Bachelor- and master-thesis at BMO

If you are interested, please send the contact person a resume and a current grade transcript with your request.

Beam deflection system using a motorised polygon mirror for optical cohe-rence tomography

AG Huber - Bachelor Thesis

In optical coherence tomography, beam deflection systems based on galvanometric systems are often used to deflect a laser beam in the X and Y directions. These have the advantage that the pivot point is close to the mirrors. However, these systems are speed-limited, which is a problem for modern high-speed OCT systems. Polygon beam deflection systems achieve significantly higher speeds, but their mirrors are located well away from the pivot point.

Miniature drone motors and compact mirrors offer the potential to construct highly efficient polygon deflection systems. By achieving higher scanning speeds and positioning the pivot point in closer proximity to the mirror than conventional polygon scanners available in the market, it becomes possible to overcome speed limitations in OCT systems, paving the way for innovative applications.

The student's task is to select a suitable motor, develop a control system for the motor, design a polygon mirror, and characterize the beam deflection system.

No special previous knowledge is necessary, but a good level of motivation, independence, and good knowledge of the English language is required. Experience with motors or microcontrollers as well as programming experience is an advantage.

If you are interested, please write an e-mail to Marie Klufts and enclose your compendium of all achievements of your current studies.

GUI development for laser and microscope control

Internship/Master thesis

The fast microscopy technology that is being researched in the Karpf group is based on self-built laser sources. For this purpose, a complete control software was recently developed that controls the laser sources and microscope electronics using Arduino and Raspberry Pi. The task of this master internship is to develop a graphical user interface (GUI) for the laser control of our innovative SLIDE microscopes. Programming skills in C++ or Python are advantageous, but not a prerequisite. For GUI development, the ImGUI project can be accessed ( However, motivation and willingness to familiarise yourself with these programming languages and software are crucial.
This Master's internship offers you a unique opportunity to gain practical experience in a forward-looking research field and to become part of a dynamic team. The project can also be started as a research internship and then continued as a Master's thesis. 
If you are interested, please contact Stefan Meyer or Christian Stock.

Stimulated-Raman Amplified Pulsed FDML Laser

AG Karpf - Master Thesis

FDML lasers are rapid wavelength tunable laser sources. They are used in a wide range of biomedical imaging techniques, but often provide only low output powers. Thus, we often employ master-oscillator power amplifier (MOPA) architectures to modulate FDML lasers to short picosecond pulses and amplify them to kW pulse powers in fiber amplifiers (1). In this work, you will explore an alternative pulse amplification using stimulated Raman amplification (2, 3). A MOPA laser at 1030nm will be built to provide kW pulses, enabling amplification of an FDML laser around 1064nm in optical fibers. The goal is a pulsed SRS-FDML laser with kW pulses at 1064nm.

For more information, please contact: Matthea Thielking or Stefan Meyer

1.         S. Karpf and B. Jalali, Opt. Lett. 44, 1952 (2019).
2.         S. Karpf, M. Eibl, W. Wieser, T. Klein, and R. Huber, Nature Communications 6, 6784 (2015).
3.         R. H. Stolen and E. P. Ippen, Applied Physics Letters 22, 276 (1973).

ConnectedSLIDE: Realtime microscope system monitoring

AG Karpf - Master Thesis/Internship

Our current research includes the development of various microscope prototypes, which are only possible through the interaction of many different instruments and technologies. In case of a change of location of the system, the possibility of remote maintenance is therefore very important. In this project, a monitoring centre is to be implemented for this purpose. The monitoring includes the status and parameters of different instruments such as laboratory computers, laser source including amplifier stages and others. After implementing the interfaces, the information is to be displayed in real time on a web interface that will give engineers and scientists an overview of the current status of the system, regardless of their location.
The work is aimed at anyone who enjoys programming and would like to gain an insight into current research in biomedical optics.
If there is interest, but programming skills still need to be refreshed, the project can also be worked on in conjunction with the research internship.

For more information, please contact: Stefan Meyer

Im Rahmen des BMEL-Projekts „KIBioSense – Qualitätsüberwachung entlang der Lebensmittel-Prozesskette mittels Biosensoren und Künstlicher Intelligenz“

