1 PhD Scholarship in Low-noise Supercontinuum Lasers for Optical Coherence Tomography systems in Denmark | Technical University of Denmark (DTU)

The Fiber Sensors & Supercontinuum Group at DTU Fotonik, Department of Photonics Engineering at the Technical University of Denmark is seeking a PhD student for a 3-year Scholarship in the field of supercontinuum lasers for Optical Coherence Tomography (OCT) systems operating in the mid-infrared. The position is funded by the project “Spectrally shaped supercontinuum sources for high-resolution Optical Coherence Tomography medical imaging and non-destructive testing” (ShapeOCT).

Summary of the project ShapeOCT

ShapeOCT will use Danish strongholds in supercontinuum (SC) light source and photonic crystal fiber (PCF) technology to develop a new generation of SC light sources with shaped noise and power spectra that are optimal for use in a new generation of ultra-high resolution Optical Coherence Tomography (UHROCT) systems. Noise reduction and spectral shaping of the SC will be done by intricate dispersion design and using normal dispersion femto-second pumping, fiber tapering and concatenation. Three state-of-the-art spectral domain UHROCT systems will be developed that operate (I) at 1.3µm with a low-noise SC source using a silica PCF, and (II, III) in the mid-infrared (MIR) at 4 and 7µm with an SC source using a ZBLAN and chalcogenide fiber, respectively. The improved resolution of UHROCT system (I) will be evaluated against a commercial OCT system in skin cancer diagnostics. All UHROCT systems I-III are highly suited for non-destructive testing (NDT) and will be evaluated against each other and existing OCT systems for their increased resolution and penetration depth in testing of fiber-reinforced polymer (emerging construction material). For the MIR SC sources and OCT systems ShapeOCT will invest in state-of-the-art equipment for fiber drawing and glass manufacturing to establish a chalcogenide MIR fiber technology platform in Denmark and move the SC source into the 3-12µm molecular fingerprint region, which is of fundamental importance for not just OCT, but also for ultra-fast spectroscopy tools for cancer detection, pollution, and food and soil quality monitoring. Nano-imprinting of the end-facet of chalcogenide fibers will be developed for improved power handling and low loss coupling (today 40% Fresnel loss is suffered), and ultra-broadband MIR detectors will be developed based on upconversion.

Responsibilities and tasks

The selected PhD student will participate in a project team of 4 postdocs and 4 PhD students hired specifically on the project, in addition to the participating senior staff. The student will specifically be in charge of the modelling of SC generation and the development of low-noise SC sources for the UHROCT systems. The student is thus expected to:

• Develop software for the modelling of SC generation in tapered optical fibers
• Develop software for analysis of SC noise performance
• Take part in experimental optical fiber and SC characterization
• Interact with the company NKT Photonics A/S and spend a period at the company
• Interact with the Université de Franche-Comté in Besancon, France, and spend a period of several month there for training in femtosecond SC generation