142,993 research outputs found
Dual-band ridged waveguide
Waveguide-in-waveguide technique involves routing two waveguides through same passageway. Smaller waveguide can be soft or silver soldered inside X-band waveguide to form single ridge guide and to propagate frequencies at C-band
A Directly-Written Monolithic Waveguide-Laser Incorporating a DFB Waveguide-Bragg Grating
We report the fabrication and performance of the first C-band
directly-written monolithic waveguide-laser. The waveguide-laser device was
created in an Erbium and Ytterbium doped phosphate glass host and consisted of
an optical waveguide that included a distributed feedback Bragg grating
structure. The femtosecond laser direct-write technique was used to create both
the waveguide and the waveguide-Bragg grating simultaneously and in a single
processing step. The waveguide-laser was optically pumped at approximately 980
nm and lased at 1537nm with a bandwidth of less than 4 pm.Comment: 6 pages, 13 references, 4 figure
Waveguide cooling system
An improved system is described for cooling high power waveguides by the use of cooling ducts extending along the waveguide, which minimizes hot spots at the flanges where waveguide sections are connected together. The cooling duct extends along substantially the full length of the waveguide section, and each flange at the end of the section has a through hole with an inner end connected to the duct and an opposite end that can be aligned with a flange hole in another waveguide section. Earth flange is formed with a drainage groove in its face, between the through hole and the waveguide conduit to prevent leakage of cooling fluid into the waveguide. The ducts have narrowed sections immediately adjacent to the flanges to provide room for the installation of fasteners closely around the waveguide channel
Ion-Exchanged Glass Waveguide Technology: A Review
We review the history and current status of ion exchanged glass waveguide technology. The background of ion exchange in glass and key developments in the first years of research are briefly described. An overview of fabrication, characterization and modeling of waveguides is given and the most important waveguide devices and their applications are discussed. Ion exchanged waveguide technology has served as an available platform for studies of general waveguide properties, integrated optics structures and devices, as well as applications. It is also a commercial fabrication technology for both passive and active waveguide components
Exciton-polariton emission from organic semiconductor optical waveguides
We photo-excite slab polymer waveguides doped with J-aggregating dye
molecules and measure the leaky emission from strongly coupled waveguide
exciton polariton modes at room temperature. We show that the momentum of the
waveguide exciton polaritons can be controlled by modifying the thickness of
the excitonic waveguide. Non-resonantly pumped excitons in the slab excitonic
waveguide decay into transverse electric and transverse magnetic strongly
coupled exciton waveguide modes with radial symmetry. These leak to cones of
light with radial and azimuthal polarizations
Entangling two distant nanocavities via a waveguide
In this paper, we investigate the generation of continuous variable
entanglement between two spatially-separate nanocavities mediated by a coupled
resonator optical waveguide in photonic crystals. By solving the exact dynamics
of the cavity system coupled to the waveguide, the entanglement and purity of
the two-mode cavity state are discussed in detail for the initially separated
squeezing inputs. It is found that the stable and pure entangled state of the
two distant nanocavities can be achieved with the requirement of only a weak
cavity-waveguide coupling when the cavities are resonant with the band center
of the waveguide. The strong couplings between the cavities and the waveguide
lead to the entanglement sudden death and sudden birth. When the frequencies of
the cavities lie outside the band of the waveguide, the waveguide-induced cross
frequency shift between the cavities can optimize the achievable entanglement.
It is also shown that the entanglement can be easily manipulated through the
changes of the cavity frequencies within the waveguide band.Comment: 8 pages, 8 figure
Substrate Integrated Bragg Waveguide: an Octave-bandwidth Single-mode Functional Transmission-Line for Millimeter-Wave and Terahertz Applications
We demonstrate an air-core single-mode hollow waveguide that uses Bragg
reflector structures in place of the vertical metal walls of the standard
rectangular waveguide or via holes of the so-called substrate integrated
waveguide. The high-order modes in the waveguide are substantially suppressed
by a modal-filtering effect, making the waveguide operate in the fundamental
mode over more than one octave. Numerical simulations show that the propagation
loss of the proposed waveguide can be lower than that of classic hollow
metallic rectangular waveguides at terahertz frequencies, benefiting from a
significant reduction in Ohmic loss. To facilitate fabrication and
characterization, a proof-of-concept 20 to 45 GHz waveguide is demonstrated,
which verifies the properties and advantages of the proposed waveguide. A zero
group-velocity dispersion point is observed at near the middle of the operating
band. This work offers a step towards a novel hybrid transmission-line medium
that can be used in a variety of functional components for broadband
millimeter-wave and terahertz applications.Comment: 11 pages, 9 figures, journal articl
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