@inproceedings{MeisterSchwedaDziedzinaetal.2010, author = {Meister, Stefan and Schweda, Dawid and Dziedzina, Marcus and Al-Saadi, Aws and Franke, B{\"u}lent A. and Scharfenorth, Chris and Grimm, Bernd and Dufft, Daniela and Schrader, Sigurd and Eichler, Hans J.}, title = {Single cavity filters on end-faces of optical fibers}, publisher = {Society of Photo-Optical Instrumentation Engineers (SPIE)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15214}, pages = {253 -- 261}, year = {2010}, abstract = {We have developed thin film Fabry-Perot filters directly coated on optical fibers to archive a high level of integration with a reduction of optical elements. Such band-pass filters can be used in fiber optical sensor systems, and for fiber communication, e.g. CWDM applications. The filters cavities consist of a single spacer and two dielectric mirrors. The dielectric mirrors are deposited by PVD directly on end-faces of single-mode optical fibers. Dielectric as well as polymeric materials were applied as the spacer layer. Polymeric spacer layers were deposited by dip coating. The influence of the mirror reflectivity on the transmission band of the Fabry-Perot filters was investigated. Furthermore, the optical performance of filters with first order (λ/2) as well as higher order spacers was analyzed. The experimental results are compared with numerical analysis of Fabry-Perot cavities on the end-face of cylindrical waveguides. The spectral characteristic of the filters are calculated using a software solving Maxwell´s equations by a FDTD method. The layer design of the filters and the deposition process were optimized for maximum transmission and narrow bandwidth of the transmission peak. Passive band-pass filters on fiber end-faces were designed, fabricated and characterized for transmission wavelengths of 945 nm, 1300 nm, as well as 1550 nm. Bandwidths as narrow as 1 nm could be achieved for 945 nm.}, language = {en} } @inproceedings{MeisterAlSaadiFrankeetal.2010, author = {Meister, Stefan and Al-Saadi, Aws and Franke, B{\"u}lent A. and Mahdi, Shaimaa and Kuhlow, Berndt and Voigt, Karsten and Tillack, Bernd and Richter, Harald H. and Zimmermann, Lars and Ksianzou, Viachaslau and Schrader, Sigurd and Eichler, Hans J.}, title = {Photonic crystal microcavities in SOI waveguides produced in a CMOS environment}, publisher = {Society of Photo-Optical Instrumentation Engineers (SPIE)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15223}, pages = {330 -- 339}, year = {2010}, abstract = {We have investigated microcavities in Silicon-on-Insolator (SOI) waveguides. The rectangular waveguides with 500 nm width are fabricated in the 220 nm silicon device layer. The microcavities are formed by one-dimensional photonic crystals in Fabry-Perot structure directly written in the waveguides. The SOI photonic structures are produced in a CMOS environment using 248 nm DUV lithography, where the waveguides as well as the photonic crystals are created in the same step using a single mask. In order to achieve a desired spectral shape of the filter function capable for several applications, a number of different cavities were investigated, e.g. single cavities of first and higher order as well as multi-cavity filters. The experimental results are compared with simulations of photonic crystal microcavities in strip waveguides. The spectral transmission function of such filters dependent on the design parameters are calculated by an analysis based on Finite-Difference-Time-Domain (FDTD) method.}, language = {en} } @inproceedings{MeisterAlSaadiFrankeetal.2011, author = {Meister, Stefan and Al-Saadi, Aws and Franke, B{\"u}lent A. and Mahdi, Shaimaa and Szczambura, Miroslaw and Kuhlow, Berndt and Woggon, Ulrike and Zimmermann, Lars and Richter, Harald H. and Stolarek, David and Schrader, Sigurd and Eichler, Hans J.}, title = {Micro-cavities based on width modulated SOI waveguides}, publisher = {Society of Photo-Optical Instrumentation Engineers (SPIE)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15233}, pages = {199 -- 204}, year = {2011}, abstract = {We have designed, fabricated and investigated one-dimensional (1D) micro-cavities in Silicon-on-Insulator (SOI) waveguides. The single mode waveguides are fabricated in a 220 nm silicon device layer. The 1D micro-cavities in Fabry-Perot structure consist of two Bragg-mirror regions formed by a sinusoidal modulation of the waveguide width. The mirror regions are separated by a sub-micron spacer. The SOI photonic structures are produced in a CMOS environment using 248 nm DUV lithography. The waveguides as well as the width modulated mirror regions are designed using a single mask and are fabricated in a shallow trench process. The transmission spectra of these width modulated micro-cavities with different mirror reflectivities and cavity lengths are investigated. Q-factors up to 855 could be observed at 1550 nm wavelength with low insertion loss of 1.9 dB. The width modulated micro-cavities, including the mirror regions, have lengths of less than 20 microns and widths of maximum 450 nm. These small foot-print cavities act as band pass filters and can be used as resonators for laser or electro-optic modulation of light.}, language = {en} } @inproceedings{WangMeisterMahdietal.2011, author = {Wang, Sha and Meister, Stefan and Mahdi, Shaimaa and Franke, B{\"u}lent A. and Al-Saadi, Aws and Zimmermann, Lars and Richter, Harald H. and Stolarek, David and Lisinetskii, Viktor and Ksianzou, Viachaslau and Schrader, Sigurd and Eichler, Hans J.}, title = {Spontaneous and stimulated Raman scattering in planar silicon waveguides}, publisher = {Society of Photo-Optical Instrumentation Engineers (SPIE)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-15248}, pages = {281 -- 289}, year = {2011}, abstract = {Raman scattering in planar silicon on insulator (SOI) waveguides with 2 μm width, 220 nm height and 2 cm length is investigated. A cw Nd:YAP laser at 1340.6 nm with 7 GHz FWHM spectral width is used as the pump source. A lensed fiber of 2.5 μm focus diameter is used to couple the pump laser into the waveguide. The coupling efficiency is estimated to be around 10\%. Spontaneous Raman scattering is observed with as low as 2.5 mW pump power inside the waveguide. The spontaneous Raman spectrum is measured by an optical spectrum analyzer. The first order Raman peak is measured at around 1441.4 nm corresponding to a Raman shift of 15.6 THz, while the FWHM of Raman spectrum is measured as around 100 GHz. Maximum Raman output of around 90 pW is obtained by around 22 mW pump. The stimulated Raman gain coefficient is estimated as around 56 cm/GW from the relationship between spontaneous Raman output power and pump power. A temperature dependence of Raman frequency shift of about 0.6 GHz/K is measured. The spontaneous anti-Stokes Raman scattering output peak at 1253 nm is also observed with around 35 mW pump. Stimulated Raman amplification measurement is carried out with a SLED white light source as probe signal. With 35 mW pump power, around 0.6 dB gain has been determined with both pump and probe being TE polarized.}, language = {en} }