Simultaneous Pulse Compression Research Articles

Nonlinear pulse combining and pulse compression in multi-core fibers.

We demonstrate light pulse combining and pulse compression using a continuous-discrete nonlinear system implemented in a multi-core fiber (MCF). It is shown that the pulses initially injected into all of the cores of a ring MCF are combined by nonlinearity into a small number of cores with simultaneous pulse compression. We demonstrate the combining of 77% of the energy into one core with pulse compression over 14× in a 20-core MCF. We also demonstrate that a suggested scheme is insensitive to the phase perturbations. Nonlinear spatio-temporal pulse manipulation in multi-core fibers can be exploited for various applications, including pulse compression, switching, and combining.

Ultrafast multi-wavelength switch based on dynamics of spectrally-shifted solitons in a dual‑core photonic crystal fiber

Nonlinear propagation of ultrafast near infrared pulses in anomalous dispersion region of dual-core photonic crystal fiber was studied. Polarization tunable soliton-based nonlinear switching at multiple non-excitation wavelengths was demonstrated experimentally for fiber excitation by 100 fs pulses at 1650 nm. The highest-contrast switching was obtained with the fiber length of just 14 mm, which is significantly shorter compared to the conventional non-solitonic in-fiber switching based on nonlinear optical loop mirror. Advanced numerical simulations show good agreement with the experimental results, suggesting that the underlying dual-core soliton fission process supports nonlinear optical switching and simultaneous pulse compression to few-cycle durations at the level of 20 fs.

Multiple focusing with adaptive time-reversal mirror.

Recently, adaptivity was introduced to time-reversal mirror to steer the nulls, and referred to as an adaptive time-reversal mirror (ATRM) [J. S. Kim, H. C. Song, and W. A. Kuperman, J. Acoust. Soc. Am. 109, 1817-1825 (2001)]. In this study, ATRM is extended to simultaneous multiple focusing in an ocean waveguide. The multiple focusing is achieved by imposing a set of constraints in the formulation to find the weight vectors. The algorithm is applied to the long-range underwater acoustic communication to show, via simulation, that the simultaneous pulse compression at multiple receiving locations is achieved.

Simultaneous pulse compression andDoppler processing with step frequencywaveform

The author models the step frequency waveform in which the frequency of successive pulses is increased linearly in discrete steps. It is shown how to simultaneously realise the pulse compression and pulse Doppler processing with this waveform to improve the signal to noise ratio and to discriminate against clutter for detection of moving targets.

Femtosecond pulse generation from semiconductor lasers using the soliton-effect compression technique

An experimental investigation of various aspects associated with the pulse quality achieved by the soliton effect pulse compression technique is presented. By using fiber birefringence advantageously in conjunction with a wave plate and a polarizer, simultaneous pulse compression and pulse reshaping is realized and this can eliminate the pedestal component inherently associated with this compression technique. A train of 185-fs high-quality pedestal-free pulses, which are the shortest pulses ever achieved using semiconductor lasers, has been successfully generated. The detrimental effect of higher order dispersion on compression and its dependence on group velocity dispersion is also investigated. The results show that it is possible to minimize this effect by using fibers with an appropriate value of dispersion.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Simultaneous mode selection and pulse compression of gain-switched pulses from a Fabry-Perot laser using a 40-mm chirped optical fiber grating

Simultaneous pulse compression and mode selection of gain-switched pulses from a Fabry-Perot semiconductor laser are demonstrated using a chirped optical fiber Bragg grating, which has transformed initially chirped 60-ps pulses from an inexpensive multimode laser into a train of 12-ps single-mode pulses with a side-mode suppression ratio of 15.2 dB. >

Pulse compression and traveling wave excitation scheme using a single dispersive element

A single dispersive element is shown to be sufficient for simultaneous pulse compression and tilting of the pulse front, and therefore well-suited for traveling-wave excitation of targets. It is shown that in all the previous arrangements used for traveling wave excitation, spatially dependent group velocity dispersion occurs along the target. A compensated arrangement is proposed that provides pulse compression at the target-plane and exact synchronism between the pump and the generated pulses for various targets.

Optical Processing Techniques for Simultaneous Pulse Compression and Beam Sharpening

A technique is described in which the separate techniques of beam sharpening (by synthetic antenna methods) and pulse compression are converted into a single two-dimensional operation, which is carried out with a coherent optical processor.