상세정보
학술지
Design Method of Tunable Pixel with Phase-Change Material for Diffractive Optical Elements
- 발행일
- 201706
- 출처
- ETRI Journal, v.39 no.3, pp.390-397
- ISSN
- 1225-6463
- 출판사
- 한국전자통신연구원 (ETRI)
- 초록
- In this paper, we propose a scheme for designing a tunable pixel layer based on a Ge2Sb2Te5 (GST) alloy thin film. We show that the phase change of GST can significantly affect the reflection characteristic when the GST film is embedded into a dielectric encapsulation layer. We investigate the appropriate positions of the GST film within the dielectric layer for high diffraction efficiency, and we prove that they are antinodes of Fabry-Perot resonance inside the dielectric layer. Using the proposed scheme, we can increase the diffraction efficiency by about ten times compared to a bare GST film pixel, and 80 times for the first-to-zeroth-order diffraction power ratio. We show that the proposed scheme can be designed alternatively for a broadband or wavelength-selective type by tuning the dielectric thickness, and we discuss a multiphase example with a double-stack structure.
- KSP 제안 키워드
- Alloy thin film, Design method, Dielectric thickness, Diffractive optical elements, Encapsulation layer, Fabry-Perot resonance, High diffraction efficiency, Phase Change Material(PCM), Reflection characteristics, Stack structure, dielectric layer