of the developed time-lens PON (Lens-PON) system. In this process, you will acquire a solid experience in optical communication systems and photonic integrated circuit design.

Responsibilities and tasks
This PhD position will investigate the research topics below using both experimental and theoretical methods, but not limited to these topics:

  • Model the time-lens processer for Lens-PON, spanning from FDTD modelling of devices to circuit-level simulations.
  • Design photonic integrated circuits with optimum dispersion and nonlinear properties. You will use a silicon photonics platform, using a hybrid combination of materials for the linear and nonlinear components. You will assess which material (e.g., silicon nitride, amorphous silicon, crystalline silicon, or aluminum gallium arsenide) is appropriate for each component and develop the hybrid platform based on your assessment.
  • Using the developed hybrid platform, you will design and optimize an on-chip time-lens signal processor.
  • Demonstrate a Lens-PON system experimentally.

As part of the Danish PhD program, the student will follow a number of Ph.D. courses as well as take part in teaching. Furthermore, there will be the opportunity to carry out a longer external research stay. We have close collaborations with numerous internationally leading universities and research organizations.

Candidates should have a two-year master’s degree (120 ECTS points) or a similar degree with an academic level equivalent to a two-year master’s degree.

Approval and Enrolment
The scholarship for the PhD degree is subject to academic approval, and the candidate will be enrolled in one of the general degree programmes at DTU. For information about our enrolment requirements and the general planning of the PhD study programme, please see the DTU PhD Guide.

We offer
DTU is a leading technical university globally recognized for the excellence of its research, education, innovation and scientific advice. We offer a rewarding and challenging job in an international environment. We strive for academic excellence in an environment characterized by collegial respect and academic freedom tempered by responsibility.

Salary and appointment terms
The appointment will be based on the collective agreement with the Danish Confederation of Professional Associations. The allowance will be agreed with the relevant union. The period of employment is 3 years.

Will be at DTU Fotonik, Department of Photonics Engineering, at the Kgs. Lyngby Campus

You can read more about career paths at DTU here.

Further information
Further information may be obtained from Senior Researcher Pengyu Guan ( and Postdoc Peter David Girouard (

You can read more about DTU Fotonik on

Please submit your online application no later than 10 December 2019 (local time).

Apply online at

Applications must be submitted as one PDF file containing all materials to be given consideration. To apply, please open the link “Apply online”, fill out the online application form, and attach all your materials in English in one PDF file. The file must include:
  • A letter motivating the application (cover letter)
  • Curriculum vitae
  • Grade transcripts and BSc/MSc diploma
  • Excel sheet with translation of grades to the Danish grading system (see guidelines and Excel spreadsheet here)

Candidates may apply prior to ob­tai­ning their master’s degree but cannot begin before having received it.

Applications and enclosures received after the deadline will not be considered.

All interested candidates irrespective of age, gender, race, disability, religion or ethnic background are encouraged to apply.

DTU Fotonik has 210 employees with competences in optics and is one of the largest centers in the world based solely on research in photonics. Research is performed within optical sensors, lasers, LEDs, photovoltaics, ultra-high speed optical transmission systems, bio-photonics, nano-optics and quantum photonics.

Technology for people
DTU develops technology for people. With our international elite research and study programmes, we are helping to create a better world and to solve the global challenges formulated in the UN’s 17 Sustainable Development Goals. Hans Christian Ørsted founded DTU in 1829 with a clear vision to develop and create value using science and engineering to benefit society. That vision lives on today. DTU has 11,500 students and 6,000 employees. We work in an international atmosphere and have an inclusive, evolving, and informal working environment. Our main campus is in Kgs. Lyngby north of Copenhagen and we have campuses in Roskilde and Ballerup.

Please apply via recruiter’s website.