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Diffractive optics for combined spatial- and mode- division demultiplexing of optical vortices: design, fabrication and optical characterization.

Ruffato G, Massari M, Romanato F - Sci Rep (2016)

Bottom Line: During the last decade, the orbital angular momentum (OAM) of light has attracted growing interest as a new degree of freedom for signal channel multiplexing in order to increase the information transmission capacity in today's optical networks.Here we present the design, fabrication and characterization of phase-only diffractive optical elements (DOE) performing mode-division (de)multiplexing (MDM) and spatial-division (de)multiplexing (SDM) at the same time.These novel DOE designs appear promising for telecom applications both in free-space and in multi-core fibers propagation.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics and Astronomy 'G. Galilei', University of Padova, via Marzolo 8, 35131 Padova, Italy.

ABSTRACT
During the last decade, the orbital angular momentum (OAM) of light has attracted growing interest as a new degree of freedom for signal channel multiplexing in order to increase the information transmission capacity in today's optical networks. Here we present the design, fabrication and characterization of phase-only diffractive optical elements (DOE) performing mode-division (de)multiplexing (MDM) and spatial-division (de)multiplexing (SDM) at the same time. Samples have been fabricated with high-resolution electron-beam lithography patterning a polymethylmethacrylate (PMMA) resist layer spun over a glass substrate. Different DOE designs are presented for the sorting of optical vortices differing in either OAM content or beam size in the optical regime, with different steering geometries in far-field. These novel DOE designs appear promising for telecom applications both in free-space and in multi-core fibers propagation.

No MeSH data available.


Related in: MedlinePlus

Scheme of the optical characterization setup.Laser source (λ = 632.8 nm), linear polarizer (P), LCoS spatial light modulator (SLM), first lens (L1), beam splitter (BS), diffractive optical element (DOE) mounted on XY micrometric translator, second lens (L2), cameras for analysis of the DOE input and output signals (CCD1, CCD2).
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f7: Scheme of the optical characterization setup.Laser source (λ = 632.8 nm), linear polarizer (P), LCoS spatial light modulator (SLM), first lens (L1), beam splitter (BS), diffractive optical element (DOE) mounted on XY micrometric translator, second lens (L2), cameras for analysis of the DOE input and output signals (CCD1, CCD2).

Mentions: The characterization setup was mounted on an optical table (see scheme in Fig. 7). The Gaussian beam (λ = 632.8 nm, beam waist w0 = 240 μm) emitted by a HeNe laser source illuminates the display of a reflective liquid-crystal-on-silicon (LCoS) spatial light modulator (PLUTO-NIR-010-A, Holoeye) for perfect vortex generation. Then the beam is collimated with a first lens of focal length f1 = 25 cm and a beam-splitter is placed in order to allow analyzing the field profile and its OAM content at the same time. The beam illuminates the DOE sample, fixed on a XY translation mount with micrometric drives and the far-field is collected at the back-focal plane of a lens of focal length f2 = 10 cm.


Diffractive optics for combined spatial- and mode- division demultiplexing of optical vortices: design, fabrication and optical characterization.

Ruffato G, Massari M, Romanato F - Sci Rep (2016)

Scheme of the optical characterization setup.Laser source (λ = 632.8 nm), linear polarizer (P), LCoS spatial light modulator (SLM), first lens (L1), beam splitter (BS), diffractive optical element (DOE) mounted on XY micrometric translator, second lens (L2), cameras for analysis of the DOE input and output signals (CCD1, CCD2).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837364&req=5

f7: Scheme of the optical characterization setup.Laser source (λ = 632.8 nm), linear polarizer (P), LCoS spatial light modulator (SLM), first lens (L1), beam splitter (BS), diffractive optical element (DOE) mounted on XY micrometric translator, second lens (L2), cameras for analysis of the DOE input and output signals (CCD1, CCD2).
Mentions: The characterization setup was mounted on an optical table (see scheme in Fig. 7). The Gaussian beam (λ = 632.8 nm, beam waist w0 = 240 μm) emitted by a HeNe laser source illuminates the display of a reflective liquid-crystal-on-silicon (LCoS) spatial light modulator (PLUTO-NIR-010-A, Holoeye) for perfect vortex generation. Then the beam is collimated with a first lens of focal length f1 = 25 cm and a beam-splitter is placed in order to allow analyzing the field profile and its OAM content at the same time. The beam illuminates the DOE sample, fixed on a XY translation mount with micrometric drives and the far-field is collected at the back-focal plane of a lens of focal length f2 = 10 cm.

Bottom Line: During the last decade, the orbital angular momentum (OAM) of light has attracted growing interest as a new degree of freedom for signal channel multiplexing in order to increase the information transmission capacity in today's optical networks.Here we present the design, fabrication and characterization of phase-only diffractive optical elements (DOE) performing mode-division (de)multiplexing (MDM) and spatial-division (de)multiplexing (SDM) at the same time.These novel DOE designs appear promising for telecom applications both in free-space and in multi-core fibers propagation.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics and Astronomy 'G. Galilei', University of Padova, via Marzolo 8, 35131 Padova, Italy.

ABSTRACT
During the last decade, the orbital angular momentum (OAM) of light has attracted growing interest as a new degree of freedom for signal channel multiplexing in order to increase the information transmission capacity in today's optical networks. Here we present the design, fabrication and characterization of phase-only diffractive optical elements (DOE) performing mode-division (de)multiplexing (MDM) and spatial-division (de)multiplexing (SDM) at the same time. Samples have been fabricated with high-resolution electron-beam lithography patterning a polymethylmethacrylate (PMMA) resist layer spun over a glass substrate. Different DOE designs are presented for the sorting of optical vortices differing in either OAM content or beam size in the optical regime, with different steering geometries in far-field. These novel DOE designs appear promising for telecom applications both in free-space and in multi-core fibers propagation.

No MeSH data available.


Related in: MedlinePlus