TY  - JOUR
A1  - Boggio, Jose M. Chavez
A1  - Bodenmueller, D.
A1  - Fremberg, T.
A1  - Haynes, R.
A1  - Roth, Martin M.
A1  - Eisermann, R.
A1  - Lisker, M.
A1  - Zimmermann, L.
A1  - Boehm, Michael
T1  - Dispersion engineered silicon nitride waveguides by geometrical and refractive-index optimization
JF  - Journal of the Optical Society of America : B, Optical physics
N2  - Dispersion engineering in silicon nitride (SiXNY) waveguides is investigated through the optimization of the waveguide transversal dimensions and refractive indices in a multicladding arrangement. Ultraflat dispersion of -84.0 +/- 0.5 ps/nm/km between 1700 and 2440 nm and 1.5 +/- 3 ps/nm/km between 1670 and 2500 nm is numerically demonstrated. It is shown that typical refractive index fluctuations as well as dimension fluctuations during fabrication of the SiXNY waveguides are a limitation for obtaining ultraflat dispersion profiles. Single- and multicladding waveguides are fabricated and their dispersion profiles measured (over nearly 1000 nm) using a low-coherence frequency domain interferometric technique. By appropriate thickness optimization, the zero-dispersion wavelength is tuned over a large spectral range in single-and multicladding waveguides with small refractive index contrast (3%). A flat dispersion profile with +/- 3.2 ps/nm/km variation over 500 nm is obtained in a multicladding waveguide fabricated with a refractive index contrast of 37%. Finally, we generate a nearly three-octave supercontinuum in this dispersion flattened multicladding SiXNY waveguide. (C) 2014 Optical Society of America
Y1  - 2014
U6  - https://doi.org/10.1364/JOSAB.31.002846
SN  - 0740-3224
SN  - 1520-8540
VL  - 31
IS  - 11
SP  - 2846
EP  - 2857
PB  - Optical Society of America
CY  - Washington
ER  - 
TY  - JOUR
A1  - Schmaelzlin, Elmar
A1  - Moralejo, Benito
A1  - Rutowska, Monika
A1  - Monreal-Ibero, Ana
A1  - Sandin, Christer
A1  - Tarcea, Nicolae
A1  - Popp, Juergen
A1  - Roth, Martin M.
T1  - Raman imaging with a fiber-coupled multichannel spectrograph
JF  - Sensors
N2  - Until now, spatially resolved Raman Spectroscopy has required to scan a sample under investigation in a time-consuming step-by-step procedure. Here, we present a technique that allows the capture of an entire Raman image with only one single exposure. The Raman scattering arising from the sample was collected with a fiber-coupled high-performance astronomy spectrograph. The probe head consisting of an array of 20 x 20 multimode fibers was linked to the camera port of a microscope. To demonstrate the high potential of this new concept, Raman images of reference samples were recorded. Entire chemical maps were received without the need for a scanning procedure.
KW  - multichannel Raman spectroscopy
KW  - astronomy spectrograph
KW  - optical fiber bundle
KW  - Raman imaging
Y1  - 2014
U6  - https://doi.org/10.3390/s141121968
SN  - 1424-8220
VL  - 14
IS  - 11
SP  - 21968
EP  - 21980
PB  - MDPI
CY  - Basel
ER  -