We report unique thermo-optical characteristics of DNA-Cetyl tri-methyl ammonium (DNA-CTMA) thin solid film with a large negative thermo-optical coefficient of -3.4 × 10-4/°C in the temperature range from 20°C to 70°C without any observable thermal hysteresis. By combining this thermo-optic DNA film and fiber optic multimode interference (MMI) device, we experimentally demonstrated a highly sensitive compact temperature sensor with a large spectral shift of 0.15 nm/°C. The fiber optic MMI device was a concatenated structure with single-mode fiber (SMF)-coreless silica fiber (CSF)-single mode fiber (SMF) and the DNA-CTMA film was deposited on the CSF. The spectral shifts of the device in experiments were compared with the beam propagation method, which showed a good agreement.
Bibliographical noteFunding Information:
Yonsei University National Research Foundation of Korea (NRF) (NRF-2012M3A7B4049800). This work was supported in part by the Institute of Physics and Applied Physics, Yonsei University, in part by the Nano Material Technology Development Program through NRF funded by the MSIP.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics