양자 암호 키 분배를 위한 적응광학 시스템 변형 거울 성능 검증

초록

This study presents the performance of a deformable mirror (DM), a key component of the adaptive optics (AO) system, in the context of quantum key distribution (QKD) over free-space optical communications (FSOC). The potential of QKD, which offers theoretically unbreakable encryption by leveraging quantum mechanics, is immense for secure communication, particularly between ground stations and satellites. However, atmospheric turbulence significantly degrades the optical wavefront during FSO communication, leading to signal loss and increased error rates. To counteract these effects, AO systems use real-time wavefront correction via components such as a wavefront sensor, control system, and DM. In this work, the ALPAO DM308-15, featuring 308 actuators, was tested using a Zygo interferometer to evaluate its influence functions, linearity, hysteresis, best flat correction, and ability to reproduce Zernike modes. All influence functions of 308 actuators were precisely measured using a Zygo interferometer. The DM demonstrated excellent linearity with errors below 1.68% and negligible hysteresis. Best flat correction reduced the surface root-mean-square (RMS) error from 52 nm to 7.5 nm, a seven-fold improvement. This research has the potential to significantly impact the field of AO and quantum communication, inspiring new developments and applications. Furthermore, the mirror successfully reproduced 36 Zernike modes with a maximum RMS error deviation of only 8%, confirming its high spatial precision. Stability tests showed minimal degradation over 30 minutes, indicating its suitability for real-time AO operation. The DM not only met but exceeded performance requirements for FSO-QKD applications, providing a high level of precision, responsiveness, and stability. This reassures the audience of its reliable and consistent performance, instilling confidence in its potential for integration into next-generation AO systems aimed at secure satellite-to-ground quantum communication.

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