Abstract
Acquiring precise information about the mode content of a laser is critical for multiplexed optical communications, optical imaging with active wave-front control, and quantum-limited interferometric measurements. Hologram-based mode decomposition devices, such as spatial light modulators, allow a fast, direct measurement of the mode content, but they have limited precision due to cross coupling between modes. Here, we report a proof-of-principle demonstration of mode decomposition with a metasurface, resulting in significantly enhanced precision. A mode-weight fluctuation of 6×10-7 was measured with 1 s of averaging at a Fourier frequency of 80 Hz, an improvement of more than three orders of magnitude compared to the state-of-the-art spatial light modulator decomposition. The improvement is attributable to the reduction in cross coupling enabled by the exceptionally small pixel size of the metasurface. We show a systematic study of the limiting sources of noise, and we show that there is a promising path towards complete mode decomposition with similar precision.
| Original language | English |
|---|---|
| Article number | 053523 |
| Pages (from-to) | 1-6 |
| Number of pages | 6 |
| Journal | Physical Review A |
| Volume | 105 |
| Issue number | 5 |
| Early online date | 26 May 2022 |
| DOIs | |
| Publication status | Published - May 2022 |
Bibliographical note
Funding Information:The authors jointly thank John Bryant and David Hoyland for developing the low-noise QPD and modifications to the EUCLID digitizer, used in precursor experiments. The authors thank Dr. Artemiy Dmitriev for developing control and data system (CDS) units at Birmingham. A.W.J. was supported by an EPSRC studentship No. 2161515 and ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), Project No. CE170100004.
Publisher Copyright:
© 2022 American Physical Society.