AG Rahmanzadeh

Im Rahmen des BMEL-Projekts „KIBioSense – Qualitätsüberwachung entlang der Lebensmittel-Prozesskette mittels Biosensoren und Künstlicher Intelligenz“ bieten wir eine Möglichkeit zur Anfertigung einer Bachelor- oder Masterthesis. Ziel des Projekts ist die Vermeidung von Lebensmittelabfällen und durchgängige Qualitätssicherung während der gesamten Lieferkette, entlang derer nicht-invasiv die Qualität für jedes einzelne Lebensmittel gemessen und protokolliert wird. Zur Bestimmung der Frische des Lebensmittels sollen dabei in die Verkaufsverpackung integrierte Sensoren (i. Bes. Sensorfolien) mittels Fluoreszenzspektroskopie gemessen werden. Im Rahmen der Tätigkeiten für die Bachelorthesis soll zunächst die bakterielle Belastung auf Lebensmitteln (vorrangig Fisch) bestimmt werden. Diese wird durch die Plate Count Methode ermittelt, welche im Laufe der Arbeit optimiert werden soll. Eine Optimierung soll im Hinblick auf den Zeitaufwand, als auch den Materialaufwand, pro Probe geschehen. Zeitgleich werden die entsprechenden Sensorfolien ausgelesen, sodass eine Korrelation zwischen Bakteriendichte auf dem Fisch und Ergebnis aus der Sensorauswertung erstellt werden kann.    

Bei Interesse kontaktieren Sie bitte: Ramtin Rahmanzadeh

4D SLIDE: Videorate volumetric SLIDE Microscopy

AG Karpf - Master Thesis

In this project, the fast image acquisition speed of 4,000 frames per second of SLIDE microscopy will be used to acquire volumetric two-photon images at >20 Hz volume rate (=video rates). Thus, optical nonlinear two-photon microscopy can be employed to acquire whole volumetric (3D) images in real time to image biomedical and dynamic cellular processes in intravital microscopy. Thus, this approach is called 4D-SLIDE (3D+time). In this project, you will explore this 4D-SLIDE technology and apply it in pressing biomedical problems.

If you are interested, please contact:Sebastian Karpf

Axial-scanned SLIDE Microscopy using diffractive optical elements (DOEs)

AG Karpf - Master Thesis

SLIDE microscopy has brought forth a highly rapid technology for two-photon microscopy by performing line scanning using a high-speed wavelength-tunable FDML laser. In this master thesis, a diffractive optical element (similar to a Fresnel lens) will be used to perform a high-speed (MHz) axial chromatic scan. Thus, a fast (24Hz) volumetric SLIDE microscopy acquisition can be achieved by scanning in axial (z-) direction by diffractive optics and in x- and y-direction by galvanometric scanner.

If you are interested, please contact: Sebastian Karpf


780nm Metabolic FLIM Imaging

AG Karpf - Master Thesis

This project build upon the successful preliminary work of a laser development master thesis. Here, a 1550nm fiber laser was developed and subsequently generated 780nm light via frequency doubling. This new light source was then applied to autofluorescence imaging and fluorescence lifetime imaging (FLIM). Autofluorescence FLIM of the co-enzymes NADH and FAD can be used to optically examine the metabolic state of cells without staining, and thus detect, for example, tumorous cell tissues. In this master thesis, the laser will be optimized to higher laser powers and subsequently used in autofluorescent metabolic FLIM imaging of different cell lines.

If you are interested, please contact: Sebastian Karpf

TICO-Raman Measurements using spontaneous Raman scattering with the SLIDE system

AG Karpf - Master Thesis

This Master thesis will draw on prior work in time-coded Raman scattering (TICO-Raman, Karpf et al., Nature Communications 2015) and SLIDE microscopy technology (Karpf et al., Nature Communications 2020) to extend high-speed two-photon microscopy SLIDE with a stain-free contrast mechanism (Raman scattering). This offers the potential in biomedical imaging to significantly expand specificity through molecular contrast and enables new applications as a multi-modal imaging system in the detection of cellular origins of disease.

If you are interested, please contact: Sebastian Karpf

Real-time temperature control for laser irradiations on the retina of the eye

AG Brinkmann - Bachelor Thesis

As part of a DFG-funded project, a new laser setup is being created in which we want to heat the retina with only one laser and measure the temperature increase in real time in parallel. The bachelor thesis includes optimisation of the setup, measurements on retina explants of pig eyes, and real-time recording and processing of the data. Cell vitality assays will be used to obtain a comparison of thermal damage as a function of temperature.Requirements: Experimental skills and programming experience.

If you are interested, please contact: Ralf Brinkmann

Set-up of Fourier ptychogaphic imaging and evaluation using machine learning

AG Rahlves - Master Thesis

Fourier ptychography is a high-resolution imaging method in which intensity images of a sample are acquired under coherent illumination at different angles of illumination. From the individual images, both a higher resolution image and the object phase can be reconstructed numerically without the need for interferometric images. This requires so-called phase retrieval algorithms for image reconstruction, such as the Gerchberg-Saxton algorithm. Alternatively, however, machine learning methods are becoming increasingly established to enable reconstruction. The aim of the thesis is first to build a simple Fourier ptychography imaging system. However, the focus will be on the implementation and evaluation of machine learning-based evaluation, which will be realised in Python using PyTorch or TensorFlow, for example.

If you are interested, please contact: Maik Rahlves