Erbium-doped Si nanocrystal based optical waveguides were formed by Er and Si ion implantation into SiO2 . Optical images of the waveguide output facet show a single, well-confined optical mode. Transmission measurements reveal a clear Er related absorption of 2.7 dB/cm at 1.532 mm, corresponding to a cross section of 8310 cm. The Si nanocrystals act as sensitizers for Er but under high doping ...

This work describes the comparison of the amplification characteristics (gain) and the Noise figure (NF) of the Thulium and Erbium in three different host materials which the Yttria Alumina-Silica glass, Fluoride and Tellurite fiber glass. The gain using these host materials covers the range 1.45-1.65 μm. Thulium doped fiber amplifier (TDFAs) operated in the region of wavelength (1480-1510 nm) ...

The purpose of this study was to compare threshold-matched ears with and without suspected cochlear dead regions in terms of the speech perception benefit from high-frequency amplification. The Threshold Equalizing Noise Test (TEN) was used to assess the presence of dead regions. Speech perception was measured while participants were wearing a hearing aid fit to approximate DSL[i/o] targets. Co...

PURPOSE To evaluate the functional outcome and macular index in patients with macular hole who underwent surgery with internal limiting membrane removal. METHODS Fifteen eyes of 15 patients with idiopathic macular hole stages 2, 3 or 4 were enrolled in this study. All patients underwent conventional macular hole surgery with trypan blue staining to remove the internal limiting membrane. The b...

Erbium doped Al2O3 waveguide amplifiers were fabricated using two different doping methods, namely Er ion implantation into sputter deposited Al2O3 , and co-sputtering from an Er2O3 /Al2O3 target. Although the Er concentration in both materials is almost identical ~0.28 and 0.31 at. %!, the amplifiers show a completely different behavior. Upon pumping with 1.48 mm, the co-sputtered waveguide sh...

In this paper, a new algorithm with multi constraints that can be used in active noise control is presented. This can be used to maintain the particular system power budget and prevent over driving. The filter used for the constraints is frequency domain of least mean square algorithm. A limiting factor is used in the algorithm to reduce the effect of the filter response at other frequencies. T...

A B S T RA C T Synaptic transmission from secondto third-order neurons of cockroach ocelli occurs in an exponentially rising part of the overall sigmoidal characteristic curve relating preand postsynaptic voltage. Because of the nonlinear nature of the synapse, linear responses of second-order neurons to changes in light intensity are half-wave rectified, i.e., the response to a decrement in li...

Synaptic transmission from second- to third-order neurons of cockroach ocelli occurs in an exponentially rising part of the overall sigmoidal characteristic curve relating pre- and postsynaptic voltage. Because of the nonlinear nature of the synapse, linear responses of second-order neurons to changes in ligh intensity are half-wave rectified, i.e., the response to a decrement in light is ampli...