Measurement of refractive index of single microparticles

The refractive index of single microparticles is derived from precise measurement and rigorous modeling of the stiffness of a laser trap. We demonstrate the method for particles of four different materials with diameters from 1.6 to 5.2 microns and achieve an accuracy of better than 1%. The method greatly contributes as a new characterization technique because it works best under conditions (small particle size, polydispersion) where other methods, such as absorption spectroscopy, start to fail. Particles need not be transferred to a particular fluid, which prevents particle degradation or alteration common in index matching techniques. Our results also show that advanced modeling of laser traps accurately reproduces experimental reality

Waveguide length and pump power effects on the amplification of europium aluminum doped polymer

Mosquito method is used to fabricate a 50 μm core diameter graded index (GI) multimode Eu-Al doped polymer composite optical waveguide amplifier. In this paper, waveguide length and pump power are varied with an input signal of - 30 dB m. Under a 532 nm laser excitation, 16.27 dB optical gain under an optimal 10 cm waveguide length is observed from forward pumping amplification for a threshold pump power of 23 dB m. Also, the waveguide has been characterized to be 0.83 dB/cm at 617 nm wavelength

Planar polymer and glass graded index waveguides for data center applications

Embedded optical waveguide technology for optical printed circuit boards (OPCBs) has advanced considerably over the past decade both in terms of materials and achievable waveguide structures. Two distinct classes of planar graded index multimode waveguide have recently emerged based on polymer and glass materials. We report on the suitability of graded index polymer waveguides, fabricated using the Mosquito method, and graded index glass waveguides, fabricated using ion diffusion on thin glass foils, for deployment within future data center environments as part of an optically disaggregated architecture. To this end, we first characterize the wavelength dependent performance of different waveguide types to assess their suitability with respect to two dominant emerging multimode transceiver classes based on directly modulated 850 nm VCSELs and 1310 silicon photonics devices. Furthermore we connect the different waveguide types into an optically disaggregated data storage system and characterize their performance with respect to different common high speed data protocols used at the intra and inter rack level including 10 Gb Ethernet and Serial Attached SCSI

Status of plastic optical fibres and related technologies

Recent results will be presented in the development of graded index polymer optical fibers (GIPOF) and systems. The bandwidth of the fiber will be discussed and record results of high capacity system experiments that use wavelengths around 645 nm, 840 nm, and 1300 nm are reviewed. WDM experiments are addressed, reporting recent 2.5 Gbit/s WDM transmission results. We also discuss the environmental conditions on the perfonnance of the fiber

esu) of cyanine dye J aggregates doped silica film synthesized by a simple solÁ/ gel method

We have synthesized, for the first time, a thin silica film doped with condensed J aggregates of 1,1?-diethyl-2,2?-cyanine bromide / / dye using a simple sol Á/gel method. The film is homogeneous in thickness and stable at room temperature. The J band formed in the / / spin coating process is independent of polarizer angle and the film is isotropic without any dichroism. The high optical nonlinearity / / (x 3 0/5.0 )/10 (7 esu) of the film at the resonance wavelength (0/577 nm) of the J aggregates was first observed by Z -scan using a / / 180 fs pulse laser at 77 K under a vacuum ( B/10 (5 torr). The doping ratio of J aggregates in silica film suggests that the net j