Abstract: A substantially dispersion-free optical filter cavity includes a first multilayer mirror and a second multilayer mirror, wherein each mirror includes layers of a less-refractive material and layers of a more-refractive material, the more-refractive material having a higher index of refraction than the less-refractive material. The mirrors are separated by a spacing, and the thickness of a plurality of the layers in the second multilayer mirror differ from corresponding layers in the first multilayer mirror to provide the cavity with complementary group-delay dispersion across the cavity with a phase difference within, e.g., ±0.015 rad across a range of wavelengths spanning at least, e.g., 50 nm.

Abstract: A laser cavity includes a gain medium for amplifying a light pulse in a light path, wherein the gain medium has a gain profile for amplifying the light pulse as a function of wavelength; at least one mirror on one side of the gain medium; and an output coupler. The output coupler has an output coupling profile for inducing loss in the light pulse as a function of wavelength that substantially matches the saturated gain profile of the gain medium across a range of lasing wavelengths. The purpose of this device is to achieve a flattened net-gain profile to substantially improve mode-locking performance with respect to self-starting, beam-quality, and broadband operation.

Abstract: A laser cavity includes a gain medium for amplifying a light pulse in a light path, wherein the gain medium has a gain profile for amplifying the light pulse as a function of wavelength; at least one mirror on one side of the gain medium; and an output coupler. The output coupler has an output coupling profile for inducing loss in the light pulse as a function of wavelength that substantially matches the saturated gain profile of the gain medium across a range of lasing wavelengths. The purpose of this device is to achieve a flattened net-gain profile to substantially improve mode-locking performance with respect to self-starting, beam-quality, and broadband operation.

Abstract: A substantially dispersion-free optical filter cavity includes a first multilayer mirror and a second multilayer mirror, wherein each mirror includes layers of a less-refractive material and layers of a more-refractive material, the more-refractive material having a higher index of refraction than the less-refractive material. The mirrors are separated by a spacing, and the thickness of a plurality of the layers in the second multilayer mirror differ from corresponding layers in the first multilayer mirror to provide the cavity with complementary group-delay dispersion across the cavity with a phase difference within, e.g., ±0.015 rad across a range of wavelengths spanning at least, e.g., 50 nm.

Abstract: The invention discloses a plastic waveguide for guiding terahertz (THz) wave with a wavelength ranging from 30 to 3000 ?m. The plastic waveguide includes a core and a cladding layer. At least part of the core is made of a first plastic medium having a first refractive index, and the maximum length of a cross-section of the core is smaller than the wavelength of the guided terahertz wave. The cladding layer surrounds the core and has a second refractive index lower than the first refractive index. In the invention, only one wave mode is propagated in the plastic waveguide, and a first attenuation constant of the core for the guided terahertz wave is higher than a second attenuation constant of the cladding layer for the guided terahertz wave.

Abstract: The invention discloses a plastic waveguide for guiding terahertz (THz) wave with a wavelength ranging from 30 to 3000 ?m. The plastic waveguide includes a core and a cladding layer. At least part of the core is made of a first plastic medium having a first refractive index, and the maximum length of a cross-section of the core is smaller than the wavelength of the guided terahertz wave. The cladding layer surrounds the core and has a second refractive index lower than the first refractive index. In the invention, only one wave mode is propagated in the plastic waveguide, and a first attenuation constant of the core for the guided terahertz wave is higher than a second attenuation constant of the cladding layer for the guided terahertz wave.