An all-fiber configuration system and method for generating temporally coherent supercontinuum pulsed emission are provided. The system includes a sequential structure of all-fiber sections including: a fiber laser seed source to produce a seed pulse with given optical properties; a stretching section including an optical fiber to temporally stretch the seed pulse; an amplification section including an active optical fiber, doped with a rare earth element, to amplify the stretched pulse by progressively stimulating radiation of active ions of the doped active optical fiber; a compressing section to temporally compress the amplified pulse; and a spectrum broadening section including an ANDi microstructured fiber that spectrally broadens the compressed pulse by a nonlinear effect of Self Phase Modulation (SPM) while maintaining the temporal coherence of the pulse.

A supercontinuum source may include a seed source providing seed light, where the seed source includes one or more seed lasers to generate the seed light and a seed controller to adjust at least one of a temporal pulse profile or a wavelength of the seed light. The supercontinuum source may further include an optical fiber to receive the seed light, where the seed source pumps the optical fiber to induce the generation of supercontinuum output light, and where a spectrum of the supercontinuum output light is controllable by adjusting at least one of the temporal pulse profile or the wavelength of the seed light with the seed controller.

A supercontinuum source may include a seed source providing seed light, where the seed source includes one or more seed lasers to generate the seed light and a seed controller to adjust at least one of a temporal pulse profile or a wavelength of the seed light. The supercontinuum source may further include an optical fiber to receive the seed light, where the seed source pumps the optical fiber to induce the generation of supercontinuum output light, and where a spectrum of the supercontinuum output light is controllable by adjusting at least one of the temporal pulse profile or the wavelength of the seed light with the seed controller.

A shaping encoder capable of improving the performance of PCS in nonlinear optical channels by performing the shaping in two or more stages. In an example embodiment, a first stage employs a shaping code of a relatively short block length, which is typically beneficial for nonlinear optical channels but may cause a significant penalty in the energy efficiency. A second stage then employs a shaping code of a much larger block length, which significantly reduces or erases the penalty associated with the short block length of the first stage while providing an additional benefit of good performance in substantially linear optical channels. In at least some embodiments, the shaping encoder may have relatively low circuit-implementation complexity and/or relatively low cost and provide relatively high energy efficiency and relatively high shaping gain for a variety of optical channels, including but not limited to the legacy dispersion-managed fiber-optic links.

A shaping encoder capable of improving the performance of PCS in nonlinear optical channels by performing the shaping in two or more stages. In an example embodiment, a first stage employs a shaping code of a relatively short block length, which is typically beneficial for nonlinear optical channels but may cause a significant penalty in the energy efficiency. A second stage then employs a shaping code of a much larger block length, which significantly reduces or erases the penalty associated with the short block length of the first stage while providing an additional benefit of good performance in substantially linear optical channels. In at least some embodiments, the shaping encoder may have relatively low circuit-implementation complexity and/or relatively low cost and provide relatively high energy efficiency and relatively high shaping gain for a variety of optical channels, including but not limited to the legacy dispersion-managed fiber-optic links.

A system and method for providing a radiation source. In one arrangement, the radiation source includes an optical fiber that is hollow, and has an axial direction, a gas that fills the hollow of the optical fiber, and a plurality of temperature setting devices disposed at respective positions along the axial direction of the optical fiber, wherein the temperature setting devices are configured to control the temperature of the gas to locally control the density of the gas.

In a wavelength conversion apparatus, reflection suppressors are provided on surfaces of optical elements indicating lenses , dichroic mirrors , and sealing windows excluding a wavelength conversion element in the apparatus between optical fibers F1 and F2 on the input side and optical fibers F3 and F4 on the output side, and on end surfaces of the optical fibers F3 and F4 on the output side. With this, even when light having a wavelength of a sum frequency component of signal light and excitation light is generated at the operation time of wavelength conversion of the wavelength conversion element, because the reflection suppressors suppress the reflection of unwanted light of the wavelength band, the unwanted light is unlikely to return to the wavelength conversion element and it is also possible to suppress a situation in which the unwanted light is mixed into the optical fibers F3 and F4.

In a wavelength conversion apparatus, reflection suppressors are provided on surfaces of optical elements indicating lenses , dichroic mirrors , and sealing windows excluding a wavelength conversion element in the apparatus between optical fibers F1 and F2 on the input side and optical fibers F3 and F4 on the output side, and on end surfaces of the optical fibers F3 and F4 on the output side. With this, even when light having a wavelength of a sum frequency component of signal light and excitation light is generated at the operation time of wavelength conversion of the wavelength conversion element, because the reflection suppressors suppress the reflection of unwanted light of the wavelength band, the unwanted light is unlikely to return to the wavelength conversion element and it is also possible to suppress a situation in which the unwanted light is mixed into the optical fibers F3 and F4.

A wavelength converter stabilizes output light intensity in which the light coupling efficiency to a light waveguide core is not easily varied. A mounting structure is adopted in which a substrate of a wavelength conversion element is a material with a lower refractive index for signal light than that of the core, and a support structure that suppresses elastic deformation by supporting the element through a contact at a tip end surface at a position corresponding to both end portions of the core at the occurrence of elastic deformation due to the thermal stress of the element is provided. The support structure is provided at a portion apart from a temperature control element at the top surface of a metal housing bottom surface member, and its top surface is disposed in the vicinity of a portion corresponding to both end portions of the core of the element in a support member.

A wavelength converter stabilizes output light intensity in which the light coupling efficiency to a light waveguide core is not easily varied. A mounting structure is adopted in which a substrate of a wavelength conversion element is a material with a lower refractive index for signal light than that of the core, and a support structure that suppresses elastic deformation by supporting the element through a contact at a tip end surface at a position corresponding to both end portions of the core at the occurrence of elastic deformation due to the thermal stress of the element is provided. The support structure is provided at a portion apart from a temperature control element at the top surface of a metal housing bottom surface member, and its top surface is disposed in the vicinity of a portion corresponding to both end portions of the core of the element in a support member.