Bragg gratings are inscribed in an all-solid photonic bandgap fiber by use of femtosecond laser irradiation. Dualpeak structure is observed in the transmission spectrum of the induced grating, which is formed by the coupling between the forward-propagating fundamental core mode and the backward-propagating core mode or supermode. Sensing characteristics of the device are investigated experimentally by employing strain and temperature tests, and similar behavior is obtained for both resonant peaks. The strain and temperature sensitivities are 0.968pm/𝜇𝜀 and 12.01pm/ ∘ C, and 0.954pm/𝜇𝜀 and 12.04pm/ ∘ C, for the two peaks, respectively. This device would find potential applications in real optical fiber sensing without extra reference gratings.

We performed a subjective experiment measuring perceived overhead glare from a fluorescent luminaire with either a Correlated Color Temperature (CCT) of 4000K or 6300K. The group of 18 participants was equally divided over males and females, and almost equally over subjects wearing glasses and subjects without glasses. The results show that a light source with a higher CCT induces statistically significantly more overhead glare. In addition, differences in perceived overhead glare cannot be attributed to either gender or visual correction means.

An ytterbium-doped double-clad fiber laser with one-end pumped by four 915 nm laser diodes (LDs) combined by a homemade multimode fused fiber bundle combiner is proposed. The combiner, fused by splicing four fiber pigtails from diodes, exhibits a good capability of low-loss and a high efficiency of 92.7%. The fiber laser, which can generate a continuous-wave (CW) up to 10.3 W output power at 1104 nm with a homemade D-shape inner cladding ytterbium-doped fiber, is demonstrated. The slope efficiency is about 65% and the optical-to-optical conversion efficiency with respect to the pump power is 46% at its maximum output laser power.

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