116 results about "Nonlinear polarization" patented technology

The present invention applies microprocessing technique to utilize high refractive index of semiconductor material to prepare high quality of two-dimensional photon crystal with defect state and optical switch can be realized by utilizing high third order-nonlinear polarizability and quick response time of semiconductor material. The produced optical switch can be widely used in field of optical communication and optical computer.

The invention discloses a nonlinear polarization rotary mode-locked and wavelength tunable type L-waveband femtosecond Er-doped fiber laser and belongs to wavelength tunable type femtosecond pulse lasers. The nonlinear polarization rotary mode-locked and wavelength tunable type L-waveband femtosecond Er-doped fiber laser comprises a pumping source and an optical fiber ring cavity, wherein the optical fiber ring cavity is formed by connecting a wavelength division multiplexer, Er-doped fibers, an optical fiber isolator, an optical fiber polarizer, an optical fiber coupler and optical fibers used in a polarization controller, the pumping source is connected with the pumping port of the wavelength division multiplexer, a public port of the wavelength division multiplexer is connected to the 80% output port of the optical fiber coupler after passing through the Er-doped fibers, the optical fiber isolator and the optical fiber polarizer in sequence, and the input end of the optical fiber coupler is connected to a signal port of the wavelength division multiplexer through the polarization controller; the optical fiber isolator is connected with the optical fiber polarizer through dispersion compensation fibers, and the other devices are connected through single-mode optical fibers. The nonlinear polarization rotary mode-locked and wavelength tunable type L-waveband femtosecond Er-doped fiber laser has the advantages that the structure is simple and reliable, maintenance is convenient, external signal modulation is not needed, self-starting mode locking can be achieved, output pulses are narrow, the working performance is excellent, cost is low, and operation is easy.

A fiber laser cavity that includes a laser gain medium for receiving an optical input projection from a laser pump. The fiber laser cavity further includes a positive dispersion fiber segment and a negative dispersion fiber segment for generating a net negative dispersion for balancing a self-phase modulation (SPM) and a dispersion induced pulse broadening / compression in the fiber laser cavity for generating an output laser with a transform-limited pulse shape.

The invention relates to a multi-wavelength synchronous output fiber laser based on nonlinear polarization rotation mode locking, which comprises a semiconductor laser, a wavelength division multiplexer, a gain fiber, a first collimating mirror, a first half wave plate, a first quarter wave plate, a first polarization beam splitter, a Faraday isolator, a glaring grating, and a silver mirror. According to the first half wave plate, a nonlinear polarization rotation technology is adopted for mode locking, a saturable absorber which is likely to be damaged can be prevented from being used, and the stability of the laser is enhanced. According to the same laser gain fiber and the nonlinear polarization mode locking device, the distance between two wavelengths under mutual cross phase modulation effects in the laser cavity is increased, and thus, a cavity length misadjustment range for two laser cavities in the case of synchronous mode locking can be increased. Through changing the angle of a beam-splitting grating, the output wavelength of the laser can be tuned, the gap between the two wavelengths can be changed through changing the position of the collimator in the spectral space, and through changing the position of the collimator away from the beam-splitting grating, the pulse spectral width and the pulse width of laser output pulses can be changed.

A fiber laser cavity that includes a laser gain medium for receiving an optical input projection from a laser pump, wherein the laser cavity further includes a normal dispersion fiber segment with a β″>0 where β″ representing a fiber dispersion, and an anomalous dispersion fiber segment with the β″<0 for generating a net anomalous dispersion for balancing a self-phase modulation (SPM) and a dispersion induced pulse broadening / compression in the fiber laser cavity for generating an output laser with a transform-limited pulse shape wherein the segment with the anomalous dispersion further includes a Photonic Crystal (PC), a Photonic Bandgap (PBG) or a higher order mode (HOM) fiber.

The invention provides a space structure optical fiber laser based on two-dimensional nanomaterial mode locking. The space structure optical fiber laser comprises a pumping source used for outputting pumping laser, and an annular cavity optical path, wherein one part of the annular cavity optical path consists of gain optical fibers; the space structure optical fiber laser also comprises a two-dimensional nanomaterial saturable absorber used for mode locking, a space structure used for forming nonlinear polarization rotation and realizing hybrid mode locking, and a wavelength division multiplexer used for coupling light into the annular cavity optical path. According to the space structure optical fiber laser based on the two-dimensional nanomaterial mode locking provided by the invention, the space structure optical fiber laser mode locking is realized by adopting the two-dimensional nanomaterial saturable absorber and the space structure for forming nonlinear polarization rotation for realizing the hybrid mode locking; the optical fiber laser is compact and small in structure, relatively low in cost, and applicable to duplication in production and assembling; and the optical fiber laser has the advantages of one-way laser output, high repetition frequency, pulse width lower than 100fs magnitude, high stability, high optical beam quality and the like, so that the optical fiber laser can be widely applied to national defense, industries, medical treatment, scientific research and the like.