US 6,097,870 A · Article utilizing optical waveguides with anomalous dispersion at vis-nir wavelenghts

Abstract

Properly designed optical waveguides exhibit anomalous (positive) dispersion over a continuum of visible and near infrared wavelengths and, in one embodiment, the fiber has zero-dispersion at a visible wavelength (e.g., about 760 nm). Preferably, the zero-dispersion point occurs at a vis-nir wavelength where the normal (negative) material dispersion is relatively high and the effective refractive index difference between the core and the cladding is sufficiently large that the anomalous (positive) waveguide dispersion compensates the normal material dispersion. Illustratively, the optical waveguide is a microstructured fiber comprising a solid silica core surrounded by an inner cladding that includes a plurality of capillary air holes that allow for index-guiding within the core. The pattern formed by the cross-sections of the air holes, typically circles, may take on a variety geometric configurations, such as a closely packed hexagon or triangle. Alternatively, the cross-section of the air holes may form two mating, essentially semicircular regions on either side of a core that is supported by a pair of radial webs. As a result of the novel dispersion characteristics of the microstructured fibers combined with small effective area cores, we have demonstrated several applications of the invention that, in the prior art of standard single-mode fibers, have been possible only at wavelengths greater than about 1300 nm, including pulse compression, bright soliton propagation, fundamental mode-to-fundamental mode second harmonic generation, and broadband continuum generation in the visible.

Claims55

Dependent claims

A microstructured optical fiber comprising

a core region in which optical radiation can propagate,
an inner cladding region surrounding said core region and having an effective refractive index lower than that of said core region,
an outer cladding region surrounding said inner cladding region, characterized in that
said inner cladding region includes a multiplicity of features positioned circumferentially in at least one relatively thin layer around said core region, said features being effective to provide index guiding of said radiation, and said core region and said inner cladding region being mutually adapted so that said fiber exhibits anomalous group velocity dispersion over a range of vis-nir wavelengths and a zero-dispersion wavelength within the same range.

1 more element

An optical communication system comprising

a transmitter for generating an optical signal,
a receiver adapted to receive said signal,
a transmission medium for coupling said signal from said transmitter to said receiver, said medium including a section of optical waveguide,
characterized in that said waveguide comprises
a core region in which said signal propagates,
a cladding region adjacent said core region, the effective area of said core region and the difference in effective refractive index between said core region and said cladding region being mutually adapted so that said waveguide exhibits anomalous group velocity dispersion over a range of vis-nir wavelengths and a zero-dispersion wavelength within the same range, and
further characterized in that said transmitter generates a optical signal at a vis-nir wavelength within said range.

4 more elements

An optical system comprising

a laser that generates optical pulses,
a single mode optical waveguide to receive said pulses,
characterized in that said waveguide comprises
a core region in which said pulses propagate,
a cladding region adjacent said core region, the effective area of said core region and the difference in effective refractive index between said core region and said cladding region being mutually adapted so that said waveguide exhibits anomalous group velocity dispersion over a range of vis-nir wavelengths and a zero-dispersion wavelength within the same range, and
further characterized in that said laser generates said pulses at a vis-nir wavelength within said range, thereby to compress said pulses.

3 more elements

An optical generator of radiation at vis-nir wavelengths comprising

an optical pump source for generating a pump signal,
an optical waveguide adapted to receive said pump signal,
characterized in that said waveguide comprises
a core region in which said pump signal propagates,
a cladding region adjacent said core region, the effective area of said core region and the difference in effective refractive index between said core region and said cladding region being mutually adapted so that said waveguide exhibits anomalous group velocity dispersion over a range of vis-nir wavelengths and a zero-dispersion wavelength within the same range, and
further characterized in that said pump signal has a wavelength .lambda..sub.p in said vis-nir range, thereby to cause said waveguide to generate said radiation as a broadband continuum at vis-nir wavelengths.

3 more elements

An optical generator of radiation at vis-nir wavelengths comprising

an optical pump source for generating a fundamental transverse mode pump signal,
an optical waveguide adapted to receive said pump signal,
characterized in that said waveguide comprises
a core region in which said pump signal propagates,
a cladding region adjacent said core region, the effective area of said core region and the difference in effective refractive index between said core region and said cladding region being mutually adapted so that said waveguide exhibits anomalous group velocity dispersion over a range of vis-nir wavelengths and a zero-dispersion wavelength within the same range, and
further characterized in that said pump signal has a wavelength .lambda..sub.p in said vis-nir range, thereby to cause said waveguide to generate said radiation in a fundamental transverse mode and at a vis-nir wavelength less than said pump wavelength.

3 more elements

Dependencies are inferred from the claim text.

Article utilizing optical waveguides with anomalous dispersion at vis-nir wavelenghts

Life of this patent

Article utilizing optical waveguides with anomalous dispersion at vis-nir wavelenghts

Life of this patent

Abstract

Claims55