Abstract. Arrayed waveguide gratings (AWGs) are commonly used as multiplexers/demultiplexers in wavelength division multiplexing systems. We design and fabricate a coarse wavelength division multiplexing AWG with a wide free-spectral range. A gull-wing-shaped AWG layout and S-shaped AWG layout are used to understand a wide band range. The spectral difference between each layout is experimentally demonstrated. Our results indicate that the fabricated AWG is suitable for applications such as portable power meters. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

The luminescence intensity of 3.5MgO · 0.5MgF 2 · GeO 2 :Mn 4+ was enhanced by 143, 141, and 149% when MgF 2 was replaced with CaF 2 , SrF 2 , and BaF 2 , respectively. MgF 2 contributes to the enhancement of the phosphor crystallinity by inserting F − into the structure and by decreasing the phase formation temperature. Because CaF 2 , SrF 2 , and BaF 2 not only supply F − to the host but also function as fluxes, they can improve the crystallinity more effectively than MgF 2 . A light emitting diode ͑LED͒ lamp with 3.5MgO · 0.5SrF 2 · GeO 2 :Mn 4+ and Y 3 Al 5 O 12 :Ce 3+ ͑YAG͒ shows a stable performance for various forward currents and higher color rendering index than that observed in a conventional YAG-based white LED lamp.