Visible continuum generation using a femtosecond erbium-doped fiber laser and a silica nonlinear fiber.

Supercontinuum extending to visible wavelengths is generated in a hybrid silica nonlinear fiber pumped at 1560 nm by a femtosecond, erbium-doped fiber laser. The hybrid nonlinear fiber consists of a short length of highly nonlinear, germano-silicate fiber (HNLF) spliced to a length of photonic crystal fiber (PCF). A 2 cm length of HNLF provides an initial stage of continuum generation due to higher-order soliton compression and dispersive wave generation before launching into the PCF. The visible radiation is generated in the fundamental mode of the PCF.

Coherence of supercontinua generated by ultrashort pulses compressed in optical fibers.

Femtosecond fiber lasers together with nonlinear fibers are compact, reliable, all-fiber supercontinuum sources. Maintaining an all-fiber configuration, however, necessitates pulse compression in an optical fiber, which can lead to nonlinearities for subhundred femtosecond, nanojoule pulses. In this work we show that using large-mode-area fibers for pulse compression mitigates the nonlinearity, resulting in compressed pulses with significantly reduced satellite pulses. Consequently, supercontinua generated with these pulses are shown to have as much as a 10 dB increase in coherence fringe contrast. By using a hybrid highly nonlinear fiber-photonic crystal fiber, the continuum can be extended to visible wavelengths while still maintaining high coherence.

Distributed suppression of stimulated Raman scattering in an Yb-doped filter-fiber amplifier.

Suppression of stimulated Raman scattering (SRS) is demonstrated in a cladding-pumped fiber amplifier. The Yb-doped amplifier fiber design incorporates a high-index ring that resonantly couples SRS wavelengths out of the gain material, thus filtering the gain. Modeling shows that fiber asymmetry plays an important role in the filtering spectrum.

All-optical switching and multifrequency generation in a dual-core photonic crystal fiber.

We demonstrate all-optical switching at 1550 nm between two weakly coupled cores in a photonic crystal fiber for intensities up to 0.5 TW/cm2. Spectrum analysis at higher intensities reveals that the output was dominated by continuum generation primarily towards shorter wavelengths.

Cementoma--presentation predicates approach.

Cementomas are benign jaw tumors that originate from periodontal ligament elements. Four classifications of cementomas are described: periapical fibrous dysplasia, benign cementoblastoma, cementifying fibroma, and florid osseous dysplasia. Usual treatment regimens vary from observation to limited surgical resection based upon tumor type and clinical characteristics. We present an unusual case report of an extensive cementifying fibroma that required mandibular and inferior alveolar nerve resection followed by osseous and neural reconstruction.

Nasal bone haemangiomas: rare entities treatable by craniofacial approach.

Three cases of haemangioma of the nasal bone are illustrative of a rare clinical entity. These were treated by current craniofacial surgical techniques. The advantages of this approach are obvious minimising of the facial deformity, obtaining autologous cranial bone graft and rigid fixation to enhance stability and minimise resorption.