30 results about "Waveguide dispersion" patented technology

A modular, compact and widely tunable laser system for the efficient generation of high peak and high average power ultrashort pulses. Modularity is ensured by the implementation of interchangeable amplifier components. System compactness is ensured by employing efficient fiber amplifiers, directly or indirectly pumped by diode lasers. Peak power handling capability of the fiber amplifiers is expanded by using optimized pulse shapes, as well as dispersively broadened pulses. Dispersive broadening is introduced by dispersive pulse stretching in the presence of self-phase modulation and gain, resulting in the formation of high-power parabolic pulses. In addition, dispersive broadening is also introduced by simple fiber delay lines or chirped fiber gratings, resulting in a further increase of the energy handling ability of the fiber amplifiers. The phase of the pulses in the dispersive delay line is controlled to quartic order by the use of fibers with varying amounts of waveguide dispersion or by controlling the chirp of the fiber gratings. After amplification, the dispersively stretched pulses can be re-compressed to nearly their bandwidth limit by the implementation of another set of dispersive delay lines. To ensure a wide tunability of the whole system, Raman-shifting of the compact sources of ultrashort pulses in conjunction with frequency-conversion in nonlinear optical crystals can be implemented, or an Anti-Stokes fiber in conjunction with fiber amplifiers and Raman-shifters are used. A particularly compact implementation of the whole system uses fiber oscillators in conjunction with fiber amplifiers. Additionally, long, distributed, positive dispersion optical amplifiers are used to improve transmission characteristics of an optical communication system. Finally, an optical communication system utilizes a Raman amplifier fiber pumped by a train of Raman-shifted, wavelength-tunable pump pulses, to thereby amplify an optical signal which counterpropogates within the Raman amplifier fiber with respect to the pump pulses.

A planar dispersion compensator for an optical signal is provided. The compensator decomposes an inputted optical signal into N component signals separated by a fractional wavelength deltalambda. Each component signal has its path-length adjusted to induce a sufficient phase shift between input and output to change the group delay of the optical signal when recombined from each of the component signals. In this manner, pulse broadening can be compensated by selectively varying the induced phase shifts to produce the desired level of opposite group delay. Portions of the substrate of the planar waveguide are removed to improve thermal responsiveness of the path-length adjustment means.

The invention belongs to the technical field of satellite communication antennas, and particularly relates to a method for designing a slow wave structure of a CTS antenna and a VICTS antenna. Firstly, a parallel plate waveguide dispersion equation model based on a uniform rectangular comb tooth slow wave structure is established to establish a parallel-plate waveguide dispersion equation model with a uniform rectangular comb tooth structure based on horizontal radiation branching; according to the two dispersion equation models, obtaining a mapping relationship between an effective dielectricconstant of a horizontal radiation branching unit and rectangular comb tooth structure parameters and the height of a parallel plate waveguide; finally according to the VICTS antenna design requirements, choosing a variation rule, function or curve of the height of the parallel plate waveguide, and according to the obtained mapping relationship, selecting the corresponding rectangular comb toothstructure parameters under different parallel plate waveguide heights. According to the method for designing the slow wave structure of the CTS antenna and the VICTS antenna, by the nonlinear design on rectangular comb teeth which are of the slow wave structure in the VICTS antenna, while array optimization is achieved, it is ensured that parameters such as the gain of the antenna and the standing-wave ratio do not deteriorate or even are improved.

The invention discloses a novel wideband dielectric loaded gyro traveling wave tube high frequency system, and belongs to the technical field of microwave, millimeter wave and terahertz devices. The system comprises pre-bunching section, a linear amplification section, a nonlinear amplification section and an output gradual change section which are sequentially connected, and is characterized in that the pre-bunching section, the linear amplification section, the nonlinear amplification section and the output gradual change section comprise a metal circular waveguide shell and an annular lossless dielectric loading waveguide which is loaded in a mode of attaching to the circular waveguide inner wall, the linear amplification section is uniformly provided with rectangular lossy dielectric pieces in the angular direction, and the lossy dielectric pieces are distributed in a periodic manner along the axial direction. Dispersion characteristics of the whole high frequency structure are changed through loading the lossless dielectric waveguide, an electron beam curve and a waveguide dispersion curve are enabled to meet resonance conditions within a wide frequency band range, and wideband operating characteristics are ensured; and meanwhile, a gradually changing output structure is adopted, so that a problem of low output power brought about by low gain of a high frequency point is solved. The system disclosed by the invention not only can meet wideband operating requirements, but also can provide high microwave power output within the frequency band range.

The invention discloses a regulatable optical waveguide dispersion compensator controlled by binodal reverse-electrode orientation coupler, arranging parallel I / O optical waveguides in a part of the closed-loop optical waveguide microring to compose an orientation coupler, where the effective length of the orientation coupler is once to thrice as long as its coupled length and is a length influencing the coupling in the graded separation, two driving electrodes of the same length are arranged on the orientation coupler and reversely arranged on two waveguides composing the orientation coupler, thus composing the binodal reverse-electrode structural 2x2 input controllable orientation coupler. This structural regulable coupling mechanism can realize regulable coupling in the whole range and can have a bending shape, and even for a circular optical microring, it need not adopt special structure processing, thus unable to enlarge the circumference of the optical microring. This brings about extreme flexibility to the design and besides, it has extreme flexibility in designing and realizing multiple-stage cascade.

The invention provides an ultra-large bandwidth super-continuum spectrum laser source. The ultra-large bandwidth super-continuum spectrum laser source mainly comprises a pulse optical-fiber laser device, an optical fiber amplifier and a germanium oxide optical fiber, wherein the germanium oxide optical fiber is a step-index type optical fiber with a refractive structure, an optical fiber with a photonic crystal structure or a micro-structural optical fiber. The ultra-large bandwidth super-continuum spectrum laser source introduces positive waveguide dispersion through the germanium oxide optical fiber, can move zero dispersion points of the germanium oxide optical fiber from a 1.7-micron waveband to a nearby 1.5-micron waveband in the short waveguide direction, makes the zero dispersion points be close to the wave length of the pulse optical-fiber laser device and forms a group velocity dispersion curve of frequencies symmetrically distributed about the zero dispersion points. An output spectrum of the laser source can cover a middle-infrared waveband of visible light, the ultra-large bandwidth super-continuum spectrum laser source has the advantages of being of an all-fiber structure, low in cost, good in stability and the like and is easily popularized and used in the lots of fields of optical element performance testing, micro-imaging, biomedicines, broad-spectrum sensing, spectroscopy and the like in a wide-range mode.