Coherent Beam Combining Using an Internally Sensed Optical Phased Array of Frequency-Offset Phase Locked Lasers

Photonics

LyleE. Roberts¹  DanielA. Shaddock¹  RobertL. Ward¹  Craig Smith² 

[1] Centre for Gravitational Astrophysics, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia;EOS Space Systems Pty Ltd., Queanbeyan, NSW 2620, Australia;

关键词: optical phased arrays;    coherent beam combining;    frequency-offset phase locking;   

DOI  :  10.3390/photonics7040118

来源: DOAJ

【 摘 要 】

Coherent beam combining can be used to scale optical power and enable mechanism-free beam steering using an optical phased array. Coherently combining multiple free-running lasers in a leader-follower laser configuration is challenging due to the need to measure and stabilize large and highly dynamic phase differences between them. We present a scalable technique based on frequency-offset phase locking and digitally enhanced interferometry to clone the coherence of multiple lasers without the use of external sampling optics, which has the potential to support both coherent and spectral beam combining, and alleviates issues of voltage wrapping associated with actuating feedback control using electro-optic modulators. This technique was demonstrated experimentally using a tiled-aperture optical phased array in which the relative output phase of three free-running lasers was stabilized with an RMS output phase stability of $\lambda /104$.

【 授权许可】

Unknown