摘要:
A system includes a laser configured to generate a pump beam at a pump wavelength. The system also includes a multi-media Raman resonator configured to receive the pump beam and generate an output beam. The multi-media Raman resonator includes multiple mirrors and multiple Raman media optically located between the minors. Output power in the output beam is spectrally concentrated around a single dominant wavelength that is longer than a pump wavelength. The longer wavelength of the output beam is associated with a combination of at least one Stokes shift associated with each of the individual Raman media. A filter could be configured to absorb light at a wavelength that is absorbed by one of the Raman media or to redirect light at the wavelength absorbed by one of the Raman media away from that Raman medium.
摘要:
An optical device includes an optical material comprising active dopant ions and absorber dopant ions spaced apart from the active dopant ions. The active dopant ions are provided to absorb a first radiation and convert a portion of the first radiation into sensible heat. A concentration profile of the absorber dopant ions is selected to absorb a second radiation different from the first radiation and optionally the first radiation in at least one direction of the optical material so as to control a refractive index profile in the at least one direction of the optical material. In another embodiment, a method of controlling a refractive index profile in an optical material includes exciting active dopant ions in the optical material with a first radiation, the active dopant ions converting at least a portion of the first radiation into sensible heat; and exciting absorber dopant ions in the optical material with a second radiation to control a refractive index profile in at least one direction of the optical material.
摘要:
A planar laser gain medium and laser system. The novel laser gain medium includes an active core having a high aspect ratio cross-section with a fast-axis dimension and a slow-axis dimension, signal claddings adapted to form reflective boundaries at fast-axis boundaries of the core, and a material adapted to minimize reflections at slow-axis boundaries of the core. In an illustrative embodiment, the laser gain medium is an optical fiber. The core and claddings form a waveguide adapted to control modes propagating in the fast-axis direction. When the laser gain medium is employed as a laser oscillator, a high reflectivity mirror and an outcoupler are positioned at opposite ends of the core to form a laser resonator adapted to control modes in the slow-axis direction.
摘要:
According to an embodiment of the disclosure, a Raman generator includes a Raman medium and one or more optical elements. The Raman medium is configured to receive a pump pulse at a first wavelength and shift at least a portion of the pump pulse energy or power into a Stokes-shifted pulse at a second wavelength. The one or more optical elements are configured to pass the pump pulse and the Stokes-shifted pulse multiple times through the Raman medium. Each pass of the pulses through the Raman medium follows a path. Each path is parallel or anti-parallel to the other paths.
摘要:
A planar laser gain medium and laser system. The novel laser gain medium includes an active core having a high aspect ratio cross-section with a fast-axis dimension and a slow-axis dimension, signal claddings adapted to form reflective boundaries at fast-axis boundaries of the core, and a material adapted to minimize reflections at slow-axis boundaries of the core. In an illustrative embodiment, the laser gain medium is an optical fiber. The core and claddings for a waveguide adapted to control modes propagating in the fast-axis direction. When the laser gain medium is employed as a laser oscillator, a high reflectivity mirror and an outcoupler are positioned at opposite ends of the core to form a laser resonator adapted to control modes in the slow-axis direction.
摘要:
In various embodiments, a semi-guiding optical fiber includes a core having a first refractive index and a high aspect ratio elongated cross-section along a slow axis direction. First and second signal claddings having a second refractive index sandwich the core. A third cladding having a third refractive index substantially surrounds at least side edges of the core. The first refractive index of the core, the third refractive index of the third cladding, and/or the second refractive index of the first and second signal claddings, are selected so as to maximize a differential loss between a lowest order mode propagating in the optical fiber and next order modes so as to discriminate in favor of the lowest order mode and against the next order modes. In another embodiment, a method for mode control in a semi-guiding medium includes controlling either the first refractive index of the core, the second refractive index of the first and second signal claddings, and/or the third refractive index of the third cladding, to maximize a differential loss between a lowest order mode propagating in the optical fiber and next order modes so as to discriminate in favor of the lowest order mode and against the next order modes.
摘要:
In various embodiments, an optical fiber includes a core having a relatively large area selected so as to raise a threshold of stimulated Raman scattering or stimulated Brillouin scattering, or both, the core having a high aspect ratio elongated cross-section and having a first refractive index. The core is narrower in a fast-axis direction and wider in a slow-axis direction, such that the fiber is mechanically flexible in the fast-axis direction and is mechanically rigid in the slow-axis direction.
摘要:
According to an embodiment of the disclosure, a Raman generator includes a Raman medium and one or more optical elements. The Raman medium is configured to receive a pump pulse at a first wavelength and shift at least a portion of the pump pulse energy or power into a Stokes-shifted pulse at a second wavelength. The one or more optical elements are configured to synchronize one or more subsequent passages of the Stokes-shifted pulse through the Raman medium with one or more subsequent pump pulses at the first wavelength. The synchronized passage of the Stokes-shifted pulse and one or more subsequent pump pulses through the Raman medium increases a power of the Stoke-shifted pulse.
摘要:
In various embodiments, an optical element, e.g., an optical fiber, may be configured to compensate for thermal lensing. For example, thermal lensing may be caused by light power dissipation within an optical fiber, which may include a fiber core that guides amplified light along the longitudinal dimension of the fiber core. Thermal lensing from a thermally induced change in material refractive index as a function of position along dimensions perpendicular to the fiber's longitudinal dimension may be at least partially compensated or offset when light is guided by the fiber core by a designed-in effective refractive index profile selected such that the designed-in material refractive index of the fiber core changes as a function of transverse position within the fiber core, or by selection of a favorable cross-sectional core shape in a plane perpendicular to the longitudinal dimension of the fiber core.
摘要:
A planar laser gain medium and laser system. The novel laser gain medium includes an active core having a high aspect ratio cross-section with a fast-axis dimension and a slow-axis dimension, signal claddings adapted to form reflective boundaries at fast-axis boundaries of the core, and a material adapted to minimize reflections at slow-axis boundaries of the core. In an illustrative embodiment, the laser gain medium is an optical fiber. The core and claddings form a waveguide adapted to control modes propagating in the fast-axis direction. When the laser gain medium is employed as a laser oscillator, a high reflectivity mirror and an outcoupler are positioned at opposite ends of the core to form a laser resonator adapted to control modes in the slow-axis direction.