Characteristics of S-shaped waveguide structures by the annealedproton exchange process in LiNbO3

The loss of S-shaped waveguide bends in annealed proton-exchanged LiNbO₃ integrated optical devices is found to be dependent on the length of thermal annealing time. The minimum transition length required in order to have losses as low as 0.2 dB is 2.0 mm for a 0.1-mm lateral offset. Intersecting waveguides based on S-shaped structures have been characterized for passive crossovers. An angle greater than 6° is required to provide a crosstalk of less than -30 dB. At a particular angle, intersecting waveguides offer the possibility of making a 3-dB coupler if an insertion loss of 1.2 dB is not a big concern. Zero-gap couplers based on S-shaped structures have been characterized for applications as 3-dB couplers as well. This type of 3-dB coupler has a much lower insertion loss of roughly 0.4-0.5 dB. Both 3-dB intersecting waveguides and 3-dB zero-gap couplers are less sensitive to wavelength variations     

Experimental Study on Breakdown of Mobility Universality in 〈100〉-Directed (110)-Oriented pMOSFETs

This paper describes experimental determination of the value of eta in (110)-oriented SOI pMOSFETs by changing the SOI thickness and temperature. It is found for the first time that in the case of a lang100rang-directed channel, eta should be larger than unity, which implies the collapse of the mobility universality, when temperature is low or SOI thickness is ultimately thin. Possible mechanisms of the breakdown of the mobility universality are discussed     

The effects of carbon nanotubes on mechanical and thermal properties of woven glass fibre reinforced polyamide-6 nanocomposites

This paper presents a preliminary investigation on the effects of incorporating carbon nanotubes (CNT) into polyamide-6 (PA6) on mechanical, thermal properties and fire performance of woven glass reinforced CNT/PA6 nanocomposite laminates. The samples were characterized by tensile and flexural tests, thermal gravimetric analysis (TGA), heat distortion temperature (HDT) measurements, thermal conductivity and cone calorimeter tests. Incorporation of up to 2 wt% CNT in CNT/PA6/GF laminates improved the flexural stress of the laminates up to 36%, the thermal conductivity by approximately 42% and the ignition time and peak HRR time was delayed by approximately 31% and 118%, respectively.     

Wavelength sensitivity in directional couplers

Measured and calculated crosstalk ratios as a function of wavelength are compared for proton exchanged and annealed LiNbO₃ directional couplers at λ=1550 nm. The analytical technique employed models the experimentally determined wavelength sensitivities reasonably well. The analytical technique is further used to predict comparable functions for titanium indiffused couplers, and these results are compared to other calculations taken from the literature. No significant difference in sensitivity is noted between the two waveguide forming techniques