We present a hybrid optical filter design that combines interference and absorbing components for enhanced fluorescence detection in miniaturized highly-integrated lab-on-a-chip devices. The filter is designed in such a way that the advantages of each technology are used to offset the disadvantages of the other. The filter is fabricated with microfabrication compatible processes and materials for monolithic integration with microelectronics and microfluidics devices. The particular embodiment of the filter described herein is designed to discriminate fluorescence emission at 650 nm from excitation at 532 nm. The 9-layer interference filter component is fabricated with alternating TiO(2) and SiO(2) thin-film layers and has an attenuation of -12.6 dB at 532 nm and -0.76 dB at 650 nm. The absorbing filter component is fabricated using a dyed photopolymer (KMPR + Orasol Red) having an attenuation of -32.6 dB at 532 nm and -1.28 dB at 650 nm. The total rejection ratio of the hybrid filter is 43 dB. The filter exhibits very low autofluorescence and performs equally well at off-axis incidence angles.

This paper presents a buried quad p-n junction (BQJ) photodetector fabricated with a HV (high-voltage) CMOS process. Multiple buried junction photodetectors are wavelength-sensitive devices developed for spectral analysis applications where a compact integrated solution is preferred over systems involving bulk optics or a spectrometer due to physical size limitations. The BQJ device presented here is designed for chip-based biochemical analyses using simultaneous fluorescence labeling of multiple analytes such as with advanced labs-on-chip or miniaturized photonics-based biosensors. Modeling and experimental measurements of the spectral response of the device are presented. A matrix-based method for estimating individual spectral components in a compound spectrum is described. The device and analysis method are validated via a test setup using individually modulated LEDs to simulate light from 4-component fluorescence emission.

Silicon photomultipliers are regarded as a very promising technology for nextgeneration, cutting-edge detectors for low-background experiments in particle physics. This work presents systematic reflectivity studies of Silicon Photomultipliers (SiPM) and other samples in liquid xenon at vacuum ultraviolet (VUV) wavelengths. A dedicated setup at the University of Münster has been used that allows to acquire angle-resolved reflection measurements of various samples immersed in liquid xenon with 0.45 • angular resolution. Four samples are investigated in this work: one Hamamatsu VUV4 SiPM, one FBK VUV-HD SiPM, one FBK wafer sample and one Large-Area Avalanche Photodiode (LA-APD) from EXO-200. The reflectivity is determined to be 25-36 % at an angle of incidence of 20 • for the four samples and increases to up to 65 %

Incident electron beam parameters of Monte Carlo linear accelerator model are typically determined by comparing computed profiles and depth‐dose curves with measurements. Several variations have been suggested in literature: Sheikh 2002 used kerma equivalent off‐axis factors while van der Zee 1999 used cross profiles in large water phantom. In this study, we compared both methods. The BEAMnrc and DOSXYZnrc codes are used to simulate 6MV and 25MV photon beam from medical linear accelerator Elekta SL25. The mean energy and radial width of the incident electron beam intensity distributions (assumed Gaussian and cylindrically symmetric) are derived by both in air and in water technique. Excluding region of electronic disequilibrium (build‐up and penumbra) local dose difference between simulated and measured curves must be under 2% to found agreement. The statistical uncertainties on calculated dose at each point is about 0.7% (or better) at 1 sigma level. We show that off‐axis curves are more sensitive to mean energy of electron beam than depth‐dose curves. The matching mean energy and radial parameters of the incident electrons beam (6MV & 25MV) for both in air and in water technique converge within 6%. Particular attention is also devoted to measurement in air and their consequences on matching parameters.