Dmitri Vladislavovich Kuksenkov

Single-mode all-silica photonic bandgap fiber with 20-μm mode-field diameter

An all-silica photonic bandgap fiber with a cladding index difference of approximately 2 % and diameter-to-pitch ratio (d/Λ) of 0.12 was fabricated and studied. To our knowledge, this is the first report on the properties of photonic bandgap fiber with such a small d/Λ. The fiber is single-mode in the fundamental bandgap. The mode field diameter in the 1000-1200 nm wavelength range is 19-20 μm. The minimum loss in the same range is 20 dB/km for a 30-cm bending diameter. In our opinion, all-silica photonic bandgap fiber can serve as a potential candidate for achieving single-mode propagation with a large mode area.

A novel dispersion monitoring technique based on four-wave mixing in optical fiber

We propose a novel dispersion monitoring method based on four-wave mixing (FWM) or parametric amplification effect in optical fiber. The signal pulse stream, which is used as a parametric pump, is mixed with a weak continuous wave light at a different wavelength in a fiber. Due to the FWM effect, a so-called idler light is created at a wavelength symmetric in respect to the pump. The output idler power can be measured and is dependent on the pulsewidth and, therefore, accumulated residual dispersion of the input signal. The concept was successfully demonstrated with 40-Gb/s return-to-zero signal. This approach potentially works for data rates up to terabits per second and can be applied to provide a feedback for automatic dispersion compensation.

Transmission of 112 Gb/s PM-QPSK signals over up to 635 km of multimode optical fiber.

We investigate transmission of 112 Gb/s PM-QPSK signals over 50 μm core diameter OM3 multimode fiber using the center launch approach. We demonstrate successful transmission of 16 DWDM channels over a distance of 635 km.

Multiple-wavelength synthetic green laser source for speckle reduction

We demonstrate a frequency-converted green laser source simultaneously emitting three spectral lines with nearly equal intensity and ~ 0.5 nm separation, enabling a factor of √3 reduction of speckle contrast in pico-projector applications. The source consists of an external cavity 1060 nm diode laser pump with dual-wavelength reflection provided by a volume Bragg grating and a quasi-periodically poled MgO-doped lithium niobate waveguide engineered to phase-match multiple-wavelength frequency conversion. 62 mW output power and 33% conversion efficiency are demonstrated.

Broad-band dynamic dispersion compensation in nonlinear fiber-based device

In this paper we report on the design, numerical simulation and experimental testing of a novel dynamic dispersion compensation device based on self-phase modulation (SPM) in nonlinear fiber. The proposed all-fiber device is inherently simple and presents several unique advantages, most notably the potential for a broad-band operation covering all wave-length division multiplexing (WDM) channels of a system and the ability to address variable amounts of residual dispersion in each individual channel. Dynamic compensation ranges of up to 140 ps/nm for a single-stage and 240 ps/nm for a two-stage device are demonstrated with 40 Gb/s CS-RZ signal. It is shown that the device can operate with a minimum channel spacing of 200 GHz. For a two-stage device with inter-stage spectral filtering, simultaneous dynamic dispersion compensation (130 ps/nm for 1 dB penalty) and 2R regeneration (2 dB receiver sensitivity improvement) are demonstrated.

On the origin of excess loss in highly GeO/sub 2/-doped single-mode MCVD fibers

Index profile grading and elimination of the central dip have yielded the lowest loss ever reported for modified chemical vapor deposition-made highly GeO/sub 2/-doped single-mode fibers (1.33 dB/km at 1550 nm for /spl Delta/=2.9%). Investigation of the angular distribution of scattering has shown that much of the optical loss in such fibers is due to anomalous scattering. This scattering arises in the region of the central dip in the refractive index profile and at the core-cladding interface.

Wavelength tunable stretched-pulse mode-locked all-fiber erbium ring laser with single polarization fiber.

A wavelength tunable stretched-pulse mode-locked all-fiber ring laser using single polarization fiber (SPF) was demonstrated. In this laser, a segment of SPF was used simultaneously as a polarizer and a tunable filter in the laser cavity. Self-starting mode-locking with femtosecond output pulses was demonstrated. A wavelength tuning of ~20nm was achieved by bending the SPF with different radii.

High power diode pumped single-transverse-mode Yb fiber laser operating at 978 nm

A single-mode Yb fiber laser delivering 450 mW at 978 nm is reported. The device consists of a tapered multimode Yb fiber pumped with a 2 W 920 nm broadstripe. The pumping scheme has advantages over double-clad fiber lasers when applied to 3-level laser systems.

Efficient generation of CW supercontinuum in optical fiber pumped by ASE light

We propose a new and efficient approach to generation of a continuous-wave supercontinuum in optical fiber pumped by an amplified spontaneous emission light. A bandwidth of 268 nm (at -15 dB level) with an average spectral density of 2.7 mW/nm is demonstrated

Simultaneous 2R regeneration and dynamic dispersion compensation at 40 Gb/s in a nonlinear fiber-based device

Simultaneous dynamic dispersion compensation (130 ps/nm range) and 2R regeneration (2 dB receiver sensitivity improvement) are demonstrated for a 40 Gb/s CS-RZ signal using soliton effect pulse compression and narrowband spectral filtering.