Related Experiment Video
Updated: Sep 27, 2025
08:39
Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator
Published on: January 28, 2019
9.9K
Switchable distributed Bragg reflector using GST phase change material
Optics Letters
|April 15, 2022
Summary
This study presents a switchable distributed Bragg reflector (DBR) using germanium and a phase change material. It achieves near-zero reflection in the OFF state and over 70% reflection in the ON state at 2 µm.
Area of Science:
- Optics and Photonics
- Materials Science
- Nanotechnology
Background:
- Distributed Bragg reflectors (DBRs) are crucial optical components.
- Achieving tunable reflectivity in DBRs remains a significant challenge.
- Phase-change materials offer unique optical switching capabilities.
Purpose of the Study:
- To design and fabricate a thermally switchable DBR.
- To achieve tunable reflectivity from near-zero to over 70%.
- To explore the use of germanium and Ge2Sb2Te5 in switchable optical devices.
Main Methods:
- Fabrication of a multilayer thin film stack using germanium (Ge) and Ge2Sb2Te5 (GST).
- Utilizing the refractive index difference between amorphous and crystalline GST states.
- Incorporating antireflection coatings for precise optical control.
Main Results:
- Demonstrated a switchable DBR with thermally controlled reflectivity.
- Achieved a near-zero reflection (OFF state) due to matched refractive indexes.
- Obtained over 70% reflection (ON state) by switching GST to its crystalline phase.
- Operated the switchable DBR at a wavelength of 2 µm.
Conclusions:
- Successfully designed and fabricated a switchable DBR using Ge and GST.
- The device exhibits significant tunable reflectivity based on GST phase transition.
- This technology holds promise for tunable optical filters and switches.
