Search results for "Mode volume"
showing 10 items of 30 documents
Analytical design of 160 Gbits/s densely dispersion-managed optical fiber transmission systems using Gaussian and raised cosine RZ ansätze
2004
We present an easy and efficient analytical method to design 160 Gbits/s densely dispersion-managed optical fiber transmission systems using Gaussian and raised cosine RZ ansatze.
Polarization mode dispersion and vectorial modulational instability in air silica microstructure fiber
2002
The birefringence of an air-silica microstructure fiber has been studied by measurement of the fiber polarization mode dispersion (PMD) over the wavelength range 545-640 nm. The experimental results are shown to be in good agreement with vectorial numerical calculations, assuming an elliptical core with an eccentricity of 7%. We also report controlled experiments studying nonlinear vectorial modulation instability in the fiber, yielding 3.9-THz modulational instability sideband shifts that are in good agreement with theoretical predictions based on the calculated fiber dispersion and PMD characteristics.
Wavelength-multiplexing system for single-mode image transmission
1997
The expanding use of optical communication by means of optical fibers and the situation of drastically increasing amounts of data to be transmitted urge the exploration of novel systems permitting the transmission of large amounts of spatial information by fiber with smaller spatial resolution. An optical encoding and decoding system is suggested for transmitting one- or two-dimensional images by means of a single-mode fiber. The superresolving system is based on wavelength multiplexing of the input spatial information, which is achieved with diffractive optical elements. Preliminary experimental results demonstrate the capabilities of the suggested method for the one- and two-dimensional c…
Hybrid surface plasma modes in circular metal-coated tapered fibers
1999
The theory of hybrid surface plasma modes in metal-coated dielectric cylinders has been developed in recent years. We demonstrate that tapered fibers with a uniform waist and a circular metal coating can be designed for an efficient excitation of the fundamental hybrid surface plasma mode. Our experimental results are in good agreement with the theory and give the basis for the development of a novel type of all-fiber polarization-independent refractive-index sensor and tunable broadband wavelength filter.
Actively mode-locked fiber ring laser by intermodal acousto-optic modulation
2010
We report an actively mode-locked fiber ring laser. A simple and low-insertion-loss acousto-optic modulator driven by standing flexural waves, which couples core-to-cladding modes in a standard single-mode optical fiber, is used as an active mechanism for mode locking. Among the remarkable features of the modulator, we mention its high modulation depth (72%), broad bandwidth (187 GHz), easy tunability in the optical wavelength, and low insertion losses (0.7 dB). The narrowest optical pulses obtained were of 95 ps time width, 21 mW peak power, repetition rate of 4.758 MHz, and 110 mW of pump power.
Excitation and interrogation of whispering-gallery modes in optical microresonators using a single fused-tapered fiber tip
2011
We show that whispering-gallery modes (WGMs) in optical microresonators can be excited and detected using a fused-tapered fiber tip (FTFT). The fabrication of FTFTs is simple and inexpensive; they are robust and allow the excitation and interrogation of the resonances with a single fiber. Excitation of high-Q WGMs in silica microcylinders and microspheres is demonstrated.
Characterization of fiber nonuniformities with ppm resolution using time-resolved in-fiber acousto-optics
2014
Time-resolved acousto-optic interaction using flexural waves enables the characterization of fiber nonuniformities along sections of about 1-2 m. A resolution better than 10 ppm of fiber diameter and core refractive index is demonstrated.
Design and optimization of broadband tapered optical fibers with a nanofiber waist
2010
The control over the transmission properties of tapered optical fibers (TOFs) is an important requirement for a whole range of applications. Using a carefully designed flame pulling process that allows us to realize preset fiber radius profiles, we fabricate TOFs with a nanofiber waist. We study the spectral transmission properties of these TOFs as a function of the taper profile and the waist length and show how the transmission band of the TOF can be tuned via different fiber profile parameters. Based on these results, we have designed a nanofiber-waist TOF with broadband transmission for surface spectroscopy of organic molecules. Moreover, our method allows us to analyze the loss mechani…
Accurate modal characterization of optical fibers using acousto-optics
2016
In-fiber acousto-optics enable accurate and broadband characterization of two mode optical fibers. Differential effective index, group index and dispersion are reported for two-mode optical fibers. Small phase differences between the quasi-degenerated vector modes comprising the LP 11 mode are also measured. In addition, a fine analysis of fiber axial non-uniformities can be performed using a time-resolved acousto-optic technique. In this case, sub-ppm changes of effective index are measured with few cm resolution along fiber sections of about 2 m.
Endlessly single-mode heat-sink waveguide
1998
Recently, a new form of optical fiber, the photonic crystal fiber, has been reported. This fiber has a hexagonal array of submicrometer air holes running along its length and a lattice site without a hole (a line defect) in its center. The defect acts as a core, confining light that travels along the fiber as a guided mode. This structure can be endlessly single mode, never supporting more than one confined mode no matter what the diameter of the core or the wavelength of the light. Having discovered this effect experimentally and provided a qualitative explanation for the observed behavior, we present here a planar version of this fiber. Periodic arrays of parallel planar fins are placed o…