57 research outputs found
Depolarized Holography with Polarization-multiplexing Metasurface
The evolution of computer-generated holography (CGH) algorithms has prompted
significant improvements in the performances of holographic displays.
Nonetheless, they start to encounter a limited degree of freedom in CGH
optimization and physical constraints stemming from the coherent nature of
holograms. To surpass the physical limitations, we consider polarization as a
new degree of freedom by utilizing a novel optical platform called metasurface.
Polarization-multiplexing metasurfaces enable incoherent-like behavior in
holographic displays due to the mutual incoherence of orthogonal polarization
states. We leverage this unique characteristic of a metasurface by integrating
it into a holographic display and exploiting polarization diversity to bring an
additional degree of freedom for CGH algorithms. To minimize the speckle noise
while maximizing the image quality, we devise a fully differentiable
optimization pipeline by taking into account the metasurface proxy model,
thereby jointly optimizing spatial light modulator phase patterns and geometric
parameters of metasurface nanostructures. We evaluate the metasurface-enabled
depolarized holography through simulations and experiments, demonstrating its
ability to reduce speckle noise and enhance image quality.Comment: 15 pages, 13 figures, to be published in SIGGRAPH Asia 202
Multi-kilowatt single-mode ytterbium-doped large-core fiber laser
We have demonstrated a highly efficient cladding-pumped ytterbium-doped fiber laser, generating >2.1 kW of continuous-wave output power at 1.1 µm with 74% slope efficiency with respect to launched pump power. The beam quality factor (M2) was better than 1.2. The maximum output power was only limited by available pump power, showing no evidence of roll-over even at the highest output power. We present data on how the beam quality depends on the fiber parameter, based on our current and past fiber laser developments. We also discuss the ultimate power-capability of our fiber in terms of thermal management, Raman nonlinear scattering, and material damage, and estimate it to 10 k
Realising high sensitivity at 40 Gbit/s and 100 Gbit/s
We experimentally investigate modulation formats for realizing high data rate and high power sensitivity using coherent reception with low noise-figure optical preamplification. 40 Gbit/s PS-QPSK exhibits a sensitivity of 4.3 photons/bit while 100 Gbit/s PDM-QPSK exhibits a sensitivity of 5.3 photons/bit at 3.8Ă—10-3 BER
Focus issue introduction: Advanced Solid-State Lasers (ASSL) 2014
The editors introduce the focus issue on Advanced Solid-State Lasers (ASSL) 2014, which is based on the topics presented at a congress of the same name held in Shanghai, China, from October 27 to November 1, 2014. This Focus issue, jointly prepared by Optics Express and Optical Materials Express, includes 28 contributed papers (21 for Optics Express and 7 for Optical Materials Express) selected from the voluntary submissions by attendees who presented at the congress and have extended their work into complete research articles. We hope this focus issue offers a useful snapshot of the variety of topical discussions held at the congress and will contribute to the further expansion of the associated research areas
Theoretical and numerical study of cylindrical-vector-mode radiation characteristics in periodic metallic annular slits and their applications
We investigate the radiation characteristics of radially polarized light and azimuthally polarized light through plasmonic subwavelength-scale annular slit (PSAS) structures, by means of both theoretical and numerical methods. Effective-medium theory was utilized to analyze the characteristics of PSAS structures, and the corresponding results showed that PSAS structures can function as a metallic medium for azimuthally polarized light, or as a low-loss dielectric medium for radially polarized light. Numerical calculations based on the finite-element method were also performed, to verify the theoretical analyses. It turned out that the numerical results supported the theoretical results. Moreover, we exploited the PSAS structures in novel nanophotonic elements with dual functionalities that could selectively focus or pass/block incident light, depending on its polarization state. For example, if PSAS structures were implemented in the dielectric region of a metallic Fresnel zone plate, the modified zone plate could function as a blocking element to azimuthally polarized light, yet as a focusing element to radially polarized light. On the contrary, if PSAS structures were implemented in the metallic region of a metallic Fresnel zone plate (i.e. the inverted form of the former), it could function as a focusing element to azimuthally polarized light, yet as a simple transparent element to radially polarized light
Visualization 1
Dark-field optical microscope images of the transmitted light at different image planes and for different incident polarization states
Soliton Spectrum and Kelly Side Bands.bmp
Progression of the optical spectrum of the breathing MS regime with respect to time: Tn denotes that the typical time when the breathing MS regime is in State n
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