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arXiv · 1606.08551

Time-reversing a monochromatic subwavelength optical focus by optical phase conjugation of multiply-scattered light

Jongchan Park·Chunghyun Park·KyeoReh Lee·Yong-Hoon Cho·YongKeun Park
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Abstract

Due to its time-reversal nature, optical phase conjugation generates a monochromatic light wave which retraces its propagation paths. Here, we demonstrate the regeneration of a subwavelength optical focus by phase conjugation. Monochromatic light from a subwavelength source is scattered by random nanoparticles, and the scattered light is phase conjugated at the far-field region by coupling its wavefront into a single-mode optical reflector using a spatial light modulator. Then the conjugated beam retraces its propagation paths and forms a refocus on the source at the subwavelength scale. This is the first direct experimental realization of subwavelength focusing beyond the diffraction limit with far-field time reversal in the optical domain.

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Jongchan Park, Chunghyun Park, KyeoReh Lee, Yong-Hoon Cho, YongKeun Park. 2016-06-28. Time-reversing a monochromatic subwavelength optical focus by optical phase conjugation of multiply-scattered light. https://arxiv.org/abs/1606.08551

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