Abstract:
An optical sensor, a method of configuring an optical sensor, and a method of using an optical sensor are provided. The optical sensor includes an optical waveguide having a length and a laser source optically coupled to the waveguide. The laser source has a coherence length. Light from the source is transmitted to the waveguide as a first signal propagating along the waveguide in a first direction and a second signal propagating along the waveguide in a second direction opposite to the first direction. The optical paths of the first signal and the second signal are substantially reciprocal with one another and the first signal and the second signal are combined together after propagating through the waveguide to generate a third signal. The coherence length is greater than 1 meter or is in a range between 200 microns and 10 centimeters.
Abstract:
An optical device and methods of using an optical device are provided. The optical device includes a hollow-core fiber including a first portion and a second portion. The first portion includes a hollow core having a first diameter. The second portion includes a hollow core having a second diameter smaller than the first diameter. The difference between the first diameter and the second diameter is less than 10% of the first diameter.
Abstract:
An optical sensor includes at least one optical coupler and an optical waveguide in optical communication with the at least one optical coupler. The optical waveguide is configured to receive a first optical signal from the at least one optical coupler. The first optical signal has a group velocity and a phase velocity while propagating through at least a portion of the optical waveguide, the group velocity less than the phase velocity. An interference between the first optical signal and a second optical signal is affected by relative movement between the optical waveguide and the at least one optical coupler.
Abstract:
An optical device and methods of using an optical device are provided. The optical device includes a hollow-core fiber including a first portion and a second portion. The first portion includes a hollow core having a first diameter. The second portion includes a hollow core having a second diameter smaller than the first diameter. The difference between the first diameter and the second diameter is less than 10% of the first diameter.
Abstract:
A doped superfluorescent fiber source (SFS) has an enhanced mean wavelength stability. A method stabilizes the mean wavelength of a SFS. The method includes pumping the SFS with pump light from a pump source having a wavelength dependent on the temperature of the pump source and dependent on the power of the pump light. The length of the fiber is selected to compromise between reduction of the dependence of the mean wavelength on the pump light power and reduction of the contribution of the forward amplified spantaneous emission light produced by the fiber to the output light.
Abstract:
An optical fiber includes a cladding with a material having a first refractive index and a pattern of regions formed therein. Each of the regions has a second refractive index lower than the first refractive index. The optical fiber further includes a core region and a core ring having an inner perimeter, an outer perimeter, and a thickness between the inner perimeter and the outer perimeter. The thickness is sized to reduce the number of ring surface modes supported by the core ring.
Abstract:
A method for measuring a physical function forms a symmetric composite function by combining the physical function with a reference function. The method obtains a Fourier transform of the symmetric composite function. The method calculates an inverse Fourier transform of the obtained Fourier transform, wherein the calculated inverse Fourier transform provides information regarding the physical function. The physical function can be a nonlinearity profile of a sample with at least one sample surface. The physical function can alternatively by a sample temporal waveform of a sample optical pulse.
Abstract:
An optical sensor, a method of configuring an optical sensor, and a method of using an optical sensor are provided. The optical sensor includes an optical waveguide having a length and a laser source optically coupled to the waveguide. The laser source has a coherence length. Light from the source is transmitted to the waveguide as a first signal propagating along the waveguide in a first direction and a second signal propagating along the waveguide in a second direction opposite to the first direction. The optical paths of the first signal and the second signal are substantially reciprocal with one another and the first signal and the second signal are combined together after propagating through the waveguide to generate a third signal. The coherence length is greater than 1 meter or is in a range between 200 microns and 10 centimeters.
Abstract:
A method utilizes an optical image processing system. The method includes calculating a product of (i) a measured magnitude of a Fourier transform of a complex transmission function of an object or optical image and (ii) an estimated phase term of the Fourier transform of the complex transmission function. The method further includes calculating an inverse Fourier transform of the product, wherein the inverse Fourier transform is a spatial function. The method further includes calculating an estimated complex transmission function by applying at least one constraint to the inverse Fourier transform.
Abstract:
An optical sensor includes at least a portion of an optical waveguide having a hollow core generally surrounded by a cladding. The cladding substantially confines a first optical signal and a second optical signal within the hollow core as the first optical signal and the second optical signal counterpropagate through the optical waveguide. Interference between the first optical signal and the second optical signal is responsive to perturbation of the at least a portion of the optical waveguide.