Wavelength-converted light sources in fluorescence-based methods in medical technology

This contribution proposes phosphors as excitation for fluorescence analysis and evaluates their potential in this application area. Aim of this research is to provide a method which allows to quantify how well a phosphor fits as excitation in a given optical system with spectral filters for fluorescence analysis. The approach consists of a mathematical calculation of crosstalk which is first applied to abstract and subsequentially defined phosphor emission spectra. The resulting crosstalk is used as measure indicating the fit of a phosphor spectrum. Result of this contribution is a detailed description of the applied method as well as an example exercise on a given optical system which gives an impression of possibilities phosphors offer in this application. The presented method is applicable to any (new) phosphor or even LED spectra. Especially evaluations on the example optical system allow conclusions which help to design future optical systems

Wavelength-converted light sources in fluorescence-based methods in medical technology

This contribution proposes phosphors as excitation for fluorescence analysis and evaluates their potential in this application area. Aim of this research is to provide a method which allows to quantify how well a phosphor fits as excitation in a given optical system with spectral filters for fluorescence analysis. The approach consists of a mathematical calculation of crosstalk which is first applied to abstract and subsequentially defined phosphor emission spectra. The resulting crosstalk is used as measure indicating the fit of a phosphor spectrum. Result of this contribution is a detailed description of the applied method as well as an example exercise on a given optical system which gives an impression of possibilities phosphors offer in this application. The presented method is applicable to any (new) phosphor or even LED spectra. Especially evaluations on the example optical system allow conclusions which help to design future optical systems

Lab-on-chip projection system for fluorescence based medical analysis

The aim of this research project is to implement a novel concept of using a scanning projection system for exciting fluorescence in lab-on-chip devices. While scanning projectors are state of the art in display applications, this use case imposes a set of specific requirements not fulfilled by commercial devices. One advantage in the lab-on-chip setting is increased flexibility in the design of disposables. To implement the final goal, the theoretical feasibility of the optical system is estimated, followed by simulation of the entire setup in Zemax OpticStudio and finally building up the working prototype of the projection system in the lab as a proof of concept, to compare the experimental findings with the simulation results

Lab-on-chip projection system for fluorescence based medical analysis

The aim of this research project is to implement a novel concept of using a scanning projection system for exciting fluorescence in lab-on-chip devices. While scanning projectors are state of the art in display applications, this use case imposes a set of specific requirements not fulfilled by commercial devices. One advantage in the lab-on-chip setting is increased flexibility in the design of disposables. To implement the final goal, the theoretical feasibility of the optical system is estimated, followed by simulation of the entire setup in Zemax OpticStudio and finally building up the working prototype of the projection system in the lab as a proof of concept, to compare the experimental findings with the simulation results

Sequential and non-sequential simulation of volume holographic gratings

Abstract Background In the development process of holographic displays like holographic Head-Mounted Displays (hHMD) the simulation of the complete optical system is strongly required. This especially includes the correct behaviour of the volume holographic grating (VHG) in terms of its optical function and its diffraction efficiency. The latter is not supported by the current version of Zemax®; OpticStudio 17, one of the most popular optic simulation tools. Methods To solve this problem we implemented a C++ code for each raytracing mode of Zemax®;, namely the sequential and non-sequential. The C++ code calculates the grating vector for every single ray traced. Based on the k-sphere formalism the propagation direction of the diffracted light is determined. Furthermore, its diffraction efficiency is defined according to Kogelnik’s coupled-wave theory. The C++ code is compiled and linked into Zemax®; using the Windows Dynamic Link Library (DLL). Results and discussion The aforementioned DLL enables the simulation of planar and arbitrarily spherical curved VHG and their diffraction efficiency within Zemax®; OpticStudio. This allows the fast, easy and reliable simulation of optical systems which include holograms or holographic optical elements, e.g. hHMD. Especially the simulation of VHG in non-sequential mode can be helpful in order to identify possible stray light paths. Conclusion The implemented C++ code enables the user to simulate VHG and its diffraction efficiency within Zemax®; Optic Studio