Optical locking of two semiconductor lasers through high-order Brillouin Stokes components in optical fiber

A novel technique for optical injection locking of two semiconductor lasers through high-order Brillouin Stokes components in optical fiber is proposed and experimentally demonstrated. The configuration potentially provides microwave signals generation at manifold Brillouin frequency without high-frequency external modulator and generator. Significant narrowing of the locked slave semiconductor laser linewidth was recorded.     

Generation of radiation in tunnel-coupled waveguides with positive and negative refractive indices

The possibility of generating microwave radiation in tunnel-coupled planar waveguides, one of which is made of a metamaterial and is characterized by a negative refractive index in the corresponding frequency range, while the other waveguide is active and exhibits positive refractive index, is demonstrated. The model of a tunable distributed feedback laser, in which the dependence of the refractive index of the metamaterial on the external magnetic field allows controlling the oscillation frequency, is proposed.     

Evolution of surface plasmon–polariton wave in a thin metal film: The modulation‐instability effect

The modulation instability development of intensive surface plasmon–polariton waves in a thin metal film is studied. It is shown both analytically and numerically that the modulation‐instability effect can give rise to spatial redistribution and longitudinal localization of surface plasmon–polariton wave energy on the subwavelength scale. Analytical expressions for the driving parameters of the modulation instability process ? nonlinearity and dispersion ? are derived. The impact of the film thickness and dielectric permittivities of constituents on the dynamics of surface plasmon–polariton wave transformation is considered. Numerical simulations show that in the layer structure comprising a silver film of subwavelength thickness a train of subpicosecond optical pulses with high repetition rate can be generated.

     

Dynamics of a Wave Packet of Whispering-Gallery-Mode Type in an Optical Waveguide in the Presence of a Traveling Refractive-Index Wave

It is demonstrated that strong ultrafast modulation of a tunneling wave packet of the whispering-gallery-mode type can be implemented in a cylindrical optical waveguide exhibiting spatiotemporal inhomogeneity induced by a travelling refractive-index wave. The corresponding optical waveguides can be used for efficient generation of picosecond and subpicosecond laser pulses.     

Cooperative stimulated Brillouin and Rayleigh backscattering process in optical fiber

We observed an unusually narrow spectrum of Stokes field and Gaussian statistics of Stokes power for the stimulated Brillouin scattering (SBS) process in 300-m single-mode optical fiber with high Rayleigh losses. The measured characteristics of the Stokes radiation indicate that SBS lasing took place in the fiber. The effect is explained as the result of dynamic distributed feedback that is due to double Rayleigh scattering (RS) of the Stokes field. The results of numerical simulation of the cooperative SBS-RS process in fiber are in good agreement with experimental results.     

Amplification of chirped pulses in inhomogeneous three-level active optical fibers

The possibility of efficient amplification of self-similar frequency-modulated wave packets in amplifiers inhomogeneous along their length is investigated. Special features of the amplification dynamics in erbium fiber amplifiers that operate according to the three-level scheme are analyzed. It is shown that active optical fibers with a specially designed profile of the normal group-velocity dispersion allow amplifying subpicosecond pulses with high efficiency.     

Low-threshold all-fiber 1000 nm supercontinuum source based on highly non-linear fiber

We present an highly efficient all-fiber compact supercontinuum source that exhibits a nearly flat spectrum from 1.1 μm to 2.1 μm. This broadband infrared optical source is made-up of a highly non-linear fiber pumped by a 1.55 μm self-Q-switched Er-Brillouin nanosecond pulsed fiber laser, which in turn is pumped by a low-power 1480 nm laser diode. In this work we highlight the great potential of highly non-linear fiber for supercontinuum generation with respect to conventional dispersion-shifted fiber by demonstrating a significant 10 dB power enhancement in the short wavelength side of the supercontinuum.