Postdoctoral scholarship (2 years) in hollow-core fiber design for next-generation communication

The Department of Applied Physics and Electronics at Umeå University is offering a postdoctoral scholarship for a project that aims to develop hollow-core optical fibers for next-generation communication (including 6G). The postdoctoral scholarship is full-time for 2 years starting Sept 1, 2025, or by agreement. The deadline for submitting an application is May 16, 2025.

Project description
The Internet is enabled by a network of silica fibers with a step-index profile. Since the invention of the optical fiber 50 years ago, its design has not been radically changed. During the last 10 years, it has been discovered that a new class of hollow-core fibers (HCFs) can potentially provide several key advantages over conventional fibers, including lower propagation loss, lower latency (due to the faster speed of light in air than in glass), lower nonlinearity and dispersion, and the liberty of choosing light wavelengths in a wider spectral range. These HCFs are based on anti-resonant reflection by sub-micron-thick silica membranes. Despite breakthroughs, significant challenges remain in both HCF design and fabrication. Further development of HCFs requires fundamental understanding of light-guidance principles as well as material properties of extremely thin silica membranes.

As a postdoctoral fellow in this project, you will have the opportunity to primarily carry out:

• electromagnetic analyses, including finite-element simulation and topological optimization of light guidance in HCFs, and
• numerical simulation of thermo- and fluid dynamics under fiber-drawing processes.

Apart from the main tasks above, the postdoc can be involved in the following research areas if interest arises:

• characterization of fabricated HCFs (both structural and optical transmission properties), and
• experimental investigations of material properties of ultra-thin silica membranes (through e.g. transmission-electron microscopy).

The scholarship is for two (2) years and is funded by the Kempe Foundations. The tax-free scholarship amounts to 720 000 SEK in total (360 000 SEK annual average) and is usually paid out as four separate payments during scholarship period.

This project is running in parallel with another larger project with partners including RISE High-Speed Transmission Lab (Kista, Stockholm), RISE Fiberlab (Hudiksvall), Chalmers University of Technology (Gothenburg), as well as the companies Ericsson, Telia and Telenor.

Qualifications
To qualify as a postdoctoral scholarship holder, the candidate is required to have completed a doctoral degree or a foreign degree deemed equivalent to a doctoral degree. This requirement must be fulfilled no later than at the time of the final decision about the scholarship recipient.

Priority will be given to candidates who completed their doctoral degree, according to what is stipulated in the paragraph above, no later than three years prior. If there are special reasons, candidates who completed their doctoral degree before that may also be eligible. Special reasons include absence due to illness, parental leave, appointments of trust in trade union organizations, military service, or similar circumstances, or other forms of appointment/assignment relevant to the subject area.

The doctoral degree should be in a subject relevant to the project, such as physics.

Fluency in English, both in oral and written forms, is mandatory.

The candidate should have a strong interest in physics (especially optics), numerical methods, and basic knowledge of material science.

It is meriting to have one or more of the following skills/qualities:

• experience and/or thorough understanding of theoretical/numerical methods for simulating optical phenomena
• experience in fabrication and/or characterization of micro- or nanostructures

We are looking for candidates who are highly motivated, goal-oriented, capable of critical thinking, and willing to collaborate with other members in a team.

Application
A complete application should include:

1. A cover letter summarizing your qualifications, your scientific interests, your motives for applying, and how you feel you meet the essential and meriting criteria (max 2 pages);
2. Curriculum vitae (CV) with publication list;
3. Copy of doctoral degree certificate or documentation that clarifies when the degree of doctor is expected to be obtained;
4. Copy of doctoral thesis (PDF or a download link);
5. Copies of other diplomas (master and bachelor studies);
6. A list of university courses with grades (transcripts). Note that for international applicants the grading system should be explained in brief;
7. Contact information of at least two reference persons;
8. (optional) Other documents that the applicant wishes to supply.

The application, including attached documents, must be written in English or Swedish. Documents sent electronically must be in PDF format. The application is made through our electronic recruitment system Varbi. Application closing date is 16 May 2025.

Further information
For more information, please contact Max Yan (max.yan@umu.se), or head of department Britt Andersson (britt.andersson@umu.se).

We look forward to receiving your application!