Tunable thin-film filter with low angle sensitivity
Kan Yu , Jia-qi Bao , Juan-juan Yin
Optoelectronics Letters ›› : 338 -341.
Tunable thin-film filter with low angle sensitivity
Conventional angle-tuned thin-film filters have serious angle sensitivity for their low spacer effective refractive index, and it is difficult to fabricate their angle control system. In this paper, we propose and fabricate a novel 100 GHz angletuned thin-film filter stack with low angle sensitivity, which uses the high refractive index material TiO2 as the spacer, and its incident angle can be expanded to 25°. Compared with the traditional Ta2O5-SiO2 thin-film filter stack, the novel stack has fewer layers. Using the polarization beam splitters and the half wave plates, the polarization sensitivity of the angle-tuned filter can also be suppressed. Simulation results and the experiments show that the thin-film filter with low angle sensitivity has an effective tuning range of 33 nm, which can cover the whole C-band, and its angle control system is easy to be fabricated.
Oblique Incidence / Polarization Beam Splitter / Half Wave Plate / Refractive Index Material / Measured Transmittance Spectrum
/
| 〈 |
|
〉 |