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Proceedings ArticleDOI

Modal decomposition of optical fiber output in OAM basis using optical correlation technique

TL;DR: In this paper, the optical fiber output beam was represented as linear superposition of orbital angular momentum (OAM) modes to quantify its purity, and good agreement between the experimentally measured OAM and simulated spectrum was observed.
Abstract: We represent the optical fiber output beam as linear superposition of orbital angular momentum (OAM) modes to quantify its purity. Through controlled experiments, we observe good agreement between the experimentally measured OAM and simulated spectrum.
References
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Journal ArticleDOI
28 Jun 2013-Science
TL;DR: The viability of using the orbital angular momentum (OAM) of light to create orthogonal, spatially distinct streams of data-transmitting channels that are multiplexed in a single fiber is demonstrated and suggest that OAM could provide an additional degree of freedom for data multiplexing in future fiber networks.
Abstract: Internet data traffic capacity is rapidly reaching limits imposed by optical fiber nonlinear effects Having almost exhausted available degrees of freedom to orthogonally multiplex data, the possibility is now being explored of using spatial modes of fibers to enhance data capacity We demonstrate the viability of using the orbital angular momentum (OAM) of light to create orthogonal, spatially distinct streams of data-transmitting channels that are multiplexed in a single fiber Over 11 kilometers of a specially designed optical fiber that minimizes mode coupling, we achieved 400-gigabits-per-second data transmission using four angular momentum modes at a single wavelength, and 16 terabits per second using two OAM modes over 10 wavelengths These demonstrations suggest that OAM could provide an additional degree of freedom for data multiplexing in future fiber networks

2,343 citations

Journal ArticleDOI
TL;DR: It is outlined how virtually all the previous ISO-standard beam diagnostic techniques may be readily replaced with all-digital equivalents, thus paving the way for unravelling of light in real time.
Abstract: Modal decomposition of light has been known for a long time, applied mostly to pattern recognition. With the commercialization of liquid-crystal devices, digital holography as an enabling tool has become accessible to all, and with it all-digital tools for the decomposition of light have finally come of age. We review recent advances in unravelling the properties of light, from the modal structure of laser beams to decoding the information stored in orbital angular momentum (OAM)-carrying fields. We show application of these tools to fiber lasers, solid-state lasers, and structured light created in the laboratory by holographic laser beam shaping. We show by experimental implementation how digital holograms may be used to infer the intensity, phase, wavefront, Poynting vector, polarization, and OAM density of some unknown optical field. In particular, we outline how virtually all the previous ISO-standard beam diagnostic techniques may be readily replaced with all-digital equivalents, thus paving the way for unravelling of light in real time. Such tools are highly relevant to the in situ analysis of laser systems, to mode division multiplexing as an emerging tool in optical communication, and for quantum information processing with entangled photons.

503 citations

Journal ArticleDOI
TL;DR: Two holograms of this class of phase computer-generated holograms for the encoding of arbitrary scalar complex fields are described that allow high quality reconstruction of the encoded field even if they are implemented with a low-resolution pixelated phase modulator.
Abstract: We discuss a class of phase computer-generated holograms for the encoding of arbitrary scalar complex fields. We describe two holograms of this class that allow high quality reconstruction of the encoded field, even if they are implemented with a low-resolution pixelated phase modulator. In addition, we show that one of these holograms can be appropriately implemented with a phase modulator limited by a reduced phase depth.

416 citations

Journal ArticleDOI
TL;DR: Novel results are presented for the complete modal decomposition of optical fields by using computer-generated holographic filters and the suitability of this method is proven by reconstructing various fields emerging from a weakly multi-mode fiber with arbitrary mode contents.
Abstract: The description of optical fields in terms of their eigenmodes is an intuitive approach for beam characterization. However, there is a lack of unambiguous, pure experimental methods in contrast to numerical phase-retrieval routines, mainly because of the difficulty to characterize the phase structure properly, e.g. if it contains singularities. This paper presents novel results for the complete modal decomposition of optical fields by using computer-generated holographic filters. The suitability of this method is proven by reconstructing various fields emerging from a weakly multi-mode fiber (V ≈ 5) with arbitrary mode contents. Advantages of this approach are its mathematical uniqueness and its experimental simplicity. The method constitutes a promising technique for real-time beam characterization, even for singular beam profiles.

250 citations

Journal ArticleDOI
TL;DR: A new (to the authors' knowledge) method to determine the modal content of the fiber is proposed and high purity of the desired vortex state is demonstrated (97% after 20 m, even after bends and twists).
Abstract: We present a fiber-based method for generating vortex beams with a tunable value of orbital angular momentum from −1ℏ to +1ℏ per photon. We propose a new (to our knowledge) method to determine the modal content of the fiber and demonstrate high purity of the desired vortex state (97% after 20 m, even after bends and twists). This method has immediate utility for the multitude of applications in science and technology that exploit vortex light states.

229 citations