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Journal Article
Design Method of Tunable Pixel with Phase-Change Material for Diffractive Optical Elements
- Authors
- Seung-Yeol Lee, Han Na Kim, Yong Hae Kim, Tae-Youb Kim, Seong-Mok Cho, Han Byeol Kang, Chi-Sun Hwang
- Issue Date
- 2017-06
- Citation
- ETRI Journal, v.39, no.3, pp.390-397
- ISSN
- 1225-6463
- Publisher
- 한국전자통신연구원 (ETRI)
- Language
- English
- Type
- Journal Article
- Abstract
- 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 Keywords
- 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