研究実績の概要 |
Within this year, we have conducted the optimization, simulation, fabrication, and experiment processes. First, we optimized the structure by adjusting the DBR layer number and the DBR material, for a fully developed optical Tamm state sustained within the structure. As a result, through simulation, we demonstrated a pronounced resonance peak in emittance spectrum with a quality factor (Q-factor) as large as 1908 . Ge was used, not only as a material of the DBR, but also for wavelength tunability taking advantage of its thermo-optic effect. The temperature sensitive Ge layer was designed at the position sustaining the maximum electric field, in order to make the index change in Ge maximally influence the optical behavior of the whole structure. Then, the device has been fabricated using RF sputtering. To reduce its internal stress, we also annealed the sample after deposition. The emittance measurement was carried out at temperatures up to 150 C. Upon heating, sharp peak is observed in the emittance spectrum with a large Q-factor around 780.
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