The semiconductor device comprises a semiconductor layer 18 formed on an insulation layer 16, a gate electrode 22 formed on the semiconductor layer with a gate insulation film 20 formed therebetween, a sourcedrain region 24 formed on the semiconductor layer on both sides of the gate electrode, and a semiconductor region 14 buried in the insulation layer 16 in a region below the gate electrode. Oxygen barrier containing photoinitiator is used to cure incompletely cured lens portions. The FFT engine utilizes a minimal number of multipliers to perform the twiddle multiplications in an efficient pipeline. A display is configured to display a visual indicator in the current field of view of the user. The quality of service of the IP telephony network is evaluated according to characteristics associated with the test signal. In some embodiments, a spectral distortion associated with a pass-through wavelength signal spectrally adjacent to one of the one or more guard-channels is no more than three decibels after exiting the last of the plurality of low distortion OADMs.